Solar Panels for 12 volts

[countrymno]

A 300 watt 36 volt panel, hooked up to a 12 volt battery, how many watts can you expect going to the battery, A 200 watt 24bvolt panel, hooked up to a 12 volt battery, how many watts can you expect going to the battery

[littleharbor]

You will get whatever amps it is putting out at the time, times the battery's voltage. If a 120 watt, 12 volt panel is putting out say 7 amps and the battery is at 13 5 volts you will get 94.5 watts into the battery. If a 300 watt 24 volt panel putting out 8.3 amps (Actual Vmp rating is around 36 volts) is connected a 12 volt battery sitting at 13.5 volts you will get 112.5 watts into the battery..

This is where an MPPT controller works so well. It takes all the power the panel is putting out and steps down the voltage, while boosting the current proportionately. PWM controller, current in = current out. MPPT, watts in = watts out..