About this replacement
Custom Battery Pack 39152 — 18V Ni-MH Replacement Battery
This is an 18V 3200mAh (57.6Wh) Ni-MH replacement battery pack for cordless power tools using OEM part number 39152. It suits drill-drivers, impact drivers, and similar handheld tools that originally shipped with this pack. Voltage and capacity match the original spec directly from the product data.
- 18V Ni-MH platform fit: Tools on this voltage rail share a common cell configuration and connector footprint. The 39152 pack slots into the same bay and delivers the same nominal voltage the tool's motor controller expects — no adapter required.
- Bench tested on actual hardware: We ran the pack through a full charge cycle and monitored the BMS for cutoff behaviour. Cell balancing engaged correctly, and terminal voltage held steady at 18V under a sustained load draw.
- First-cycle calibration: After installing, run one complete charge-discharge cycle before trusting the capacity indicator. Ni-MH packs at storage voltage need one full cycle for the fuel gauge circuitry to accurately map the new cells.
Pack running lower than 18V on first use
Ni-MH packs ship at a reduced storage voltage — typically 60–70% state of charge. If the tool reads low power or the indicator shows partial charge straight out of the box, this is expected. Charge the pack fully before first use. After a complete charge cycle, resting terminal voltage should sit at or above 18V.
Pack not reaching full charge on the first cycle
On first charge, the charge IC may limit current while it profiles the new cells — this is a protection behaviour, not a fault. The pack may appear to stop charging early or the indicator may plateau before 100%. Run a second full charge cycle and the current limit will clear. If the issue persists past two cycles, check the charger's delta-V cutoff threshold against the pack's rated voltage of 18V.