Reconfiguring my battery set-up

[KRB64]

This is on the '82 260DA

Right now I have two batteries on one bank and a single on the other. The single has nothing connected to it but the engine. The bank with two batteries power the fridge, the stereo and the bilge pump, plus the engine. I have a fairly new charger that maintains two banks seperately.

The way I've been running is to use the single for the engine and the doubles for the house when on the hook. We stay overnight and are very frugal with the juice. Mainly powers the fridge. Lights are used sparingly and they are LED, stereo is used only a little.

Two years ago the single went bad and I replaced it with one from my marine mechanic. What I just now realized (stupid me) is that it was a deep cycle. So now I think I am backwards. Shouldn't I have two deep cycles to power the house and one regular battery to start the engine?

Can I move one of the regulars to the single bank and the deep cycle to the two bank and buy another deep cycle or should both batteries in the two bank be the same age?

Thanks

 

[compensation]

You should not put a new and an old battery in the same bank. There is no reason the deep cylce won't work as a starting battery, not ideal, but not worth replacing.

Just replace the two in the house bank batteries with new deep cycles. You don't mention what size they are, but if they are group 27, your battery boxes may be big enough to accomodate group 31s which would give you incrementally more reserve capacity.

 

[Redhook98]

Deep Cycles as starting batteries are not bad. I have 4 batteries on my boat and all are deep cycle group 27's. As long as you have enough cold cranking amps to reliably start your motor, that is what really matters (IMO).

Do not ever put 2 in parallel that are of different age or type though. Your charger will read them differently and could over or under charge your batteries. If your going to put 2 in parallel and charge them that way, make sure they are the same type and age (i.e. new group 27 deep cycle). Mixing different groups, ages, and types (DC vs starting battery) is a no-no.

 

[StevenA]

I have two battery banks, my port two batteries run all the house current as well start the port engine. The starboard two batteries start the starboard engine as well as generator. Replaced all the original batteries at end of last season with "dual purpose" batteries. Went from the Group 24 to Group 27 that should have been in my boat from the start. If you have academy sports in your area you can usually get the dual purpose batteries (starting and deep cycle in one) for under $60 usd each. Love my setup and no battery issue problems.

 

[KRB64]

Great info guys, thanks.
They are group 27s @ 575 cca.
Whats academy sports? a store?
A dualpurpose battery is like a deep cell AND a regular one?

 

[StevenA]

Great info guys, thanks.
They are group 27s @ 575 cca.
Whats academy sports? a store?
A dualpurpose battery is like a deep cell AND a regular one?

Academy is a sporting goods store, here is a link to the batteries I and many of my friends run, and yes dual purpose serve as deepcycle and starting battery in one. These are great long lasting inexpensive ($59.95 reg price, ofter on sale) batteries. Check around your area for them.
http://tinyurl.com/dualpurposebattery

 

[KRB64]

I plan to recycle my existing batteries to our other boats. Then I'll get two new deep cycles for the house and one new regular for starting.

Still pondering on this and reading other posts. Now MORE questions:

Once I'm off shore power, should I not charge my deep cycles off the alternator? I read this in anther post. Do I need an isolator to be able to charge the deep cycles?

No way can we live off two deep cycles for a weekend or week without a recharge when we're motoring around.

Whats the advantage of an isolator if they are swithced? Doesn't that "isolate" them?