AA3S1P1000 Compatible Battery 3.6V 1000mAh Ni-MH Pack

Custom Battery Packs AA3S1P1000 — 3.6V Ni-MH Replacement Battery Pack

This is a 3.6V, 1000mAh Ni-MH replacement battery pack for OEM part number AA3S1P1000. Three cells wired in series deliver a stable 3.6V rail at 3.6Wh usable energy. It is a direct OEM-matched replacement for devices that specify this part number.

• Three-cell series configuration: Three Ni-MH cells wired in series share the same voltage rail and connector pinout as the original pack. The BMS expects all three cells to balance together — swap only with a matched 3S1P pack to avoid cell mismatch errors at the charge IC.
• Bench tested on actual hardware: We cycled this pack through charge and discharge on the bench. The BMS engaged correctly at both ends of the voltage window, and no premature cutoff was triggered during the conditioning run.
• First-cycle calibration: Run one full charge-to-discharge cycle immediately after installation. Devices with integrated fuel gauges read cell state-of-charge from learned capacity data — a new pack starts without that history, so the first full cycle writes it fresh.

Pack running at lower voltage than rated on first install

Ni-MH packs ship at storage voltage, typically 3.2–3.4V across three cells rather than the rated 3.6V. The device may flag low battery or behave erratically before the pack has ever been charged. This is normal — charge the pack fully before first use. After a full charge cycle, resting voltage should read 3.6V or above across the pack terminals.

Pack not reaching full charge on the first cycle

Some charge ICs apply a reduced current limit when they detect a new or deeply discharged Ni-MH pack — this is a deliberate protection behaviour, not a fault. The first charge may terminate early or report less than full capacity. Run a full discharge down to the BMS cutoff, then charge again. Capacity typically normalises within two to three cycles as the charge IC learns the pack's internal resistance profile.