which battery?

[wharfrat]

I have a 22-foot sailboat, I intend to auxiliary power it with a 9.9 four stroke with electric start and I would appreciate some help on a battery. I will be running the standard masthead light, port, and stb. and aft running lights, anchor light, stereo, vhf, and depth sounder. I plan on doing a fair bit of gunkholing so I will probably be running the anchor light and stereo at night and listening to the weather station on the vhf.

My question is should I buy a cranking battery, deep cycle or dual-purpose battery. I don’t know what the kicker amp charging capacity will be. If I buy both cranking and deep cycle how do I wire it so the deep cycle will be charged by the kicker also?

Thanks to all who are kind enough to reply.

[Donn]

I don't know what your budget is, but I'd buy an Optima deep-cycle battery. It can be mounted in any position, including upside down. It requires no maintenance. It will crank your motor and run your lights, and even some electronics if you wish.

[Peter Malcolm Jardine]

I would also suggest Surrette batteries .. Canadian... from the east coast...I put in a serious 12 volt system with two 300 amp hour batteries in a trawler.. works awesome. They make a large number of batteries for boats, heavy equipment, and solar and wind power systems. If you can, use two six volt batteries.. will give you more reserve. www.surrette.com (http://www.surrette.com)

[wharfrat]

Thanks Donn
I'll see if that type is available out here. Would a 9.9 have enough charging output to bring that battery back to full charge? Is that an acid or gel or AGM?

[wharfrat]

Thanks Peter I'm checking their site out now

[Donn]

I don't know where "out here" is, but Optimas are available on the web. Surrette is also a great name in marine batteries....they own the Rolls name, 2 of which grace the bilges of Loon. 6 years old, and cranking like they were kids....but they're heavy buggers. I imagine a small sailboat could call them ballast.

[Peter Malcolm Jardine]

you bet Donn... the two batteries I put in that Trawler (my fathers) were about 240 each hehehe We put a 190 amp alternator in as well and isolated the lighting back.. Two years cruising in the Bahamas, and not a single problem.. I think they do make a small six volt battery as well..

[Gary Bergman]

I'd go with a spiral cell battery,deep. They charge like acid, don't take you to the cleaners. My boat is 38' with double banks, and 8D's, but there is a spiral cell 'hid' in there for emergencies..

[rodcross]

Wharfrat, you really have to know what that kicker is going to be able to put out in amps in order to size the battery properly. Deep cycle is certainly right, although I might not go straight to the Optima as there are not many size selections. Any AGM deep cycle, spiral or not, is the best choice, in my humble opinion. I might just add a solar panel to supplement the charging. Sailing at night with the music on is going to tax any battery that engine could charge.

[imported_Conrad]

Definitely deep cycle, so it won't go bad if it has the opportunity (and it will) to completely discharge. Your kicker doesn't need the higher output capability of a starting battery.

Also, since most outboards have alternators that put out a max of about 10-15 amps you're limited in the size of battery you can operate efficiently. I would suggest a group 30 deep cycle which will give you about 120 amp hours, with 60 usable being a good rule of thumb. A standard lead acid wet cell will cost about $60-80 at a battery supply house. This will give you ten hours of 6 amp draw, enough to run the cabin lights, stereo, and anchor light overnight, and let you start the motor with the starter come morning. It will take about FIVE HOURS of run time to recharge with the kicker (efficiency drops off as full charge approaches) so you may want to look into some solar panels or additional alternatives. Realistically, if you purchase more capacity you'll have to hit the dock and plug in at a much higher charge rate.

For small boats, a more practical alternative is to look into some of the new high efficiency lighting (halogen and flouresent) or buy a couple of romantic oil lamps. ;) And ditch the high power amp and sub woofer for the stereo!

[ 12-11-2002, 02:20 AM: Message edited by: Conrad S. ]

[martin schulz]

Originally posted by wharfrat:
I will be running the standard masthead light, port, and stb. and aft running lights, anchor light, stereo, vhf, and depth sounder. Sailing a 24ft Gaff Cutter not as Daysailor but more for small cruises with a lot of anchoring I would recommend petroleum lamps for anchor-light. That way you don't waste electricity. Then, of course you will need a separate starter battery-you'll probably know that.

[Bruce Hooke]

What I think you really need to do is work up an overall energy 'plan' for this boat. Figure out how much power each device you want to run will need and estimate how long you will want to use each item under normal heavy-use conditions -- say when you are on a cruise. From this you can calculate how much power you will use each day. Then figure out how much charging output the engine will generate and therefore how long you will need to run it each day to keep up with your usage. From there you can get a reality check first off (if you will have to run your motor 5 hours/day to keep up with your consumption then some re-thinking is probably in order); and you can size your battery based on how long you want to be able to run the lights & other such stuff without needing to run the engine. Finally, check what the motor needs to start it and make sure the battery is rated to produce the necessary short-term burst output. Also, consider what you will do if you run down the battery to the point where it won't turn over the motor (does the motor have a manual start option?). This is a key reason why most boats with electric start motors choose to have two batteries - one for starting and one for accessories. Any decent book on marine wiring will explain how to wire such a system...

A deep cycle battery for the accessories is a must but on a small boat like this you can probably do fine with a deep cycle battery from somewhere like Sears. That's what we use on my father's boat and it does just fine. For a small system such as the one you are talking about I wouldn't bother with a super fancy deep-cycle battery that costs hundreds of dollars. FWIW - the battery on my father's boat is charged by a solar panel, which does fine at keeping up with our needs, but does require very efficient energy useage, and only allows for limited night sailing.

[rodcross]

Its a little off topic, but I installed a gizmo, at the beginning of the summer that has turned out to be a great way to simplify charging issues on the boat. When you have different types of batteries, i.e. deep cycle/starting , the problem has always been they require different charging regimens and since they should not be connected you have to remember to flip switches in order for both batteries to be properly charged. This gizmo was called an 'Echo Charger' which allows the alternator to be directly connected to the house battery without any switches. The Echo Charger then taps into the charging only when the starting battery needs it. Now, I turn the battery switch on at the beginning of the season and turn it off at the end. Nice! Really nice!

[Ian McColgin]

Don't over-engineer this project. The light use is small. Get something cheap on sale like a Sears DieHard.

In the mid '60's when I sailed the family Electra a lot with no motor at all, I just used a car battery for that sort of lighting. Lots of night sailing. When my voltmeter showed it was getting low, I'd drop the battery in the dink when I rowed home and put it on the trickle.

With the motor, you may recharge enough that you need not take it home, or you may sail so much that the short motor running time does not even fully recharge the start much less any lighting.

So what?

You can hand start the OB anyway and you can take the battery home for house charging.

The only realy trick is to watch the volts and not pull it down so far that you can't recharge. But if you do that, you're probably still in warranty and places like Sears honor it even when there's been blatant abuse.

G'luck

[Gary Bergman]

Well, back to what I said, Optima batteries(new kid on the marine block} are reasonable and fit generally everywhere. It ain't rocket sience,it's boats. Also, I dunno about where you live, but where I anchor, the Coast Guard frowns heavily on 'classic kero' in lieu of electricty. It's 2002.....

[Meerkat]

Originally posted by Gary Bergman:
Well, back to what I said, Optima batteries(new kid on the marine block} are reasonable and fit generally everywhere. It ain't rocket sience,it's boats. Also, I dunno about where you live, but where I anchor, the Coast Guard frowns heavily on 'classic kero' in lieu of electricty. It's 2002.....Gary your local CG can frown all they want, but kerosene running and anchor lights are legal per COLREGS and the CG's own publications as has been mentioned several times in other threads on the subject.

[Gary Bergman]

That's well and good, but just cuz it says so doesn't keep them from boarding you alla the time because you are not 'visible,' and leave you 'tellin' it to the judge! Not me but a friend....

[Ian McColgin]

I've lived with kero both interior and exterior illumination. It has its purpose but kero is harder to use and more expensive per hour of light.