When using a Hart battery for DIY projects (like powering a custom LED light or a small robot), you only need the pins for power. However, it is vital to add your own Low Voltage Protection (LVP) circuit, as Hart batteries typically do not have a built-in cutoff to prevent over-discharging; that protection is usually built into the tool itself. Voltage Readings to Expect Fully Charged: ~20V to 21V (unloaded). Nominal Voltage: 18V.
If your HART battery won't charge or run a tool: hart 20v battery pinout diagram better
For diagnostic or DIY purposes, the following approximate voltages can be expected on a charged battery: Positive to Negative Positive to TH Negative to C Negative to TH Negative to ID Key Features of HART 20V Batteries On-Board Fuel Gauge When using a Hart battery for DIY projects
| Negative to ... | Voltage Reading | | :--- | :--- | | Negative | 0V | | TH | 0V | | ID | 0V | | Control (C) | 20V | | C1 | 4V | | C2 | 8V | | C3 | 12V | | C4 | 16V | Nominal Voltage: 18V