The standard external connector on the battery pack includes the following primary pins: Positive (+)
: Identifies the battery to the tool or charger to ensure compatibility. C (Control)
When looking directly at the interface of a HART 20V battery with the plastic locking latch pointing upward, you will find five primary terminal blade receptors. Pin Position Typical Label Voltage / Signal B+ Main Positive Terminal Nominal 18V / Max 20V DC Middle-Left C1 / ID Balance/Identification Internal Cell-Bank Voltage Telemetry Center TH / T Thermistor Signal Temperature-Dependent Resistance (NTC) Middle-Right C2 / Data Battery Communication Serial Data / Logic Monitoring Far Right B- Main Negative Terminal System Ground (0V Reference) 2. Deep Dive Into Pin Mechanics Power Rails: B+ and B- hart 20v battery pinout diagram better
The far-left terminal (usually marked with a '-' or thick trace). This provides the ground return path.
The Hart 20V battery terminal typically features arranged in a specific pattern. Here is the layout looking at the battery slots (or the ports on the tool): The standard external connector on the battery pack
Some higher-draw tools (like vacuums or impact drivers) use a specialized "fat" positive pin or extra signaling to detect low voltage early and prevent deep discharge. Safety and DIY Considerations
: The TH (Thermistor) pin is a 10kOhm sensor connected to B+. If the battery is too hot or too cold, the charger will refuse to start, and the tool may shut down automatically to protect the hardware. Deep Dive Into Pin Mechanics Power Rails: B+
Beyond the primary five pins, deeper inspection reveals additional contact points (often labeled ) used specifically during the charging process:
Creating custom adapters to power non-HART devices (like RC cars, fans, or lighting) using HART batteries. Repair: Replacing broken battery housings or connectors. 2. HART 20V Battery Pinout Diagram Explained