Aiptek MPVR Replacement Battery ZPT-NKA 3.7V 1000mAh

Aiptek MPVR Digital Media — 3.7V Li-ion Replacement Battery (ZPT-NKA)

This is a 3.7V, 1000mAh Li-ion cell for the Aiptek MPVR Digital Media portable video recorder and media player. It replaces OEM part ZPT-NKA. Fit the battery when the original no longer holds a charge or the device fails to power on.

• MPVR platform fit: The MPVR uses a single Li-ion cell running a 3.7V rail to power both the recording controller and playback decoder. This replacement cell matches that voltage rail and uses the same physical footprint — 52.95 × 33.07 × 8.01mm — so the connector seats correctly against the BMS contact board.
• Bench tested on actual hardware: We cycled this cell through full charge and discharge on a Li-ion test rig. The BMS tripped at the correct cutoff voltage on discharge and accepted charge current without thermal excursion. Capacity read within tolerance of 1000mAh at standard 0.2C draw.
• Fuel gauge recalibration on first cycle: After fitting this cell, run one complete discharge down to automatic shutoff, then charge fully without interruption. The MPVR's fuel gauge IC calibrates its internal coulomb counter against that first full cycle — skipping it causes the percentage display to drift from the first day of use.

Why the MPVR reports a wrong battery percentage after a cell replacement

The MPVR stores a discharge curve in its fuel gauge IC that was mapped to the original factory cell. When a new cell goes in, that stored curve no longer matches the new cell's actual voltage-to-capacity relationship. The gauge reads voltage and translates it to a percentage using the old map, so it can be off by 15–20% in either direction. One full discharge-to-shutoff followed by an uninterrupted full charge resets the coulomb counter and remaps the curve to the new cell.

MPVR shuts down suddenly while the percentage still shows 20–30%

This is a voltage cliff failure. Under the combined load of the recording encoder and LCD backlight, the cell's terminal voltage drops faster than the fuel gauge tracks. When voltage falls below the BMS cutoff threshold — typically 3.0V under load — the device shuts off even though the gauge still shows charge remaining. A degraded or deeply discharged cell reaches that cliff much earlier in its discharge curve. If the replacement cell shows this symptom, leave it on charge for a full uninterrupted cycle and confirm charge voltage reaches 4.2V before removing from the charger.