Makita 1210 12V Ni-MH Replacement Battery 2100mAh

Makita 5092D / 6011D Series — 12V Ni-MH Replacement Battery (1210 / 632277-5)

This is a 12V, 2100mAh Ni-MH replacement battery for the Makita 5092D, 5092DW, 6011D, and 6011DW cordless drills. It replaces OEM part numbers 1210 and 632277-5. Use it when your original pack no longer holds a charge or delivers consistent torque under load.

• 5092D, 5092DW, 6011D, 6011DW compatibility: These four models share the same 12V battery platform, slide-in connector geometry, and BMS handshake protocol — one pack services all four without any modification.
• Bench tested on actual hardware: We ran this pack on a 5092DW under repeated trigger pulls and sustained fastening cycles. The BMS tracked inrush current correctly on each motor start and held the voltage rail stable through the test sequence without tripping overcurrent protection.
• First-use load conditioning for Ni-MH: On first use, run the drill at half load — light drilling, not max-torque fastening — for two full discharge-charge cycles. This allows the cell chemistry to reach full electrolyte saturation before you push the pack through high-inrush motor starts at full trigger.

BMS overcurrent trip on trigger-pull inrush in the 5092D

When you pull the trigger on a cordless drill, the motor draws a spike of current several times higher than its running load — this is inrush. On a degraded or unconditioned Ni-MH pack, internal resistance spikes at the same moment, pushing the BMS past its overcurrent threshold before the bit even starts turning. The result is an immediate cutout that looks like a dead battery but clears the moment you release the trigger. Running two break-in cycles at reduced load trains the BMS to profile that inrush spike correctly, keeping the pack online through normal trigger pulls.

Charger not recognising the pack after extended storage

Ni-MH packs that have been sitting unused can self-discharge below the voltage floor the charger uses to confirm a healthy cell — typically around 1.0V per cell, or roughly 10V at the pack level on a 10-cell 12V unit. When the charger sees a pack below that threshold, it refuses to enter charge mode and may flash an error or simply stay dark. The fix is a recovery charge: some Makita chargers have a conditioning mode; if yours does not, use a compatible charger that supports a trickle pre-charge to bring the pack above 10.5V, at which point the standard charge cycle will engage normally.