Many hobbyists use these batteries to power electronics because they are affordable and easy to swap.
As Max probed the terminals, the story of the battery's "brain" began to unfold: The Power Couple (Positive & Negative) Hart 20v Battery Pinout Diagram
Some Hart batteries have only 4 physical terminals (missing T4). In that case, T2 remains the thermistor, T3 is the ID pin, and T4 is simply absent. Many hobbyists use these batteries to power electronics
: Located on one outer edge. This provides the primary 20V DC output to the tool. : Located on one outer edge
These additional internal contact points allow the charger to monitor the voltage of individual cells (typically around 4V increments: 4V, 8V, 12V, and 16V), ensuring they are evenly charged. Positive (+) and Negative (-): These provide the primary 20V power output for your tools. Safety & Diagnostic Features Under-Voltage Detection:
. This pin allows the charger or tool to sense if the battery is overheating during use or charging. ID (Identification): This pin communicates the battery type