I should have posted my test results back when I tested.

the circuit is an illusion, it makes you thing that the energy will be flowing from the higher voltage side to the low side.

if using 4 12 volt batteries then one would think that the the 2 batteries in series (24 volts) will charge the 2 batteries in parallel (12 volts) and this is in did true, but the total energy available in the 4 batteries will last the same time if wiring all 4 batteries in parallel to power a 12 volt circuit.

for example if you have a load that uses one amp at 12 volts.

when powering such load from this circuit, it will be drawing 1 AMP from the 24 volt batteries so 24 x 1 = 24 watts. and it will be charging the 2 batteries in parallel at 12 volts at one AMP = 12 watts.

so the 24 battery pack is draining at a rate of 24 watts

the 12 volt battery pack charging at a rate of 12 watts

and the load is using the other 12 watts.