The battery and charger use these pin connections to signal specific faults, such as "Temperature Out of Range" or "Over Current Detected," usually through flashing lights on the charger or battery fuel gauge. to build a DIY adapter troubleshoot a battery that isn't charging? Hart 20v Battery Pinout Wiring Diagram
Below is the complete pinout diagram for the standard (Models: HPLB01, HPLB02, HPLB04, etc.). Hart 20v Battery Pinout Diagram