WB400p Battery Reset

The battery died on me from being connected to the AD400pro for too long without being used. I left it for over 6 months in dead state, it still had 4 volts of charge after all that time. I had looked into buying a new battery but it would have been $200 CAD. I found other videos on how to perform a WB400p battery reset but most involved using a lab power supply. I wanted to do this fix as cheap as possible. I had to spend $25 dollars on a multimeter. I figured the power supply that comes with the AD400Pro gives the exact power delivery that would charge the battery safely.