04-26-2010, 02:51 AM
If it is wired that way, the extra battery is doing nothing. And if you hook up the ground, you end up with 24 volts. You want it hooked up in a parallel circuit, which means you hook + to + and - to - .Any time you hook up + to - and have the first battery grounded and the second battery + to positive, you will have 24 volts and blow everything up.
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