Feed PWM charge controller from DC power supply?

[lkruper]

Using two lower voltage chargers, you mean?
Yes, that can be done with the batteries still in series IF the charger outputs are isolated from the incoming power ground and the insulation between the internal electronics and the case can withstand the voltage. For two 12V chargers and a 24V bank I would expect it to be fine. For two 8 12V chargers and a 96V battery bank I would not be as optimistic.

If one side of the charger output is grounded I do not recommend trying to float the whole charger off ground to avoid a short circuit. It is theoretically possible, but a very bad idea.

Interesting. The reason I ask is that it might have implications for expanding a solar battery system. Not saying it wouldn't be better to size if properly first, but:

1) Two 6v golf cart batteries with a 12v charger and 12v inverter for a test system.
2) Double the above system.
3) Re-configure for 24 volts, putting one charger on each pair of 6v batteries.

(I realize I have deviated from the original question here with two 12v batteries in series, does that matter?)

Now I don't suppose that one could deploy the two inverters, one on each battery (or battery pair)? The reason I ask is that I don't understand why it works with the two battery chargers, one on each battery. If the voltage at one battery or battery pair is 12v, even in 24 series then on the face of it, the two 12v inverters should work as well?

From the post from midnight solar, it appeared that each 12v charger would fix an imbalances in one 12v battery in a 24v series bank. Even if my above nonsense does not work, that does appear to be an advantage in keeping batteries healthy in series.

Sorry for the rambling, but these new possibilities for configuration have my imagination running.

[lkruper]

Using two lower voltage chargers, you mean?
Yes, that can be done with the batteries still in series IF the charger outputs are isolated from the incoming power ground and the insulation between the internal electronics and the case can withstand the voltage. For two 12V chargers and a 24V bank I would expect it to be fine. For two 8 12V chargers and a 96V battery bank I would not be as optimistic.

If one side of the charger output is grounded I do not recommend trying to float the whole charger off ground to avoid a short circuit. It is theoretically possible, but a very bad idea.

This Deltran site shows series and parallel of batteries and chargers. -> http://www.batterytender.com/Connecting-Chargers/

And another -> http://www.iotaengineering.com/pplib...l_Charging.pdf