If you have a power supply that you can regular the volts and amps. Could this be used to charge 48v battery as long as you set to 52v. If so what amps should you set. And does the BMS have anything to do with over charging?
I don't see why not. Using Ohms law as long as the voltage is set to 52 the current shouldn't be excessive, I=E/R. You'll get better opinions than mine though.
