Bella 1590 Replacement Battery 1.2V 2500mAh Ni-MH

Bella 1590 / 1591 Series — 1.2V Ni-MH Replacement Battery

This is a 1.2V, 2500mAh Ni-MH cell built as a direct replacement for the internal battery in Bella model 1590, 1590B, 1590C, and 1591 electric toothbrushes, plus seven additional compatible models. When the original cell can no longer hold a useful charge, this swap restores full motor function without replacing the entire handle. Voltage and capacity match the OEM specification exactly.

• 1590 series handle compatibility: The 1590, 1590B, 1590C, and 1591 handles all run the same 1.2V Ni-MH cell at the same physical dimensions — 48.70 × 16.82 × 16.82mm. Same voltage rail, same connector tab layout, same BMS threshold. One cell fits across the range.
• Bench tested on actual hardware: We cycled this cell through the inductive charging base and monitored BMS behaviour across the first three charge cycles. Charge acceptance was consistent by cycle two, and motor draw stabilised at the correct current for full brushing speed.
• Dock charging discipline for Ni-MH cells: Remove the toothbrush from the charging base once the indicator shows full. Ni-MH chemistry is more sensitive to continuous trickle charge from inductive bases than Li-ion — leaving it docked 24/7 accelerates capacity fade noticeably faster than removing it and returning it below 30%.

Toothbrush losing brushing power before the battery indicator shows low

Ni-MH cells in toothbrush handles experience voltage sag under the brief high-current pulse the brush motor pulls at startup. A degraded cell may show adequate resting voltage — enough to keep the indicator lit — but sag below the motor's operating threshold the moment the motor engages. The result is a handle that appears charged but runs weak or stutters during brushing. The cell is the cause, not the motor.

New battery installed but the handle won't charge on the base

The 1590 series uses inductive charging, which requires the handle to sit precisely centred on the base post for the coil pair to couple correctly. If the brush head isn't fully seated — or the handle is slightly canted — charge transfer drops to near zero. After installing a new cell, set the handle squarely on the base and confirm the indicator light activates within 30 seconds. If it doesn't, recheck seating and verify the base has power before assuming the cell is faulty.