About this replacement
Makita BFH120F Series — 12V Ni-MH Replacement Battery (193346-2)
This is a 12V, 1500mAh Ni-MH replacement battery for the Makita BFH120F cordless hammer drill/driver and a wide range of compatible 12V Makita tools including the BFL081F, BFL121F, and BFL200F. It replaces OEM part numbers 193346-2, 193349-6, BH1220, BH1233, and variants. Drop voltage and chemistry match the original pack exactly.
- 12V Ni-MH platform compatibility: The BFH120F, BFL121F, and related models share the same 12V Ni-MH battery platform — same connector housing, same cell voltage stack, same BMS handshake protocol. One pack services all of them without modification.
- Bench tested on actual hardware: We ran this pack through charge and discharge cycles on the BFH120F. The BMS held protection thresholds correctly under repeated trigger-pull inrush loads, and the charger recognised the pack on first insertion without fault codes.
- Ni-MH break-in on the BFH120F: Run two full cycles at half load — light drilling and driving only — before pushing the drill into hardwood or using hammer mode. Ni-MH cells reach rated capacity after initial conditioning; skipping this step can cause the BMS to set conservative overcurrent thresholds that limit torque output.
BMS overcurrent trip on trigger-pull inrush with the BFH120F
When you pull the trigger on a cordless drill, the motor draws a brief but sharp inrush current — often three to five times the steady running current. On a new or freshly stored Ni-MH pack, the BMS may not yet have profiled that spike and can trip overcurrent protection instantly. This cuts the tool dead on trigger pull even though the battery appears fully charged. Running two break-in cycles at reduced load lets the BMS log the actual inrush signature and widen the protection window accordingly.
Charger not recognising this pack after storage
Ni-MH cells self-discharge during storage, and if a pack sits long enough, cell voltage can drop below the charger's acceptance threshold — typically around 1.0V per cell. The Makita charger reads this as a fault and refuses to begin a charge cycle. To recover the pack, briefly apply a trickle charge using a compatible Ni-MH charger set to a low rate, or hold the charger's reset function if your model supports it, until cell voltage climbs above 1.0V per cell. Once the pack clears that floor, the charger will accept it and complete a normal charge cycle.