Yes, you can charge LANPWR LiFePO4 lithium batteries with solar panels. You should size your charge controller based on the voltage and current output of your solar array setup. That will ensure that your charge controller can process and regulate the power coming from your solar panels. Take a 24V MAX. 22 amps output solar system as an example, you need a solar charge controller that can handle 24 volts and 27.5 amps (125% of your max current output).