how long does it take for a solar panel to start charging a battery
Most solar panels are 12 volt so use the same equation to find out how many amps the panel makes. 80W = 12V * X Amps 80/12 = 6.67 amps A 50 Amp Hour battery takes 50 hours to charge at 1 amp, 25 hours to charge at 2 amps, and 50/X hours to charge at X amps, just like the discharge calculation above.50/6.67=7.5 hours.ow most CFLs are 120 volts AC and not 12 volts DC like the battery, so I assume you have an inverter to make 120V AC power from the battery. The inverter will not be 100% efficient so the lights will last a little less than the full 23 hours.