About this replacement
Makita 1050D Series — 12V Ni-MH Replacement Battery (1220 / 1222 / 192598-2)
This is a 12V 1500mAh Ni-MH replacement battery for the Makita 1050D cordless drill and its variants. It fits the 1050DA, 1050DRA, 1050DWA, and over 147 additional Makita 12V models that share the same battery platform. OEM part numbers covered include 1220, 1222, 192598-2, 192681-5, 193981-6, and several others in that family.
- 1050D platform compatibility: Every model in this series runs the same 12V rail with the same slide-in connector and matching cell count. The BMS negotiation and charge termination behaviour are identical across variants, so one cell pack covers the full range without modification.
- Bench tested on actual hardware: We ran this pack on a 1050D under repeated trigger pulls and sustained fastening loads. The BMS held steady through motor-start inrush spikes and terminated charge cleanly at full capacity without false cutoffs.
- Break-in on the 1050D drill: On first use, run the drill at half load — light fastening, not heavy drilling — for two cycles before any maximum-torque application. This lets the BMS log the motor's inrush current signature before it sets its overcurrent protection thresholds.
BMS overcurrent trip on motor-start inrush in the 1050D
When you pull the trigger on the 1050D, the motor draws a short, sharp current spike before it reaches running speed. On a new pack, the BMS has no stored profile for that inrush level and may trip at a lower threshold than the actual motor demands. This shows up as the drill cutting out immediately on trigger pull, even with a fully charged battery. Running two light-load break-in cycles gives the BMS enough data to raise its overcurrent threshold to match the 1050D motor's real start-up draw.
Charger won't recognise the new pack after extended storage
Ni-MH cells that have sat in storage can drop below the voltage floor the charger uses to detect a valid pack — typically under 10V on a 12V Ni-MH. The charger sees a reading outside its acceptance window and refuses to start a charge cycle, often showing a blinking or error indicator. To recover, place the pack in the charger and check the terminal voltage with a multimeter. If cells are above 9V but the charger still won't engage, try a different Makita 12V charger — some older units have a narrower acceptance window than newer DC1414 series chargers.