two battery bank wiring

Discussion in 'The Projects Forum' started by ger32, Nov 7, 2010.

  1. ger32

    Thread Starter New Member

    Jul 5, 2010
    How do I set up two battery banks so that:
    1--I can charge each, separately, with my 120v battery charger and/or engine alternator and/or my solar panel?

    2--I can power my converter and other 12v devices from each bank, separately.

    3--I assume I would use a battey selector (isolater) switch. How would I wire everything. I have seen some very coplicted diagrams on marine sites that don't seem to help me.

    In other words--2 separate battery banks, charged by three sources
    and powering other separate devices.

    It would great if I could see a wiring diagram.

    (note: this was moved from Homework Help forum with some additions)
  2. magnethead


    Nov 9, 2010
    Why are you wanting to use 2 seperated batteries? The main problem here, is that the vehicle chassis is one big ground. The split battery system (see, most outboard boats) works because the negative cable must be ran, you don't ground to F/glass like you do steel. I think you would be better off having 2 batteries wired in parrallel. Our racecar has 2 optima red tops in parrallel, that's how most are. We tried running only one once, and it couldn't even spin the engine over.

    If you're looking to do a dual battery just so that you can sit and draw off one and leave the other for starting only, then yes, you'll want an isolator. They aren't very hard to actually install. Wiring everything to them is a little more tedious, especially if you want to be able to flip/flop the battery roles.
  3. retched

    AAC Fanatic!

    Dec 5, 2009
    Is this for an RV?

    If you are not dealing with a starter battery, you should not use 2 banks, but 1 large bank.

    This will increase your capacity. You can monitor your solar panel to only charge if there is enough voltage to charge. If the solar voltage output is less than 14.4 (If it is a 12v bank)then switch it out, and switch into another charging option.

    Measuring the voltage of the bank you can determine if you NEED a faster charge option or if a solar trickle will do.

    If your bank is more then 20% depleted, a generator or your 120v charger should be used because you are getting close to the 30% drained, life-altering percentage. ;)

    There are solar chargers that allow you to connect 120v and solar arrays to it.

    If solar is available, it charges with it. If NOT, it uses the 120v source.

    Hand-rolling a comparator or microcontrolled solution will only be cost effective if the size of your bank and solar array is small.