Which is better - (3) 12v batteries vs (2) 6v batteries

Hi BFL13,

Mixing the 6 bank and 12 bank may result in some parasitic action between them. But under heavy loads (microwave, hot water heater), Peukert may give better results with them strapped together.

For "running the lights" until the "demand" is greater than the parasitic action, it would be better to keep them as individual banks.

The other factor is that, solar during most of the day, may cover that parasitic action between the banks.