Batteries in Parallel

[MCahoon]

As you may know, a battery can supply huge amounts of current at a relatively fixed voltage. When you connect two batteries directly together, if there is any difference in the voltage, current will flow from the more fully charged battery to the discharged battery. Much current will flow, wires will heat, and a good likelihood of damaging one or both batteries (think internal impedance of the battery and the heat from the I^2 loss) and probable reduction of battery life due to the shedding of lead from plates of the batteries.

Would your application allow the approx 0.7 V loss due to a diode being put in series with each battery, such that the connection of the charged battery would effectively disconnect the discharged battery? The diodes would have to be selected to handle the load current (with a significant margin I would hope).