One big vs. several small batteries

[Pogue]

I've done a little searching and will do plenty more, I promise.

I have access to a large number of these. Wired in parallel, 2 groups of 7, I would get 98 amps(+/-).

Any downside I'm missing? If one fails the rest should at least get me home, correct?

Right now it'll simply run from the main battery to the isolator, battery banks, then inverter. Simple as possible. Kindly show me the error of my ways....

 

[DaveInDenver]

It's acceptable to make a bank from several batteries and if they're free then sure, nothing wrong with trying. Probably wouldn't set out in a new installation to use large banks of small batteries as opposed to a single of sufficient size if you can.

With that large of a bank it will hard to keep them balanced. Take time to research bank wiring best practices, such as this example found in a hasty Google image search.

 

[Pogue]

Ah, that makes sense. They are free and readily available so I may still try, maybe run non essentials off the smaller bank to make sure I don't accidentally kill my main power. But that gets me away from simplicity and I'm not bright enough to get fancy.
I'll have to look around and see if we have any more of the bigger batteries around, that would fix all issues.

Thanks!

 

[broncobowsher]

Free, go for it.
Biggest issue I have is when one cell goes that battery drops. All the other batteries discharge into that one bad battery trying to equalize. Turns into a self destruct sequence. Generally no more than 2 batteries are run in parallel.

 

[DaveInDenver]

The weakest one dictating the lifespan is the give-and-take of banks of anything, batteries, solar cells, etc. But this is a fundamental problem you can never escape as a battery itself is a bank of cells in series. Failure of one in this bank is generally immediately show stopping. So even if you have just one physical box with terminals it's already important to consider equalization and proper care and feeding. Putting two or 10 in parallel just introduces a new set of factors for design and use.

 

[beef tits]

By the time you purchase all the wiring, connectors, etc. you may be better off just getting a cheap lead acid deep cycle from Vato Zone. Last one I bought ran my Lance 815 just fine for two season with help of a solar setup. It was like $125.