About this replacement
DeWalt 2802K / 2812K Series — 12V Ni-MH Replacement Battery (DC9071 / DE9071)
This is a 12V 1500mAh Ni-MH replacement battery for the DeWalt 2802K compact cordless drill/driver and related 12V platform tools. It replaces OEM part numbers including DC9071, DE9071, DE9075, DW9072, and DE9501, among others. Voltage matches the original 12V rail; capacity is 1500mAh (18Wh) as specified.
- 12V DeWalt platform fit: The 2802K, 2812B, 2812K, and 2832K share the same 12V Ni-MH pack format — identical connector pin-out, cell count, and BMS handshake voltage. One pack covers the full series without modification.
- Bench tested on actual hardware: We ran this pack through charge and load cycles on a 12V DeWalt drill platform. The BMS held cutoff thresholds consistent with the OEM spec, and cell balance stayed within acceptable delta-V across discharge.
- Motor inrush break-in on first use: Run the drill at half load for two cycles before applying maximum torque. This lets the BMS log the motor inrush current draw and calibrate its overcurrent protection threshold before you hit full-load fastening.
BMS overcurrent trip on trigger-pull inrush in the 2802K
The 2802K motor pulls a sharp current spike in the first milliseconds of each trigger pull. A new or cold Ni-MH pack has slightly elevated internal resistance, which can push the instantaneous voltage drop past the BMS overcurrent threshold before the motor reaches running speed. This trips the pack off before the drill does any work. Running two half-load break-in cycles reduces internal resistance enough to keep inrush within the BMS window.
Charger won't recognise the pack after it's been sitting unused
Ni-MH cells self-discharge during storage — if the pack voltage drops below roughly 10V total (around 0.83V per cell in a 12-cell pack), some DeWalt 12V chargers will refuse to start a charge cycle and signal a fault. The fix is a brief trickle charge at low current to bring cell voltage back above the charger's acceptance threshold. If your charger has a conditioning or recovery mode, use it now. Otherwise, a compatible Ni-MH charger set to 100–200mA will recover the pack in a slow charge cycle before normal charging resumes.