First of all use a voltmetter to determine the output voltage of the unit while cranking. If the voltage is not enough you will need to open the unit to check if the induction in the system is faulty. Check the wires for continuity and also check the coils. Unless the coils are open you will not have any issues. Once the power is coming then you must check with the terminal for connection issues. I think you will be able to charge provided your charger is not defective. hope I could help? Good day