Another battery charger question

[Concordia...41]

I've looked at several good sites on line and I read this thread:

http://www.woodenboatvb.com/vbulletin/upload/showthread.php?t=61396&highlight=battery+charger

So now that I have a basic comprehension of battery basics and/or am really confused, here is my situation:

It looks as if I will have two 4D Glass Mat batteries and a TBD* starting battery (To Be Determined ;)).

I probably wouldn't jump up and by two 4D Glass Mats, but they seem to have a lot of advantages and I have a deal working where when I leave the warehouse I am going to get the batteries for a couple of the shop tools that I don't need / don't have room for. :D

Dave bought Sarah a DualPro triple charger http://www.dualpro.com/ , and it is still in the box. But it looks like it is too small (22.5 amp total - 7.5 amp per battery). :(

Anyway, freezing temperatures are not a problem. My usage will be sporadic. She will be dock-kept and while not having shore power or a generator, I'll have AC through a permanent drop I plan to run down the Charlie Nobel. The engine came with an 80 amp alternator, so charging underway will not be an issue.

That leaves the the main concern being a triple charger that will get along with the glass mat and starter batteries and that will keep a healthy charge on the batteries when she sits at the dock for weeks without being used.

I'll go back and finish reading the links on the above thread.

Second miscellaneous question: Is there some reason I can't go with just one 4D battery? They are like really big, honking, heavy things?

Thanks for any advice/guidance anyone cares to offer.

- M

[carioca1232001]

..............

Dave bought Sarah a DualPro triple charger http://www.dualpro.com/ , and it is still in the box. But it looks like it is too small (22.5 amp total - 7.5 amp per battery). :(

Anyway, freezing temperatures are not a problem. My usage will be sporadic. She will be dock-kept and while not having shore power or a generator, I'll have AC through a permanent drop I plan to run down the Charlie Nobel. The engine came with an 80 amp alternator, so charging underway will not be an issue.

That leaves the the main concern being a triple charger that will get along with the glass mat and starter batteries and that will keep a healthy charge on the batteries when she sits at the dock for weeks without being used.

I'll go back and finish reading the links on the above thread............................................ ...........

Thanks for any advice/guidance anyone cares to offer.

- M

I´ll provide some input to your first query only.

The output currrent rating of the triple charger (3 x 7.5 Amps) seems perfectly adequate for the type of service envisaged, viz., sporadic use of boat.

For example, my current 5 Amp charger is able to replenish the charge of a 12 V, fully discharged lead-acid wet cell battery, of 120 Ampere-hour capacity, within about 12 hours.

Say, if you went out sailing daily and used the incandescent lighting and galley gear (fridge, microwave etc.) intensively, you may want to charge your house battery in, say, six hours on arrival at dock. A case for a more powerful charger.

As for the 80 Amp alternator on the engine, and if you do use the engine while underway as diesels are not happy working at light-load, as for instance, charging a battery only, you may consider retrofitting a BALMAR (or similar) excitation assembly to the alternator. In this manner, your alternator is modified to emulate an intelligent charger, similar to the DualPro you mention above, for around 200 bucks.

[redbopeep]

Hey, hope things are going good with you as you get the boat launched. Exactly which model do you have? They seem to have ones that are 15 amp/bank, 10 amp/bank, 4 amp/bank...many...

Its nice to have two battery banks -- you'll always have your starter battery even if you run down the house battery...

The 4D batteries are great but costly when considering AGM instead of flooded. We have one for the house bank and one that is the starter battery on our non-wood boat (a Rawson 30). Not that it will help you, but we have a XANTREX True Charge 40 on that boat. As I recall, it is a charger that can handle different kinds of batteries all at once--regular flooded battery in one bank and glass mat in another bank, for example (if you need that capability ever...). It seemed to do great charging with shore power at the marina. There's a nice little remote display that you can buy which shows the charging status of the two banks, as well. Now on a mooring, we're charging the batteries with a small 1.2 amp 18 watt solar panel, though. We just use the XANDREX "outlet" to plug in an inverter to run 120 V things right now. I think we bought it because we could move it to our larger boat and add more (and larger 8D) batteries to the banks...for just two batteries one could use the XANTREX True Charge 20.

http://www.westmarine.com/webapp/wcs/stores/servlet/producte/10001/-1/10001/29823/377%20710/0/XANTREX%20charger/Primary%20Search/mode%20matchallpartial/0/0?N=377%20710&Ne=0&Ntt=XANTREX%20charger&Ntk=Primary%20Search&Ntx=mode%20matchallpartial&Nao=0&Ns=0&keyword=XANTREX%20charger&isLTokenURL=true&storeNum=null&subdeptNum=null&classNum=null

[Frank Wentzel]

Hi Margo

You might consider using a bank of 6 volt golf-cart batteries instead of 4 or 8 D batteries. Much easier (and safer) to handle and cheaper per watt hour because of the high production volumes.

/// Frank ///

[Lew Barrett]

Another option is an inverter/charger. The better ones are very smart indeed when it comes to charging, and having AC can be handy. I like the golf cart batteries myself; you get a different profile installing those, but two good ones would probably whip 4 4Ds.
There's a lot of technology in battery chargers these days as you know. Three stage chargers are needed for AGMs but work well with flooded batteries to maximize their useful life and give a full discharge range. How did you decide to go AGM?

[TMny]

I tend to concur with Carioca , that:
>The output currrent rating of the triple charger (3 x 7.5 Amps) seems perfectly adequate for the type of service envisaged, viz., sporadic use of boat.

Rational decisionmaking begins with a determination of the load on the battery which indicates the capacity needed , being mindful that discharging very low seriously decreases the useful battery life.

Many boats have two battery banks for reliably starting when one batrtery is discharged; the starting battery is here sized for engine-starting , while the other depends upon its appliance/lighting load+time.

Attention to quality cabling/connections , and clean/corrosionfree connections pays off.

[Peter Malcolm Jardine]

First, there is no such thing as too much housebank in my opinion, Second, two 8D's is not a huge housebank anyway. Third, that charger is a little small. Look for and buy Nigel Calders book on Electrical... excellent guide, and has diesel engine troubleshooting too.With two 8D batteries, you will get roughly 500 amp hours of house bank. If you have refrigeration, lighting, a TV, etc... you will need it if you plan to stay put for a few days or so. A charger of the size you have would take a long time to charge up those 8D's if they were down 50%. Remember, buying chargers, batteries, and laying out wiring is about what you envision doing, and what you might envision doing, and what somewhat else who owns the boat later, or comes with you cruising might envision doing..:DIf I were buying a smaller charger, (40 amps or less) I would be looking at the PROMARINER line. Excellent quality, a five stage smart charger, and the ability TO CHARGE DIFFERENT SIZES OF BATTERIES WITH OUT OVERCHARGING. As for inverter chargers, the XANTREX Freedom line is a good inverter charger series. That said, it has been out for a couple of years, and is due for an update. Look to see a five stage charger, and a similiar circuit to Promariners for different battery sizes. Anything less than a 1000 watt inverter is a waste of time in my estimation. You want enough power to run some tools, a coffee maker, and a small microwave..(not all at once)Electrical systems on most sailboats in my opinion, are too small, chargers too light, and have no future expansion capabilities as a result. I have two 125 amp hour starting batteries, two 100 amp hour starting batteries, and a 75 amp hour generator battery on board, and my boat is an inland cruising boat. When I helped upgrade my fathers trawler for the caribbean, it had two 300 amp hour Surrettes, two 75 amp hour starting batteries, a 60 amp alternator for starting, and a 190 amp continuous alternator for house... on a manually adjustable rheostat. No air, and the stove was propane. Extra power is a good thing.