If you have a 48V battery like theWeize 48V100ah, what voltage must your solar panel be? How do you match these panels, batteries and charge controllers when they have different voltages? It can be confusing, but here we will simplify everything. The VOC (voltage open circuit) of your solar panel must be 1.4 to 1.8. Regardless of battery type, the solar panel voltage must always be greater than the battery. With a 48V battery, your solar panel voltage must be higher than 48 volts to produce a charge. By connecting solar panels in a series you can increase its voltage. Take 3 x 350W. The answer depends on how much power the solar panels have, how much sunlight is available, battery capacity and how fast you want to have the battery charged. A 100ah 48V battery holds. PWM and MPPT charge controllers have the same function, protect the battery from overloading, overcharging and otherwise keep it running the way it is suppose to. A 20A MPPT charge. The figures above are for fully charging a battery. If you are using a lead acid battery (FLA, gel, AGM), it is probably 50% filled. At least it should be because lead acid batteries should never be fully drained. Doing so shortens their life cycle. The 50% depth discharge is one of.