Electric for main power

[whb]

Rather than start this on the two stroke vs. four stroke thread I wonder if there are any decent electric motors for main power. ie. not trolling motors. What their battery use is and if anyone has had any good/bad indifferent experiences with same.

I suspect gas motors of any stripe will not be allowed that much longer on some of the inland lakes/rivers I would like to frequent more often.

Howard

[whb]

Rather than start this on the two stroke vs. four stroke thread I wonder if there are any decent electric motors for main power. ie. not trolling motors. What their battery use is and if anyone has had any good/bad indifferent experiences with same.

I suspect gas motors of any stripe will not be allowed that much longer on some of the inland lakes/rivers I would like to frequent more often.

Howard

[whb]

Rather than start this on the two stroke vs. four stroke thread I wonder if there are any decent electric motors for main power. ie. not trolling motors. What their battery use is and if anyone has had any good/bad indifferent experiences with same.

I suspect gas motors of any stripe will not be allowed that much longer on some of the inland lakes/rivers I would like to frequent more often.

Howard

[bainbridgeisland]

Some companies specialize in motors for marine propulsion use. For example, check out Soloman Technologies Inc at www.solomantechnologies.com. (http://www.solomantechnologies.com.)

How much power do you need? Today, power density is poor because of battery storage capacity. This means you need to adjust speed and range expectations to the storage capacity available. For normal shape boats, about one times the square root of the waterline length is a reasonable top speed. Some exciting things are in the works today as fuel cell technology looks more promising each year. Some companies are already building boats designed to replace generators with fuel cells. For example check out Atlantis Yachts at www.atlantisyachts.com. (http://www.atlantisyachts.com.)

As you probably know, all electric motors are not suitable for marine propulsion. But where you place the motor is also important. Ever wonder why trolling motors have such crummy little props? Trolling motors are torque limited. They can’t drive larger diameter props without risk of damage to the motor. For most motors used for marine propulsion, the diameter of the prop is limited to roughly the diameter of the motor.

[bainbridgeisland]

Some companies specialize in motors for marine propulsion use. For example, check out Soloman Technologies Inc at www.solomantechnologies.com. (http://www.solomantechnologies.com.)

How much power do you need? Today, power density is poor because of battery storage capacity. This means you need to adjust speed and range expectations to the storage capacity available. For normal shape boats, about one times the square root of the waterline length is a reasonable top speed. Some exciting things are in the works today as fuel cell technology looks more promising each year. Some companies are already building boats designed to replace generators with fuel cells. For example check out Atlantis Yachts at www.atlantisyachts.com. (http://www.atlantisyachts.com.)

As you probably know, all electric motors are not suitable for marine propulsion. But where you place the motor is also important. Ever wonder why trolling motors have such crummy little props? Trolling motors are torque limited. They can’t drive larger diameter props without risk of damage to the motor. For most motors used for marine propulsion, the diameter of the prop is limited to roughly the diameter of the motor.

[bainbridgeisland]

Some companies specialize in motors for marine propulsion use. For example, check out Soloman Technologies Inc at www.solomantechnologies.com. (http://www.solomantechnologies.com.)

How much power do you need? Today, power density is poor because of battery storage capacity. This means you need to adjust speed and range expectations to the storage capacity available. For normal shape boats, about one times the square root of the waterline length is a reasonable top speed. Some exciting things are in the works today as fuel cell technology looks more promising each year. Some companies are already building boats designed to replace generators with fuel cells. For example check out Atlantis Yachts at www.atlantisyachts.com. (http://www.atlantisyachts.com.)

As you probably know, all electric motors are not suitable for marine propulsion. But where you place the motor is also important. Ever wonder why trolling motors have such crummy little props? Trolling motors are torque limited. They can’t drive larger diameter props without risk of damage to the motor. For most motors used for marine propulsion, the diameter of the prop is limited to roughly the diameter of the motor.

[The Schooner Etain]

Solomon Technologies does seem to make a very fine electric engine. I'm already looking at having one put in my boat. It's interesting the responses I get when I tell people I'm putting in an electric. One of my favorites was a comment by another sailor who noticed:

"Well, you might want the power from a diesel, ya know, like to get you off a lee shore."

I didn't have the heart to tell him that a good sailor doesn't find himself on a lee shore, because alittle bit of forethought keeps you out of those situations. Some people seem to forget that there are still cruisers sailing around without ANY engines at all.

As for the battery question. Solomon Technologies sent me this info.

Range: How far or how fast can I go are two of the most asked questions with an electric or hybrid STI system. Both questions are dependent upon the boat, the STI configuration and sailing style. Systems are configured to match your speed and range expectations. Below is an example of a few calculations relating to range. These calculations are based on operating on battery power and assume no regeneration of any form. Regeneration from the prop, wind generator, solar panels or gensets recharge the system, thus extending motoring range.

An example of motoring range for a Day Sailor from fully charged standard Group 31 105 amp hour 144v battery bank. Day Sailor configuration assumes motoring of three hours per sail (a half hour motoring from dock to wind, sail for 2-5 hours and a half hour motoring back in-, at 24 amps leaves 2 ½ hours of motor power and does not include any factor for regeneration).


Cruiser Day Sailor/Cruiser


ST74 12 14 hrs 7 hrs
ST74 24 7 hrs 3.5 hrs
ST74 36 4.6 hrs 2.3 hrs
ST74 48 3.5 hrs 1.75 hrs
ST74 60 2.8 hrs 1.4 hrs
ST74 72 2.3 hrs 1.25 hrs


Speed is a factor of hull style, prop size and sea conditions. Typically we configure our systems to sustain hull speed.

Regen rates about 1-4AMPs @ 144 volts in winds between 8-20 knots. A day sailor can recharge the battery bank in 3-5 hours of sailing after an hour of motoring. Power is also generated when motoring, in heavier sea conditions, the motor automatically goes into regen mode when “sliding down each wave”.

The battery bank can be recharged by solar panels and wind generators, keep in mind the AMP output of most solar panels and wind gens are at 12 volts. To calculate their recharge contribution for a 144vDC STI system divide the output AMP’s by 12 (a 12 amp solar panel or wind generator will recharge the STI battery bank at 1 amp. In this example 5 hours of solar/wind charging will restore 5 amps.) Keep in mind solar panels like batteries can be wired in series, 12 12v panels can be wired to produce 144v output to the battery bank.

In the chart there they sent me the info on the ST74 motor, which would be the size for my boat. The second is the amp hour draw, the next the estimated continuous motoring range on a charged 210 amp hour battery bank, and the last is the estimated continuous motoring range on a charged 105 amp hour battery bank. I hope that helps.

Chris

[The Schooner Etain]

Solomon Technologies does seem to make a very fine electric engine. I'm already looking at having one put in my boat. It's interesting the responses I get when I tell people I'm putting in an electric. One of my favorites was a comment by another sailor who noticed:

"Well, you might want the power from a diesel, ya know, like to get you off a lee shore."

I didn't have the heart to tell him that a good sailor doesn't find himself on a lee shore, because alittle bit of forethought keeps you out of those situations. Some people seem to forget that there are still cruisers sailing around without ANY engines at all.

As for the battery question. Solomon Technologies sent me this info.

Range: How far or how fast can I go are two of the most asked questions with an electric or hybrid STI system. Both questions are dependent upon the boat, the STI configuration and sailing style. Systems are configured to match your speed and range expectations. Below is an example of a few calculations relating to range. These calculations are based on operating on battery power and assume no regeneration of any form. Regeneration from the prop, wind generator, solar panels or gensets recharge the system, thus extending motoring range.

An example of motoring range for a Day Sailor from fully charged standard Group 31 105 amp hour 144v battery bank. Day Sailor configuration assumes motoring of three hours per sail (a half hour motoring from dock to wind, sail for 2-5 hours and a half hour motoring back in-, at 24 amps leaves 2 ½ hours of motor power and does not include any factor for regeneration).


Cruiser Day Sailor/Cruiser


ST74 12 14 hrs 7 hrs
ST74 24 7 hrs 3.5 hrs
ST74 36 4.6 hrs 2.3 hrs
ST74 48 3.5 hrs 1.75 hrs
ST74 60 2.8 hrs 1.4 hrs
ST74 72 2.3 hrs 1.25 hrs


Speed is a factor of hull style, prop size and sea conditions. Typically we configure our systems to sustain hull speed.

Regen rates about 1-4AMPs @ 144 volts in winds between 8-20 knots. A day sailor can recharge the battery bank in 3-5 hours of sailing after an hour of motoring. Power is also generated when motoring, in heavier sea conditions, the motor automatically goes into regen mode when “sliding down each wave”.

The battery bank can be recharged by solar panels and wind generators, keep in mind the AMP output of most solar panels and wind gens are at 12 volts. To calculate their recharge contribution for a 144vDC STI system divide the output AMP’s by 12 (a 12 amp solar panel or wind generator will recharge the STI battery bank at 1 amp. In this example 5 hours of solar/wind charging will restore 5 amps.) Keep in mind solar panels like batteries can be wired in series, 12 12v panels can be wired to produce 144v output to the battery bank.

In the chart there they sent me the info on the ST74 motor, which would be the size for my boat. The second is the amp hour draw, the next the estimated continuous motoring range on a charged 210 amp hour battery bank, and the last is the estimated continuous motoring range on a charged 105 amp hour battery bank. I hope that helps.

Chris

[The Schooner Etain]

Solomon Technologies does seem to make a very fine electric engine. I'm already looking at having one put in my boat. It's interesting the responses I get when I tell people I'm putting in an electric. One of my favorites was a comment by another sailor who noticed:

"Well, you might want the power from a diesel, ya know, like to get you off a lee shore."

I didn't have the heart to tell him that a good sailor doesn't find himself on a lee shore, because alittle bit of forethought keeps you out of those situations. Some people seem to forget that there are still cruisers sailing around without ANY engines at all.

As for the battery question. Solomon Technologies sent me this info.

Range: How far or how fast can I go are two of the most asked questions with an electric or hybrid STI system. Both questions are dependent upon the boat, the STI configuration and sailing style. Systems are configured to match your speed and range expectations. Below is an example of a few calculations relating to range. These calculations are based on operating on battery power and assume no regeneration of any form. Regeneration from the prop, wind generator, solar panels or gensets recharge the system, thus extending motoring range.

An example of motoring range for a Day Sailor from fully charged standard Group 31 105 amp hour 144v battery bank. Day Sailor configuration assumes motoring of three hours per sail (a half hour motoring from dock to wind, sail for 2-5 hours and a half hour motoring back in-, at 24 amps leaves 2 ½ hours of motor power and does not include any factor for regeneration).


Cruiser Day Sailor/Cruiser


ST74 12 14 hrs 7 hrs
ST74 24 7 hrs 3.5 hrs
ST74 36 4.6 hrs 2.3 hrs
ST74 48 3.5 hrs 1.75 hrs
ST74 60 2.8 hrs 1.4 hrs
ST74 72 2.3 hrs 1.25 hrs


Speed is a factor of hull style, prop size and sea conditions. Typically we configure our systems to sustain hull speed.

Regen rates about 1-4AMPs @ 144 volts in winds between 8-20 knots. A day sailor can recharge the battery bank in 3-5 hours of sailing after an hour of motoring. Power is also generated when motoring, in heavier sea conditions, the motor automatically goes into regen mode when “sliding down each wave”.

The battery bank can be recharged by solar panels and wind generators, keep in mind the AMP output of most solar panels and wind gens are at 12 volts. To calculate their recharge contribution for a 144vDC STI system divide the output AMP’s by 12 (a 12 amp solar panel or wind generator will recharge the STI battery bank at 1 amp. In this example 5 hours of solar/wind charging will restore 5 amps.) Keep in mind solar panels like batteries can be wired in series, 12 12v panels can be wired to produce 144v output to the battery bank.

In the chart there they sent me the info on the ST74 motor, which would be the size for my boat. The second is the amp hour draw, the next the estimated continuous motoring range on a charged 210 amp hour battery bank, and the last is the estimated continuous motoring range on a charged 105 amp hour battery bank. I hope that helps.

Chris

[J. Dillon]

Saw this on a 25' gaff rigger in Brooklyn ME
http://www.imagestation.com/picture/sraid28/p682e498b20a8b52a57b13b07196f4e49/fe0f3f2f.jpg

[J. Dillon]

Saw this on a 25' gaff rigger in Brooklyn ME
http://www.imagestation.com/picture/sraid28/p682e498b20a8b52a57b13b07196f4e49/fe0f3f2f.jpg

[J. Dillon]

Saw this on a 25' gaff rigger in Brooklyn ME
http://www.imagestation.com/picture/sraid28/p682e498b20a8b52a57b13b07196f4e49/fe0f3f2f.jpg

[blisspacket]

I too happen to like the trolling motor answer. Like an outboard, it's quickly installed/removed. And I used briefly a MinnKota 50lb thrust on my 6500lb gaff cutter; it always got me home, but once there tight maneuvering demanded more.

To get a good perspective, I recommend
http://clubs.yahoo.com/clubs/electricboats.
I'd also forward you in good faith to www.ecycle.com. (http://www.ecycle.com.) Both ecycle and MinnKota made a presentation to the Electric Boat Association meeting at StMichael's for the MidAtlantic Small Craft Festival. I think there are photos in the club news of ecycle's product. There is one aspect of electric motors (inboard) that is sometimes overlooked: they can be buzzynoisy. That's a point to consider, because the finest feature that I enjoy in electric boating is the faint hum of my trolling motor.
The MK people seem intent on producing more primary power motors, so that is somewhere in the future. As of now they tout two 65lb thrust tendems for their only primary propulsion offerings. I used their 101 lb thrust on the rudder of my Pearson Packet and could get 5.5knots at some 30amps, 36volts. VxA=W divided by 745=hp, so that's about 1.2 hp to translate to units I understand. How long you go is merely a function of how many batteries you want to carry, no matter whose powerplant.

[blisspacket]

I too happen to like the trolling motor answer. Like an outboard, it's quickly installed/removed. And I used briefly a MinnKota 50lb thrust on my 6500lb gaff cutter; it always got me home, but once there tight maneuvering demanded more.

To get a good perspective, I recommend
http://clubs.yahoo.com/clubs/electricboats.
I'd also forward you in good faith to www.ecycle.com. (http://www.ecycle.com.) Both ecycle and MinnKota made a presentation to the Electric Boat Association meeting at StMichael's for the MidAtlantic Small Craft Festival. I think there are photos in the club news of ecycle's product. There is one aspect of electric motors (inboard) that is sometimes overlooked: they can be buzzynoisy. That's a point to consider, because the finest feature that I enjoy in electric boating is the faint hum of my trolling motor.
The MK people seem intent on producing more primary power motors, so that is somewhere in the future. As of now they tout two 65lb thrust tendems for their only primary propulsion offerings. I used their 101 lb thrust on the rudder of my Pearson Packet and could get 5.5knots at some 30amps, 36volts. VxA=W divided by 745=hp, so that's about 1.2 hp to translate to units I understand. How long you go is merely a function of how many batteries you want to carry, no matter whose powerplant.

[blisspacket]

I too happen to like the trolling motor answer. Like an outboard, it's quickly installed/removed. And I used briefly a MinnKota 50lb thrust on my 6500lb gaff cutter; it always got me home, but once there tight maneuvering demanded more.

To get a good perspective, I recommend
http://clubs.yahoo.com/clubs/electricboats.
I'd also forward you in good faith to www.ecycle.com. (http://www.ecycle.com.) Both ecycle and MinnKota made a presentation to the Electric Boat Association meeting at StMichael's for the MidAtlantic Small Craft Festival. I think there are photos in the club news of ecycle's product. There is one aspect of electric motors (inboard) that is sometimes overlooked: they can be buzzynoisy. That's a point to consider, because the finest feature that I enjoy in electric boating is the faint hum of my trolling motor.
The MK people seem intent on producing more primary power motors, so that is somewhere in the future. As of now they tout two 65lb thrust tendems for their only primary propulsion offerings. I used their 101 lb thrust on the rudder of my Pearson Packet and could get 5.5knots at some 30amps, 36volts. VxA=W divided by 745=hp, so that's about 1.2 hp to translate to units I understand. How long you go is merely a function of how many batteries you want to carry, no matter whose powerplant.

[whb]

Thanks people,

I think that electric is probably going to be the way for me to go. I spend most of my time on a river that gets quite low so a light weight motor that I can pull up in a hurry where it is shallow is a good thing. I have been designing a pontoon boat that theoretically will draw 3 to 4 inches.

The other thing I am considering is sale but it may not be compatible with the river.

Howard

Merry Christmas to all and to all a good night.

[whb]

Thanks people,

I think that electric is probably going to be the way for me to go. I spend most of my time on a river that gets quite low so a light weight motor that I can pull up in a hurry where it is shallow is a good thing. I have been designing a pontoon boat that theoretically will draw 3 to 4 inches.

The other thing I am considering is sale but it may not be compatible with the river.

Howard

Merry Christmas to all and to all a good night.

[whb]

Thanks people,

I think that electric is probably going to be the way for me to go. I spend most of my time on a river that gets quite low so a light weight motor that I can pull up in a hurry where it is shallow is a good thing. I have been designing a pontoon boat that theoretically will draw 3 to 4 inches.

The other thing I am considering is sale but it may not be compatible with the river.

Howard

Merry Christmas to all and to all a good night.

[Frank Wentzel]

What counts in propulsion are available horsepower and the maximum continuous time for which you need this horsepower. Neither Solomon Technologies nor Solomon himself can change the basic rule:
1 horsepower equals 750 watts of energy (approx.)

A six-volt golf cart battery is a compact, easily handled, readily available, inexpensive power storage device. They can be connected in series/ parallel to get almost any voltage or current you need. The batteries are rated by the number of minutes they can provide a current of 75 amps. Therefore an EV-105 can provide rated output for 105 minutes or 1.75 hours. Each battery in your system can therefore provide 0.6 horsepower (6 X 75/750) for 1.75 hours. That works out to 1.05 horsepower/hours (my new measurement system) per battery. (Note that this is assuming full discharge of the battery. In order to insure acceptable life lead-acid batteries should not be discharged much below 50 percent of rated capacity.)

Using the above data, and making the assumption that you require 4 horsepower to move your boat at an acceptable speed and that you want 4 hours of power your required energy storage capacity can be met with 16 golf cart batteries. (Of course this also assumes a motor that can operate on a voltage that can be provided by some combination of 16 batteries.) At an average weight of 60 pounds per battery that works out to 960 pounds. And therein lies the rub - even assuming the weight savings of a high efficiency electric motor - batteries will outweigh an equivalent quantity of fuel by 50 to 1 or worse. If you follow the 50 percent depth-of-discharge rule the figure becomes 100 to 1.

I spent 20 years as an engineer in the battery industry and I really like the concept of clean, reliable power for boats and cars but the harsh reality is that the energy density of any battery system is terrible. I have seen the Solomon Technologies ads and claims and I find them impossible to believe, especially the claims about the battery recharging capability of their system. I note that no mainstream builder is using their system and I have heard no independent test data. With all the talk about them, I have not heard of anyone that actually bought one of their systems. There have only been references to the ST web page or to magazine articles that repeat, essentially verbatim, the contents of ST's ad copy. The battery industry has always been replete with charlatans and I am afraid this is just another rerun.

[Frank Wentzel]

What counts in propulsion are available horsepower and the maximum continuous time for which you need this horsepower. Neither Solomon Technologies nor Solomon himself can change the basic rule:
1 horsepower equals 750 watts of energy (approx.)

A six-volt golf cart battery is a compact, easily handled, readily available, inexpensive power storage device. They can be connected in series/ parallel to get almost any voltage or current you need. The batteries are rated by the number of minutes they can provide a current of 75 amps. Therefore an EV-105 can provide rated output for 105 minutes or 1.75 hours. Each battery in your system can therefore provide 0.6 horsepower (6 X 75/750) for 1.75 hours. That works out to 1.05 horsepower/hours (my new measurement system) per battery. (Note that this is assuming full discharge of the battery. In order to insure acceptable life lead-acid batteries should not be discharged much below 50 percent of rated capacity.)

Using the above data, and making the assumption that you require 4 horsepower to move your boat at an acceptable speed and that you want 4 hours of power your required energy storage capacity can be met with 16 golf cart batteries. (Of course this also assumes a motor that can operate on a voltage that can be provided by some combination of 16 batteries.) At an average weight of 60 pounds per battery that works out to 960 pounds. And therein lies the rub - even assuming the weight savings of a high efficiency electric motor - batteries will outweigh an equivalent quantity of fuel by 50 to 1 or worse. If you follow the 50 percent depth-of-discharge rule the figure becomes 100 to 1.

I spent 20 years as an engineer in the battery industry and I really like the concept of clean, reliable power for boats and cars but the harsh reality is that the energy density of any battery system is terrible. I have seen the Solomon Technologies ads and claims and I find them impossible to believe, especially the claims about the battery recharging capability of their system. I note that no mainstream builder is using their system and I have heard no independent test data. With all the talk about them, I have not heard of anyone that actually bought one of their systems. There have only been references to the ST web page or to magazine articles that repeat, essentially verbatim, the contents of ST's ad copy. The battery industry has always been replete with charlatans and I am afraid this is just another rerun.

[Frank Wentzel]

What counts in propulsion are available horsepower and the maximum continuous time for which you need this horsepower. Neither Solomon Technologies nor Solomon himself can change the basic rule:
1 horsepower equals 750 watts of energy (approx.)

A six-volt golf cart battery is a compact, easily handled, readily available, inexpensive power storage device. They can be connected in series/ parallel to get almost any voltage or current you need. The batteries are rated by the number of minutes they can provide a current of 75 amps. Therefore an EV-105 can provide rated output for 105 minutes or 1.75 hours. Each battery in your system can therefore provide 0.6 horsepower (6 X 75/750) for 1.75 hours. That works out to 1.05 horsepower/hours (my new measurement system) per battery. (Note that this is assuming full discharge of the battery. In order to insure acceptable life lead-acid batteries should not be discharged much below 50 percent of rated capacity.)

Using the above data, and making the assumption that you require 4 horsepower to move your boat at an acceptable speed and that you want 4 hours of power your required energy storage capacity can be met with 16 golf cart batteries. (Of course this also assumes a motor that can operate on a voltage that can be provided by some combination of 16 batteries.) At an average weight of 60 pounds per battery that works out to 960 pounds. And therein lies the rub - even assuming the weight savings of a high efficiency electric motor - batteries will outweigh an equivalent quantity of fuel by 50 to 1 or worse. If you follow the 50 percent depth-of-discharge rule the figure becomes 100 to 1.

I spent 20 years as an engineer in the battery industry and I really like the concept of clean, reliable power for boats and cars but the harsh reality is that the energy density of any battery system is terrible. I have seen the Solomon Technologies ads and claims and I find them impossible to believe, especially the claims about the battery recharging capability of their system. I note that no mainstream builder is using their system and I have heard no independent test data. With all the talk about them, I have not heard of anyone that actually bought one of their systems. There have only been references to the ST web page or to magazine articles that repeat, essentially verbatim, the contents of ST's ad copy. The battery industry has always been replete with charlatans and I am afraid this is just another rerun.

[nedL]

As I've said here before, used golf carts are a pretty cheap way to go. That is what powers this launch.

http://www.imagestation.com/picture/sraid28/p815d3a8877f072cbdc5f9705fbe48fa2/fe12645c.jpg

[nedL]

As I've said here before, used golf carts are a pretty cheap way to go. That is what powers this launch.

http://www.imagestation.com/picture/sraid28/p815d3a8877f072cbdc5f9705fbe48fa2/fe12645c.jpg

[nedL]

As I've said here before, used golf carts are a pretty cheap way to go. That is what powers this launch.

http://www.imagestation.com/picture/sraid28/p815d3a8877f072cbdc5f9705fbe48fa2/fe12645c.jpg

[Frank Wentzel]

Ned

That launch looks like a great way to go electric. A slippery hull with little in the way of extraneous displacement. As you say a golf cart motor is ideal. In general, today's electric motors are relatively high efficiency units. The difference in efficiency between a golf cart motor and the most expensive high efficiency motor is probably no more than 15 percent. The only problem I can think of is if the golf cart motor were to require a gearbox vs the high efficiency unit being a direct drive. But even then I think it would be difficult to justify the additional expense of the high E system.

/// Frank ///

[Frank Wentzel]

Ned

That launch looks like a great way to go electric. A slippery hull with little in the way of extraneous displacement. As you say a golf cart motor is ideal. In general, today's electric motors are relatively high efficiency units. The difference in efficiency between a golf cart motor and the most expensive high efficiency motor is probably no more than 15 percent. The only problem I can think of is if the golf cart motor were to require a gearbox vs the high efficiency unit being a direct drive. But even then I think it would be difficult to justify the additional expense of the high E system.

/// Frank ///

[Frank Wentzel]

Ned

That launch looks like a great way to go electric. A slippery hull with little in the way of extraneous displacement. As you say a golf cart motor is ideal. In general, today's electric motors are relatively high efficiency units. The difference in efficiency between a golf cart motor and the most expensive high efficiency motor is probably no more than 15 percent. The only problem I can think of is if the golf cart motor were to require a gearbox vs the high efficiency unit being a direct drive. But even then I think it would be difficult to justify the additional expense of the high E system.

/// Frank ///

[The Schooner Etain]

I noticed Frank, that you compared the weight of the batteries to the weught of the fuel someone would carry. Did you do that because you were thinking about the difference between the electric and an outboard? For me, it's the difference between the electric and an inboard. The weight of the batteries and the electric motor together would have to be compared with the weight of the diesel engine and fuel. The benefit of the batteries being that I can get the weight lower, and closer to the centerline, in the boat.

Chris

[The Schooner Etain]

I noticed Frank, that you compared the weight of the batteries to the weught of the fuel someone would carry. Did you do that because you were thinking about the difference between the electric and an outboard? For me, it's the difference between the electric and an inboard. The weight of the batteries and the electric motor together would have to be compared with the weight of the diesel engine and fuel. The benefit of the batteries being that I can get the weight lower, and closer to the centerline, in the boat.

Chris

[The Schooner Etain]

I noticed Frank, that you compared the weight of the batteries to the weught of the fuel someone would carry. Did you do that because you were thinking about the difference between the electric and an outboard? For me, it's the difference between the electric and an inboard. The weight of the batteries and the electric motor together would have to be compared with the weight of the diesel engine and fuel. The benefit of the batteries being that I can get the weight lower, and closer to the centerline, in the boat.

Chris

[Steve Souther]

The problem with getting the batteries low down in the bilge is electrolisis (sp?). If salt water gets to them it may start eating metal...

Steve

[Steve Souther]

The problem with getting the batteries low down in the bilge is electrolisis (sp?). If salt water gets to them it may start eating metal...

Steve

[Steve Souther]

The problem with getting the batteries low down in the bilge is electrolisis (sp?). If salt water gets to them it may start eating metal...

Steve

[Frank Wentzel]

Chris,

Point taken! The weight of a diesel engine is considerable and if you only expect to need a limited amount of power for a short time, the weight difference may be a minor issue.

However, when I specified the system I said four horsepower for four hours - which is fine for a launch. However, if you want the power of even a small Saab - about 10 horsepower - or you need to run for a whole day, the battery bank quickly gets into the ton and a half range. Combine that with a limit of 50 percent depth of discharge to get reasonable battery life and we are approaching 3 tons.

That said, I might still be all wet - we forgot to ask Howard about the size and type of boat he wants to power. Maybe a displacement type launch is suitable for his purpose, in which case electric power may still fill the bill.

Another note - I have said I find the information from ST a little hard to believe. That is based on the hype concerning electric cars. When I worked for Exide in the 70’s, they had several electric vehicles built for them (Sundancer). There was a lot of talk about regenerative braking but it turned out that the system didn't really produce a noticeable amount of power. I understand it is much the same situation with today’s electrics and hybrids.

The power input figures ST mentions are 24 amps at 144 volts – that works out to 4.6 hp. To replace the battery energy consumed during one hour of motoring (4.6 hp/hours) I will make some educated guesses (SWAGs). First, assume total energy losses of 50 percent to account for:
- Propeller inefficiency.
- Friction.
- Alternator losses.
- Battery charging inefficiency.
Therefore, will need to “intercept” 9.2 hp/hours of energy to recharge the battery. If the full five hours of battery charging time is available, to replace the energy consumed, your boat will have to oppose a drag equivalent to 1.84 horsepower. I’m afraid in an 8 to 10 knot breeze this would be quite difficult. A boat large enough to sail satisfactorily while experiencing that much drag would be rather under-powered with only a 4.6 hp auxiliary engine.

As I said, this is all based on a “SWAG”, so I may stand corrected. I would even welcome being proven wrong – I LIKE the idea of a practical electric auxiliary! I just have seen too much industry hype to hope for much at this time.

Just my $0.02

/// Frank ///

[Frank Wentzel]

Chris,

Point taken! The weight of a diesel engine is considerable and if you only expect to need a limited amount of power for a short time, the weight difference may be a minor issue.

However, when I specified the system I said four horsepower for four hours - which is fine for a launch. However, if you want the power of even a small Saab - about 10 horsepower - or you need to run for a whole day, the battery bank quickly gets into the ton and a half range. Combine that with a limit of 50 percent depth of discharge to get reasonable battery life and we are approaching 3 tons.

That said, I might still be all wet - we forgot to ask Howard about the size and type of boat he wants to power. Maybe a displacement type launch is suitable for his purpose, in which case electric power may still fill the bill.

Another note - I have said I find the information from ST a little hard to believe. That is based on the hype concerning electric cars. When I worked for Exide in the 70’s, they had several electric vehicles built for them (Sundancer). There was a lot of talk about regenerative braking but it turned out that the system didn't really produce a noticeable amount of power. I understand it is much the same situation with today’s electrics and hybrids.

The power input figures ST mentions are 24 amps at 144 volts – that works out to 4.6 hp. To replace the battery energy consumed during one hour of motoring (4.6 hp/hours) I will make some educated guesses (SWAGs). First, assume total energy losses of 50 percent to account for:
- Propeller inefficiency.
- Friction.
- Alternator losses.
- Battery charging inefficiency.
Therefore, will need to “intercept” 9.2 hp/hours of energy to recharge the battery. If the full five hours of battery charging time is available, to replace the energy consumed, your boat will have to oppose a drag equivalent to 1.84 horsepower. I’m afraid in an 8 to 10 knot breeze this would be quite difficult. A boat large enough to sail satisfactorily while experiencing that much drag would be rather under-powered with only a 4.6 hp auxiliary engine.

As I said, this is all based on a “SWAG”, so I may stand corrected. I would even welcome being proven wrong – I LIKE the idea of a practical electric auxiliary! I just have seen too much industry hype to hope for much at this time.

Just my $0.02

/// Frank ///

[Frank Wentzel]

Chris,

Point taken! The weight of a diesel engine is considerable and if you only expect to need a limited amount of power for a short time, the weight difference may be a minor issue.

However, when I specified the system I said four horsepower for four hours - which is fine for a launch. However, if you want the power of even a small Saab - about 10 horsepower - or you need to run for a whole day, the battery bank quickly gets into the ton and a half range. Combine that with a limit of 50 percent depth of discharge to get reasonable battery life and we are approaching 3 tons.

That said, I might still be all wet - we forgot to ask Howard about the size and type of boat he wants to power. Maybe a displacement type launch is suitable for his purpose, in which case electric power may still fill the bill.

Another note - I have said I find the information from ST a little hard to believe. That is based on the hype concerning electric cars. When I worked for Exide in the 70’s, they had several electric vehicles built for them (Sundancer). There was a lot of talk about regenerative braking but it turned out that the system didn't really produce a noticeable amount of power. I understand it is much the same situation with today’s electrics and hybrids.

The power input figures ST mentions are 24 amps at 144 volts – that works out to 4.6 hp. To replace the battery energy consumed during one hour of motoring (4.6 hp/hours) I will make some educated guesses (SWAGs). First, assume total energy losses of 50 percent to account for:
- Propeller inefficiency.
- Friction.
- Alternator losses.
- Battery charging inefficiency.
Therefore, will need to “intercept” 9.2 hp/hours of energy to recharge the battery. If the full five hours of battery charging time is available, to replace the energy consumed, your boat will have to oppose a drag equivalent to 1.84 horsepower. I’m afraid in an 8 to 10 knot breeze this would be quite difficult. A boat large enough to sail satisfactorily while experiencing that much drag would be rather under-powered with only a 4.6 hp auxiliary engine.

As I said, this is all based on a “SWAG”, so I may stand corrected. I would even welcome being proven wrong – I LIKE the idea of a practical electric auxiliary! I just have seen too much industry hype to hope for much at this time.

Just my $0.02

/// Frank ///

[Frank Wentzel]

Steve,

A quick glance at your car battery will demonstrate that batteries already provide their own electrolyte to corrode the battery terminals and wiring! The real problem with salt water is immersion. If salt water gets into the batteries they can start giving off chlorine gas! However this is only a problem with fully charged batteries, which means you have plenty of power available for the bilge pumps to keep the water level down. When the batteries have become flat from running the bilge pump, and the batteries are now under water, that is a strong indicator that the rest of the boat will soon follow! http://media5.hypernet.com/~dick/ubb/eek.gif

/// Frank ///

[Frank Wentzel]

Steve,

A quick glance at your car battery will demonstrate that batteries already provide their own electrolyte to corrode the battery terminals and wiring! The real problem with salt water is immersion. If salt water gets into the batteries they can start giving off chlorine gas! However this is only a problem with fully charged batteries, which means you have plenty of power available for the bilge pumps to keep the water level down. When the batteries have become flat from running the bilge pump, and the batteries are now under water, that is a strong indicator that the rest of the boat will soon follow! http://media5.hypernet.com/~dick/ubb/eek.gif

/// Frank ///

[Frank Wentzel]

Steve,

A quick glance at your car battery will demonstrate that batteries already provide their own electrolyte to corrode the battery terminals and wiring! The real problem with salt water is immersion. If salt water gets into the batteries they can start giving off chlorine gas! However this is only a problem with fully charged batteries, which means you have plenty of power available for the bilge pumps to keep the water level down. When the batteries have become flat from running the bilge pump, and the batteries are now under water, that is a strong indicator that the rest of the boat will soon follow! http://media5.hypernet.com/~dick/ubb/eek.gif

/// Frank ///

[KarlSchmid]

I've been using a 36-volt Advanced DC electric motor with a 3:1 reduction gear generating 4hp(continuous), powered by three 12-volt deep-cycle batteries, as the main propulsion system for my 19' Chesapeake Bay replica skiff for the past three seasons. The installation is a standard marine inboard arrangement with a shaft through the skeg, therefore it is going to be a very straightforward conversion when I re-power to diesel next month.

I'll spare you the many details of how I arrived at this decision, but not the least of the factors was the too-frequent experience, after a full day of fishing or idyllic cruising on the river, of taking over two hours to reach the launching ramp (less than 2 miles away) on depleted batteries, having too much pride to request a tow. Please think long and hard about how you want to use the boat, because this scenario besides annoying is also unsafe on a body of water with much high-speed boat traffic. Many of the inland lakes you refer to are also large, and you can find yourself just as far from the dock/ramp with batteries just as weak.

If after this cautionary rant, you decide to go for it, Bob Batson of Electric Vehicles of America (EVAmerica@aol.com) is a valuable consulting resource and they (EVA) have a catalogue of every possible component you would need to convert any vehicle to electric. If you are interested in buying a complete electric boat, Beckmann Boatshop LTD of Slocum, RI (401)783-1859 offers a couple of models with the same power system as mine, but more cushy (read faux-Victorian brass and fringe canopies, cushioned seats)accomodations. Lastly, I might be willing to discuss the future of my power plant (to be removed as a functional unit including box) off-fourm.

[KarlSchmid]

I've been using a 36-volt Advanced DC electric motor with a 3:1 reduction gear generating 4hp(continuous), powered by three 12-volt deep-cycle batteries, as the main propulsion system for my 19' Chesapeake Bay replica skiff for the past three seasons. The installation is a standard marine inboard arrangement with a shaft through the skeg, therefore it is going to be a very straightforward conversion when I re-power to diesel next month.

I'll spare you the many details of how I arrived at this decision, but not the least of the factors was the too-frequent experience, after a full day of fishing or idyllic cruising on the river, of taking over two hours to reach the launching ramp (less than 2 miles away) on depleted batteries, having too much pride to request a tow. Please think long and hard about how you want to use the boat, because this scenario besides annoying is also unsafe on a body of water with much high-speed boat traffic. Many of the inland lakes you refer to are also large, and you can find yourself just as far from the dock/ramp with batteries just as weak.

If after this cautionary rant, you decide to go for it, Bob Batson of Electric Vehicles of America (EVAmerica@aol.com) is a valuable consulting resource and they (EVA) have a catalogue of every possible component you would need to convert any vehicle to electric. If you are interested in buying a complete electric boat, Beckmann Boatshop LTD of Slocum, RI (401)783-1859 offers a couple of models with the same power system as mine, but more cushy (read faux-Victorian brass and fringe canopies, cushioned seats)accomodations. Lastly, I might be willing to discuss the future of my power plant (to be removed as a functional unit including box) off-fourm.

[KarlSchmid]

I've been using a 36-volt Advanced DC electric motor with a 3:1 reduction gear generating 4hp(continuous), powered by three 12-volt deep-cycle batteries, as the main propulsion system for my 19' Chesapeake Bay replica skiff for the past three seasons. The installation is a standard marine inboard arrangement with a shaft through the skeg, therefore it is going to be a very straightforward conversion when I re-power to diesel next month.

I'll spare you the many details of how I arrived at this decision, but not the least of the factors was the too-frequent experience, after a full day of fishing or idyllic cruising on the river, of taking over two hours to reach the launching ramp (less than 2 miles away) on depleted batteries, having too much pride to request a tow. Please think long and hard about how you want to use the boat, because this scenario besides annoying is also unsafe on a body of water with much high-speed boat traffic. Many of the inland lakes you refer to are also large, and you can find yourself just as far from the dock/ramp with batteries just as weak.

If after this cautionary rant, you decide to go for it, Bob Batson of Electric Vehicles of America (EVAmerica@aol.com) is a valuable consulting resource and they (EVA) have a catalogue of every possible component you would need to convert any vehicle to electric. If you are interested in buying a complete electric boat, Beckmann Boatshop LTD of Slocum, RI (401)783-1859 offers a couple of models with the same power system as mine, but more cushy (read faux-Victorian brass and fringe canopies, cushioned seats)accomodations. Lastly, I might be willing to discuss the future of my power plant (to be removed as a functional unit including box) off-fourm.

[whb]

Hi All,

Here's the problem. The boat will be used mostly on the Red Deer river in Alberta. It goes from being a class 4-5 whitewater river in the spring to an extremely shallow slow river in the late summer fall.

I have been trying to design a boat with a 4" draft but will likely have to go deeper to get the carrying capacity I want.

I had considered putting a tunnel in the bottom with a 4 stroke jet outboard at the end. This would actually sit 1/2 inch above the bottom of the boat.

This solution works and is common for the aluminum hunting/work boats used on shallow water.

However, the 4 stroke jets are way more expensive than what I want to do right now.

Our prevailing wind is either straight upriver or straight downriver. I'm tempted to build a flat bottom trimaran (Essentially a large canoe with smaller canoes for outriggers) and put a big ole viking square sail on it. I'll stick to using it when the wind is right. Not a lot of room to tack on the river.

Just playing with ideas now but something will click one of these days.

Thanks all,

Happy new year

[whb]

Hi All,

Here's the problem. The boat will be used mostly on the Red Deer river in Alberta. It goes from being a class 4-5 whitewater river in the spring to an extremely shallow slow river in the late summer fall.

I have been trying to design a boat with a 4" draft but will likely have to go deeper to get the carrying capacity I want.

I had considered putting a tunnel in the bottom with a 4 stroke jet outboard at the end. This would actually sit 1/2 inch above the bottom of the boat.

This solution works and is common for the aluminum hunting/work boats used on shallow water.

However, the 4 stroke jets are way more expensive than what I want to do right now.

Our prevailing wind is either straight upriver or straight downriver. I'm tempted to build a flat bottom trimaran (Essentially a large canoe with smaller canoes for outriggers) and put a big ole viking square sail on it. I'll stick to using it when the wind is right. Not a lot of room to tack on the river.

Just playing with ideas now but something will click one of these days.

Thanks all,

Happy new year

[whb]

Hi All,

Here's the problem. The boat will be used mostly on the Red Deer river in Alberta. It goes from being a class 4-5 whitewater river in the spring to an extremely shallow slow river in the late summer fall.

I have been trying to design a boat with a 4" draft but will likely have to go deeper to get the carrying capacity I want.

I had considered putting a tunnel in the bottom with a 4 stroke jet outboard at the end. This would actually sit 1/2 inch above the bottom of the boat.

This solution works and is common for the aluminum hunting/work boats used on shallow water.

However, the 4 stroke jets are way more expensive than what I want to do right now.

Our prevailing wind is either straight upriver or straight downriver. I'm tempted to build a flat bottom trimaran (Essentially a large canoe with smaller canoes for outriggers) and put a big ole viking square sail on it. I'll stick to using it when the wind is right. Not a lot of room to tack on the river.

Just playing with ideas now but something will click one of these days.

Thanks all,

Happy new year

[blisspacket]

Carl, I tend to agree with your assessment. My experience: 18' Pearson Packet launch, with a MinnKota 101lb thrust motor incorporated into the rudder. Six deep cycle batteries tapped for 36volts, 230 amp/hours. I enjoyed a six hour 21mile race from the Wye River Yacht Club, and the last five miles wind and wave were against us. We limped in on our own power with the volts reading 18. Personally, I like the idea of a Honda or Westerbeke portable generator to carry along.

Another point: Xantrex makes the Emeter, which is like the gas gauge and trip computer on your Caddie. For $200 it tells you how much juice you have left (based on present rate of consumption). What it doesn't tell you is how strong the headwind pipes up in ten minutes....

That said, my own lovehate relationship centers on the quiet power and the offtheshelf economy of MinnKota motors, and the eminently social environment you have in an electric boat. It's like a fondue dinner, time is spent slowly dining and conversing, versus rushhour at McDonalds and the Tourbus just pulled up with an outboard buzzermotor

[blisspacket]

Carl, I tend to agree with your assessment. My experience: 18' Pearson Packet launch, with a MinnKota 101lb thrust motor incorporated into the rudder. Six deep cycle batteries tapped for 36volts, 230 amp/hours. I enjoyed a six hour 21mile race from the Wye River Yacht Club, and the last five miles wind and wave were against us. We limped in on our own power with the volts reading 18. Personally, I like the idea of a Honda or Westerbeke portable generator to carry along.

Another point: Xantrex makes the Emeter, which is like the gas gauge and trip computer on your Caddie. For $200 it tells you how much juice you have left (based on present rate of consumption). What it doesn't tell you is how strong the headwind pipes up in ten minutes....

That said, my own lovehate relationship centers on the quiet power and the offtheshelf economy of MinnKota motors, and the eminently social environment you have in an electric boat. It's like a fondue dinner, time is spent slowly dining and conversing, versus rushhour at McDonalds and the Tourbus just pulled up with an outboard buzzermotor

[blisspacket]

Carl, I tend to agree with your assessment. My experience: 18' Pearson Packet launch, with a MinnKota 101lb thrust motor incorporated into the rudder. Six deep cycle batteries tapped for 36volts, 230 amp/hours. I enjoyed a six hour 21mile race from the Wye River Yacht Club, and the last five miles wind and wave were against us. We limped in on our own power with the volts reading 18. Personally, I like the idea of a Honda or Westerbeke portable generator to carry along.

Another point: Xantrex makes the Emeter, which is like the gas gauge and trip computer on your Caddie. For $200 it tells you how much juice you have left (based on present rate of consumption). What it doesn't tell you is how strong the headwind pipes up in ten minutes....

That said, my own lovehate relationship centers on the quiet power and the offtheshelf economy of MinnKota motors, and the eminently social environment you have in an electric boat. It's like a fondue dinner, time is spent slowly dining and conversing, versus rushhour at McDonalds and the Tourbus just pulled up with an outboard buzzermotor

[Kermit]

Looks like the Electric Wheel has great promise. With fuel cell, solar, and wind power developments, it can definitely work as aux power for many sailing vessels. I noticed a lot of these craft carry gensets anyhooo. Maybe a hybrid in the works? Whozit that is developing the hybrid motorcycle that is using a tiny diesel to make the electrons? Interesting stuff is coming below decks.

Ah, here it is. Have a look at this diesel engine!

http://www.ecycle.com/powersports/hybrid.htm

[This message has been edited by Kermit (edited 01-03-2002).]

[Kermit]

Looks like the Electric Wheel has great promise. With fuel cell, solar, and wind power developments, it can definitely work as aux power for many sailing vessels. I noticed a lot of these craft carry gensets anyhooo. Maybe a hybrid in the works? Whozit that is developing the hybrid motorcycle that is using a tiny diesel to make the electrons? Interesting stuff is coming below decks.

Ah, here it is. Have a look at this diesel engine!

http://www.ecycle.com/powersports/hybrid.htm

[This message has been edited by Kermit (edited 01-03-2002).]

[Kermit]

Looks like the Electric Wheel has great promise. With fuel cell, solar, and wind power developments, it can definitely work as aux power for many sailing vessels. I noticed a lot of these craft carry gensets anyhooo. Maybe a hybrid in the works? Whozit that is developing the hybrid motorcycle that is using a tiny diesel to make the electrons? Interesting stuff is coming below decks.

Ah, here it is. Have a look at this diesel engine!

http://www.ecycle.com/powersports/hybrid.htm

[This message has been edited by Kermit (edited 01-03-2002).]

[whb]

Blisspacket

I've looked at the MinnKota's roughly what hp does the 110 lb electric equate to?

I can't get a mental handle on pounds of thrust.

Thanks,

Howard

[whb]

Blisspacket

I've looked at the MinnKota's roughly what hp does the 110 lb electric equate to?

I can't get a mental handle on pounds of thrust.

Thanks,

Howard

[whb]

Blisspacket

I've looked at the MinnKota's roughly what hp does the 110 lb electric equate to?

I can't get a mental handle on pounds of thrust.

Thanks,

Howard

[blisspacket]

The MK 101 is a 36volt unit, and will draw as much as 33 amps. V x A / 750 = HP as defined by Alexander Watt, I think, which puts the MK 101 at about 1.5 HP.

HOWEVER: British Seagull folk just before they bellied up were bragging that their 8HP outboard produced 170 lbs of thrust.

Looking at the performance I enjoyed with the MK on an 18' Packet displacing about 1600 lbs, I'd say the MK was equivalent to a 2HP motor. I'm a bit puzzled by B.Seagulls numbers.

[blisspacket]

The MK 101 is a 36volt unit, and will draw as much as 33 amps. V x A / 750 = HP as defined by Alexander Watt, I think, which puts the MK 101 at about 1.5 HP.

HOWEVER: British Seagull folk just before they bellied up were bragging that their 8HP outboard produced 170 lbs of thrust.

Looking at the performance I enjoyed with the MK on an 18' Packet displacing about 1600 lbs, I'd say the MK was equivalent to a 2HP motor. I'm a bit puzzled by B.Seagulls numbers.

[blisspacket]

The MK 101 is a 36volt unit, and will draw as much as 33 amps. V x A / 750 = HP as defined by Alexander Watt, I think, which puts the MK 101 at about 1.5 HP.

HOWEVER: British Seagull folk just before they bellied up were bragging that their 8HP outboard produced 170 lbs of thrust.

Looking at the performance I enjoyed with the MK on an 18' Packet displacing about 1600 lbs, I'd say the MK was equivalent to a 2HP motor. I'm a bit puzzled by B.Seagulls numbers.

[rodcross]

I just happened to be flipping through a catalog put out by Vetus den Ouden Co.
http://www.vetus.com/
and they have a complete water cooled marine electric propulsion package for sale. I'm sure the price is astronomical, but it sure looks like a nice tidy package.

[rodcross]

I just happened to be flipping through a catalog put out by Vetus den Ouden Co.
http://www.vetus.com/
and they have a complete water cooled marine electric propulsion package for sale. I'm sure the price is astronomical, but it sure looks like a nice tidy package.

[rodcross]

I just happened to be flipping through a catalog put out by Vetus den Ouden Co.
http://www.vetus.com/
and they have a complete water cooled marine electric propulsion package for sale. I'm sure the price is astronomical, but it sure looks like a nice tidy package.

[wcralle1]

Frank
I to am planning to go with electric propulsion for the 22’ sailboat I am building.

I am impressed by your background in the battery industry, and so am taking your advise to heart.

It seams like you’re examples are using the worst-case numbers when considering if electric propulsion is feasible.

For instance, hull speed is the maximum realistic speed attainable with a small horsepower motor. In my case, hull speed for my boat is 6.16 knots. I have calculated that 3.5 h.p. Will move this boat (1800 lbs) at hull speed.
However if I shoot for 5 knots, I only need 2 h.p.
And 4 knots, I only need 1 h.p.

I can be happy silently gliding around at 4 knots all day long.
Also at the lower amp draw, the batteries will supply power for longer. Battery discharge is not a linier thing. Correct me if I am wrong, and I don’t have the figures in front of me, but it goes something like this. A battery can give say 100 amp hours at an 8 hour discharge rate, but at a 4 hour rate it only gives 80 amp hours. You loose power because you are trying to draw it out faster.

So slow down for your regular cruising. Save the high amp speed for when you get into a pinch. And think ahead. Don’t motor half the day down stream or down wind, then expect motor back with the other half of your battery bank.

Also it is not correct to equate gas h.p to electric h.p. by this I mean that a boat requiring a 9.9 h.p gas outboard, could probably get by with a 3 h.p. electric motor. This has something to do with the way gas outboards are rated. The 9.9 h.p rating is at the motor at a specific and high rpm. Not counting transmission losses, and the fact that most actual motoring is no ware near the rpm that theoretically produced 9.9 h.p.
With electric 60 pounds of thrust is about 1 h.p. Requiring aprox 746 WATS to produce.

I don’t know if blispacket is talking about a sail boat of not, but in my case the designer calls for 400 lbs of ballast, So I am using 400 lbs of batteries.

Fair winds
William

[wcralle1]

Frank
I to am planning to go with electric propulsion for the 22’ sailboat I am building.

I am impressed by your background in the battery industry, and so am taking your advise to heart.

It seams like you’re examples are using the worst-case numbers when considering if electric propulsion is feasible.

For instance, hull speed is the maximum realistic speed attainable with a small horsepower motor. In my case, hull speed for my boat is 6.16 knots. I have calculated that 3.5 h.p. Will move this boat (1800 lbs) at hull speed.
However if I shoot for 5 knots, I only need 2 h.p.
And 4 knots, I only need 1 h.p.

I can be happy silently gliding around at 4 knots all day long.
Also at the lower amp draw, the batteries will supply power for longer. Battery discharge is not a linier thing. Correct me if I am wrong, and I don’t have the figures in front of me, but it goes something like this. A battery can give say 100 amp hours at an 8 hour discharge rate, but at a 4 hour rate it only gives 80 amp hours. You loose power because you are trying to draw it out faster.

So slow down for your regular cruising. Save the high amp speed for when you get into a pinch. And think ahead. Don’t motor half the day down stream or down wind, then expect motor back with the other half of your battery bank.

Also it is not correct to equate gas h.p to electric h.p. by this I mean that a boat requiring a 9.9 h.p gas outboard, could probably get by with a 3 h.p. electric motor. This has something to do with the way gas outboards are rated. The 9.9 h.p rating is at the motor at a specific and high rpm. Not counting transmission losses, and the fact that most actual motoring is no ware near the rpm that theoretically produced 9.9 h.p.
With electric 60 pounds of thrust is about 1 h.p. Requiring aprox 746 WATS to produce.

I don’t know if blispacket is talking about a sail boat of not, but in my case the designer calls for 400 lbs of ballast, So I am using 400 lbs of batteries.

Fair winds
William

[wcralle1]

Frank
I to am planning to go with electric propulsion for the 22’ sailboat I am building.

I am impressed by your background in the battery industry, and so am taking your advise to heart.

It seams like you’re examples are using the worst-case numbers when considering if electric propulsion is feasible.

For instance, hull speed is the maximum realistic speed attainable with a small horsepower motor. In my case, hull speed for my boat is 6.16 knots. I have calculated that 3.5 h.p. Will move this boat (1800 lbs) at hull speed.
However if I shoot for 5 knots, I only need 2 h.p.
And 4 knots, I only need 1 h.p.

I can be happy silently gliding around at 4 knots all day long.
Also at the lower amp draw, the batteries will supply power for longer. Battery discharge is not a linier thing. Correct me if I am wrong, and I don’t have the figures in front of me, but it goes something like this. A battery can give say 100 amp hours at an 8 hour discharge rate, but at a 4 hour rate it only gives 80 amp hours. You loose power because you are trying to draw it out faster.

So slow down for your regular cruising. Save the high amp speed for when you get into a pinch. And think ahead. Don’t motor half the day down stream or down wind, then expect motor back with the other half of your battery bank.

Also it is not correct to equate gas h.p to electric h.p. by this I mean that a boat requiring a 9.9 h.p gas outboard, could probably get by with a 3 h.p. electric motor. This has something to do with the way gas outboards are rated. The 9.9 h.p rating is at the motor at a specific and high rpm. Not counting transmission losses, and the fact that most actual motoring is no ware near the rpm that theoretically produced 9.9 h.p.
With electric 60 pounds of thrust is about 1 h.p. Requiring aprox 746 WATS to produce.

I don’t know if blispacket is talking about a sail boat of not, but in my case the designer calls for 400 lbs of ballast, So I am using 400 lbs of batteries.

Fair winds
William

[Frank Wentzel]

William,

As long as you can achieve a battery placement scheme that gives you the righting moment and fore & aft center-of-gravity required for your design you should be ok. This requirement often places the batteries in the most useful area of the boat, but that depends on the design and your personal space requirements.

The 400lb ballast requirement conforms well with a battery-bank of six golf-cart batteries. Using EV105s, at a 21 amp discharge rate (one hp), and limiting yourself to a 50% DOD, you will have on the order of four hours cruising time. When needed, full DOD will give you about seven hours.

Having only one horsepower available means you are not going to be able to fight your way back home into a nasty head sea, but if your schedule is flexible, that becomes less of an issue. In addition, a sailboat is less likely to get in an true emergency situation since the wind is your primary power source (and, of course, we ragbaggers are better seamen http://media5.hypernet.com/~dick/ubb/biggrin.gif ).

You are right about the horsepower comparison between motor types. I would guess that the effective output of an outboard is the most overstated, mostly because of the inefficiency of small high-speed props. However, I think electric trolling-motors also have much the same problem. A large, low-speed prop either on an inboard engine or inboard electric motor is much more efficient. Also, most gasoline engines are designed to run at 1/2 to 3/4 throttle, whereas electric motors are routinely run at almost full rated output.

If you do go the electric route, please keep us informed. There seems to be a lot of interest in this area but a limited amount of real first-hand experience.


[This message has been edited by Frank Wentzel (edited 01-27-2002).]

[Frank Wentzel]

William,

As long as you can achieve a battery placement scheme that gives you the righting moment and fore & aft center-of-gravity required for your design you should be ok. This requirement often places the batteries in the most useful area of the boat, but that depends on the design and your personal space requirements.

The 400lb ballast requirement conforms well with a battery-bank of six golf-cart batteries. Using EV105s, at a 21 amp discharge rate (one hp), and limiting yourself to a 50% DOD, you will have on the order of four hours cruising time. When needed, full DOD will give you about seven hours.

Having only one horsepower available means you are not going to be able to fight your way back home into a nasty head sea, but if your schedule is flexible, that becomes less of an issue. In addition, a sailboat is less likely to get in an true emergency situation since the wind is your primary power source (and, of course, we ragbaggers are better seamen http://media5.hypernet.com/~dick/ubb/biggrin.gif ).

You are right about the horsepower comparison between motor types. I would guess that the effective output of an outboard is the most overstated, mostly because of the inefficiency of small high-speed props. However, I think electric trolling-motors also have much the same problem. A large, low-speed prop either on an inboard engine or inboard electric motor is much more efficient. Also, most gasoline engines are designed to run at 1/2 to 3/4 throttle, whereas electric motors are routinely run at almost full rated output.

If you do go the electric route, please keep us informed. There seems to be a lot of interest in this area but a limited amount of real first-hand experience.


[This message has been edited by Frank Wentzel (edited 01-27-2002).]

[Frank Wentzel]

William,

As long as you can achieve a battery placement scheme that gives you the righting moment and fore & aft center-of-gravity required for your design you should be ok. This requirement often places the batteries in the most useful area of the boat, but that depends on the design and your personal space requirements.

The 400lb ballast requirement conforms well with a battery-bank of six golf-cart batteries. Using EV105s, at a 21 amp discharge rate (one hp), and limiting yourself to a 50% DOD, you will have on the order of four hours cruising time. When needed, full DOD will give you about seven hours.

Having only one horsepower available means you are not going to be able to fight your way back home into a nasty head sea, but if your schedule is flexible, that becomes less of an issue. In addition, a sailboat is less likely to get in an true emergency situation since the wind is your primary power source (and, of course, we ragbaggers are better seamen http://media5.hypernet.com/~dick/ubb/biggrin.gif ).

You are right about the horsepower comparison between motor types. I would guess that the effective output of an outboard is the most overstated, mostly because of the inefficiency of small high-speed props. However, I think electric trolling-motors also have much the same problem. A large, low-speed prop either on an inboard engine or inboard electric motor is much more efficient. Also, most gasoline engines are designed to run at 1/2 to 3/4 throttle, whereas electric motors are routinely run at almost full rated output.

If you do go the electric route, please keep us informed. There seems to be a lot of interest in this area but a limited amount of real first-hand experience.


[This message has been edited by Frank Wentzel (edited 01-27-2002).]

[WWheeler]

I'm reviving this thread because I'm curious about the practicality and mechanics of a propeller mounted trolling motor as a sailboat auxiliary. Devlin's Nancy's China DC also shows this configuation.

- how do you mount it?
- what about generator backup?

[WWheeler]

I'm reviving this thread because I'm curious about the practicality and mechanics of a propeller mounted trolling motor as a sailboat auxiliary. Devlin's Nancy's China DC also shows this configuation.

- how do you mount it?
- what about generator backup?

[WWheeler]

I'm reviving this thread because I'm curious about the practicality and mechanics of a propeller mounted trolling motor as a sailboat auxiliary. Devlin's Nancy's China DC also shows this configuation.

- how do you mount it?
- what about generator backup?

[MarkC]

From my research, check out these European electric motor companies - (seems that many of the European lakes don't allow diesel/petrol motors)-

www.kraeutler.at (http://www.kraeutler.at) - Austrian company providing sail drive, outboards, outbord type arms, flange under water mounted, and complete in-board systems (motor,mount,shaft,prop)- products seem a bit more substantial than the Vetus offering.

www.asmomarine.com (http://www.asmomarine.com) - Danish company supplying full inboard systems

Import Duty or taxes might be an issue though.

Or a decent list on the boatdesign.net site;

http://boatdesign.net/Directory/Propulsion/Electric/

Cheers - Mark

[MarkC]

From my research, check out these European electric motor companies - (seems that many of the European lakes don't allow diesel/petrol motors)-

www.kraeutler.at (http://www.kraeutler.at) - Austrian company providing sail drive, outboards, outbord type arms, flange under water mounted, and complete in-board systems (motor,mount,shaft,prop)- products seem a bit more substantial than the Vetus offering.

www.asmomarine.com (http://www.asmomarine.com) - Danish company supplying full inboard systems

Import Duty or taxes might be an issue though.

Or a decent list on the boatdesign.net site;

http://boatdesign.net/Directory/Propulsion/Electric/

Cheers - Mark

[MarkC]

From my research, check out these European electric motor companies - (seems that many of the European lakes don't allow diesel/petrol motors)-

www.kraeutler.at (http://www.kraeutler.at) - Austrian company providing sail drive, outboards, outbord type arms, flange under water mounted, and complete in-board systems (motor,mount,shaft,prop)- products seem a bit more substantial than the Vetus offering.

www.asmomarine.com (http://www.asmomarine.com) - Danish company supplying full inboard systems

Import Duty or taxes might be an issue though.

Or a decent list on the boatdesign.net site;

http://boatdesign.net/Directory/Propulsion/Electric/

Cheers - Mark

[MarkC]

And I forgot Öco-Sachs GmbH at www.oecosachs.de (http://www.oecosachs.de) Their web-site is in German but click on these on the front page;

Außenborder
Wellenanlage
Elektroboote
Solarboote Ladegeräte
Stromversorgung Elektroantrieb
Steuerungen

You will see a list of the electric boats they sell and a great discussion of 'what connects to what' - including their diagrams under hybridsystem of using the Honda 1kw connected to the loader,battery, display etc. they offer an outboard and an inboard with lynch motor.

Going back to the Kräutler company - they offer up to 30kw power. I dont think that with the options of power offered, that battling the tide is an issue any more. It seems only the Solomon is more powerful but the Kräutler may be cheaper?? Check your import duties though!

Again - Cheers - Mark

[MarkC]

And I forgot Öco-Sachs GmbH at www.oecosachs.de (http://www.oecosachs.de) Their web-site is in German but click on these on the front page;

Außenborder
Wellenanlage
Elektroboote
Solarboote Ladegeräte
Stromversorgung Elektroantrieb
Steuerungen

You will see a list of the electric boats they sell and a great discussion of 'what connects to what' - including their diagrams under hybridsystem of using the Honda 1kw connected to the loader,battery, display etc. they offer an outboard and an inboard with lynch motor.

Going back to the Kräutler company - they offer up to 30kw power. I dont think that with the options of power offered, that battling the tide is an issue any more. It seems only the Solomon is more powerful but the Kräutler may be cheaper?? Check your import duties though!

Again - Cheers - Mark

[MarkC]

And I forgot Öco-Sachs GmbH at www.oecosachs.de (http://www.oecosachs.de) Their web-site is in German but click on these on the front page;

Außenborder
Wellenanlage
Elektroboote
Solarboote Ladegeräte
Stromversorgung Elektroantrieb
Steuerungen

You will see a list of the electric boats they sell and a great discussion of 'what connects to what' - including their diagrams under hybridsystem of using the Honda 1kw connected to the loader,battery, display etc. they offer an outboard and an inboard with lynch motor.

Going back to the Kräutler company - they offer up to 30kw power. I dont think that with the options of power offered, that battling the tide is an issue any more. It seems only the Solomon is more powerful but the Kräutler may be cheaper?? Check your import duties though!

Again - Cheers - Mark

[John Blazy]

I never knew that there was an elctric power thread on here. I've been into e-power for a little while (small scale), but also wood boatbuilding, and the two don't mix very often. I've researched extensively on electric boat forum (http://www.eboat.org) for the past year and was almost going to go direct drive with the Briggs & Stratton E-tek motor from EV parts (http://www.evparts.com) with the controller package for about 500 bucks and build the rest - stuffing box, shaft log, machining the shaft, etc. but someone at the e-forum said it might too overpowered for a 14' hull which I always wondered. So now I'm going with this arrangement:
http://www.imagestation.com/picture/sraid54/p275e874de93b1f36b240124d29d166c2/fc863ab1.jpg
and plan to use a chain linkage with nylon gears instead of the pulley/belt idea. After thinking this through, this is without question the simplest and cheapest electric arrangement one can do given the power output. This eliminates the costly, risky and time-consuming fabrication of the inboard shaft fittings, the rudder, and most importantly, the prop. You cannot buy off-the-shelf displacement hull (large DIA, low rpm) props designed and tuned for small boats at this power rating. This is why you can buy entire power systems from Elco, or Ray Electric Outboards for proper props but will pay multi-thousands. Well worth it - they are well made units - if you have the money.
For 500 bucks for MK Maxximm and seals and gears from McMaster Carr, I'm in business with a power supply that should push 14' to hull speed.

It sounds like you are asking about rudder installation. If you have existing rudder, you would have to cut the shaft off the TM, silicone seal a plug around the wires, run wires through hull or above WL, and cut/fit/glass the TM into the rudder - real simple.

I will look into a small generator too for emergency or auxilliary speed. Need to get an adapter to 24V output to wire the TM directly. Anyone done this or know of generators that output 24V?

See my link below for skeg-pivot explanation.

[John Blazy]

I never knew that there was an elctric power thread on here. I've been into e-power for a little while (small scale), but also wood boatbuilding, and the two don't mix very often. I've researched extensively on electric boat forum (http://www.eboat.org) for the past year and was almost going to go direct drive with the Briggs & Stratton E-tek motor from EV parts (http://www.evparts.com) with the controller package for about 500 bucks and build the rest - stuffing box, shaft log, machining the shaft, etc. but someone at the e-forum said it might too overpowered for a 14' hull which I always wondered. So now I'm going with this arrangement:
http://www.imagestation.com/picture/sraid54/p275e874de93b1f36b240124d29d166c2/fc863ab1.jpg
and plan to use a chain linkage with nylon gears instead of the pulley/belt idea. After thinking this through, this is without question the simplest and cheapest electric arrangement one can do given the power output. This eliminates the costly, risky and time-consuming fabrication of the inboard shaft fittings, the rudder, and most importantly, the prop. You cannot buy off-the-shelf displacement hull (large DIA, low rpm) props designed and tuned for small boats at this power rating. This is why you can buy entire power systems from Elco, or Ray Electric Outboards for proper props but will pay multi-thousands. Well worth it - they are well made units - if you have the money.
For 500 bucks for MK Maxximm and seals and gears from McMaster Carr, I'm in business with a power supply that should push 14' to hull speed.

It sounds like you are asking about rudder installation. If you have existing rudder, you would have to cut the shaft off the TM, silicone seal a plug around the wires, run wires through hull or above WL, and cut/fit/glass the TM into the rudder - real simple.

I will look into a small generator too for emergency or auxilliary speed. Need to get an adapter to 24V output to wire the TM directly. Anyone done this or know of generators that output 24V?

See my link below for skeg-pivot explanation.

[John Blazy]

I never knew that there was an elctric power thread on here. I've been into e-power for a little while (small scale), but also wood boatbuilding, and the two don't mix very often. I've researched extensively on electric boat forum (http://www.eboat.org) for the past year and was almost going to go direct drive with the Briggs & Stratton E-tek motor from EV parts (http://www.evparts.com) with the controller package for about 500 bucks and build the rest - stuffing box, shaft log, machining the shaft, etc. but someone at the e-forum said it might too overpowered for a 14' hull which I always wondered. So now I'm going with this arrangement:
http://www.imagestation.com/picture/sraid54/p275e874de93b1f36b240124d29d166c2/fc863ab1.jpg
and plan to use a chain linkage with nylon gears instead of the pulley/belt idea. After thinking this through, this is without question the simplest and cheapest electric arrangement one can do given the power output. This eliminates the costly, risky and time-consuming fabrication of the inboard shaft fittings, the rudder, and most importantly, the prop. You cannot buy off-the-shelf displacement hull (large DIA, low rpm) props designed and tuned for small boats at this power rating. This is why you can buy entire power systems from Elco, or Ray Electric Outboards for proper props but will pay multi-thousands. Well worth it - they are well made units - if you have the money.
For 500 bucks for MK Maxximm and seals and gears from McMaster Carr, I'm in business with a power supply that should push 14' to hull speed.

It sounds like you are asking about rudder installation. If you have existing rudder, you would have to cut the shaft off the TM, silicone seal a plug around the wires, run wires through hull or above WL, and cut/fit/glass the TM into the rudder - real simple.

I will look into a small generator too for emergency or auxilliary speed. Need to get an adapter to 24V output to wire the TM directly. Anyone done this or know of generators that output 24V?

See my link below for skeg-pivot explanation.

[WWheeler]

Mark: Thanks for the information. So far, I've had a chance to look at Krautler, and it seems to be extremely serious, and with an excellent range of systems inboard/saildrive etc. Duties shouldn't not be a problem, but exchange rates might! Also the use of Honda generator is a great idea.

John: Looks like a great project you've got there. So, I could pick up a trolling motor and re-engineer it to mount on the rudder. I think Bolger had a similar concept for several of his designs.

[ 03-25-2003, 11:49 AM: Message edited by: WWheeler ]

[WWheeler]

Mark: Thanks for the information. So far, I've had a chance to look at Krautler, and it seems to be extremely serious, and with an excellent range of systems inboard/saildrive etc. Duties shouldn't not be a problem, but exchange rates might! Also the use of Honda generator is a great idea.

John: Looks like a great project you've got there. So, I could pick up a trolling motor and re-engineer it to mount on the rudder. I think Bolger had a similar concept for several of his designs.

[ 03-25-2003, 11:49 AM: Message edited by: WWheeler ]

[WWheeler]

Mark: Thanks for the information. So far, I've had a chance to look at Krautler, and it seems to be extremely serious, and with an excellent range of systems inboard/saildrive etc. Duties shouldn't not be a problem, but exchange rates might! Also the use of Honda generator is a great idea.

John: Looks like a great project you've got there. So, I could pick up a trolling motor and re-engineer it to mount on the rudder. I think Bolger had a similar concept for several of his designs.

[ 03-25-2003, 11:49 AM: Message edited by: WWheeler ]