The HART charger communicates via SMBus (System Management Bus). If you try to use a generic Li-Ion charger (like an iMax B6) directly on B+ and B-, the battery will reject the charge. Connect your charger leads to B+ and B-, but also connect a 10k NTC thermistor between T and B- to simulate room temperature. Without this, the BMS assumes the battery is on fire (infinite resistance) and cuts the circuit.
The control pin is the gatekeeper. It is used by the charger to manage the charging process and by the battery’s internal BMS (Battery Management System) to enable or disable the pack if a fault is detected, such as a short circuit or over‑current condition.
Second, a better pinout diagram enables . Hart tools are popular for their value proposition, but like all power tools, they eventually fail. Often, the failure is not in the motor but in the battery’s BMS, which can “brick” itself if the voltage drops too low. A superior diagram includes voltage test points and common logic levels (e.g., “Data line runs at 3.3V logic”). For the repair technician, this information is gold. It allows them to use a benchtop power supply to “jump-start” a sleeping BMS via the C and D pins or to verify that the thermistor is providing a correct resistance curve. Without this detailed pinout, the $100 battery pack becomes unrecyclable e-waste. With it, it can be resurrected.
: The main positive power supply blade.
If you want to use a HART 20V battery to power an LED strip, a portable soldering iron, or a 3D-printed power station, you mainly need the and (-) terminals. However, be warned: most HART tools have the Low Voltage Cutoff (LVC) built into the tool , not the battery. If you run a device directly off the pins without a protection circuit, you risk draining the battery below 15V, which can permanently "brick" the cells. 2. Troubleshooting "Dead" Batteries
Whether you are troubleshooting a battery that won’t charge, designing a custom adapter, or simply curious about what makes your cordless tools tick, a better grasp of the pinout diagram empowers you to work smarter and safer. Always remember to respect the power of lithium‑ion technology and follow all manufacturer safety guidelines.
With a clear pinout, you can build adapters to power custom projects. For instance, the connects to a Hart 20V battery and provides accessible positive and negative terminals for DIY electronics, RC vehicles, or lighting setups. hart 20v battery pinout diagram better
If your charger is flashing a red "defective" light, you can use a multimeter to check the voltage between the and (-) pins. Healthy: 16V to 20V.
Another small, central pin. The ID pin helps the smart charger identify the battery type and capacity to regulate charging current and prevent charging issues.
Another communication line for "smart" features, ensuring the battery and tool/charger are compatible. The HART charger communicates via SMBus (System Management
A pinout is a diagram showing the function of each electrical contact (pin) on a device's connector. The Hart 20V battery uses a 5-pin interface that, like most modern smart batteries, does much more than just supply positive and negative power.
Immediately transfer the revived battery to an official Hart Tools Charger to complete a proper balance-charging cycle. Safety Protocols and Maintenance