Does the PWM OR MPPT solar controller give the highest efficiency when used to charge two very small 12 volt batteries in series for 24 volts? Each battery 1.2 amp hours.
My input to the solar controller will be 24 volts and not many amps
I am not worried about cost. Just the efficiency.
From what I can tell MPPT looks far superior. It is basically a digitally controlled and optimized DC to DC converter, so I would say it's just a smarter version of a typical PWM controller.
http://www.solar-electric.com/mppt-solar-charge-controllers.html/
HTH,
M@