Hart 20v Battery: Pinout Diagram

| Terminal Label | Position | Function | |---------------|----------|----------| | | Left (large slot) | Battery Positive (Pack voltage: 18-21V) | | B- | Right (large slot) | Battery Negative / Ground (0V) | | T / TH | Center-left (small slot) | Temperature sense (NTC thermistor to B-) | | ID | Center-right (small slot) | Identification / Communication (One-wire data) |

The battery pack typically consists of 5x 18650 lithium cells in series (5S1P or 5S2P configuration), providing a nominal voltage of 18.5V and a maximum charge voltage of 21V. Hart 20v Battery Pinout Diagram

Top View of Battery (Terminal Side) ┌─────────────────────────────────────────┐ │ ███ │ │ ███ (Mounting rails) │ │ │ │ ┌──────┐ ┌──────┐ ┌──────┐ │ │ │ B+ │ │ T │ │ ID │ │ │ │ (C) │ │ (TH) │ │ (S) │ │ │ └──────┘ └──────┘ └──────┘ │ │ │ │ ┌──────────┐ │ │ │ B- │ │ │ │ (GND) │ │ │ └──────────┘ │ │ │ └─────────────────────────────────────────┘ (Large slot) = B+, B- (Small slots) = T, ID | Terminal Label | Position | Function |

(Orientation: Battery upside down, terminals facing you) B- (Small slots) = T

Knowing the pinout unlocks several useful projects.