NEC N910 Replacement Battery 3.7V 750mAh Li-ion 6320000510

NEC N910 / GV880 / CLN910 — 3.7V Li-ion Replacement Battery (6320000510)

This is a 3.7V, 750mAh Li-ion cell built to replace part number 6320000510 in the NEC N910, GV880, and CLN910 handsets. These compact early-2000s devices use a fixed internal cell that degrades after repeated charge cycles. When the original cell can no longer hold voltage under load, this replacement restores full function.

• N910, GV880, and CLN910 compatibility: All three models share the same 3.7V cell format, connector pinout, and BMS handshake protocol — that's why a single part number covers all three. Swapping in this cell requires no modification to the charge circuit or contacts.
• Bench tested on actual hardware: We cycled this cell through full discharge and charge sequences on the N910 platform. The BMS accepted charge without fault flags, and the charge IC held the correct 4.2V termination voltage throughout.
• Fuel gauge recalibration after install: On first use, disable fast charging if available and run one complete discharge-charge cycle before normal use. This lets the fuel gauge IC map its coulomb counter against the new cell's actual discharge curve — without it, percentage readings will drift during the first few days.

Sudden shutdown at 20–30% on the NEC N910 after a cell swap

This is a voltage cliff problem, not a capacity problem. The N910's display and modem draw peak current simultaneously during active calls or screen-on events. If the fuel gauge IC is still calibrated to the old, degraded cell curve, it can report 25% remaining while the actual cell voltage has already dropped to the 3.4–3.5V cutoff threshold. The phone's protection circuit shuts down to prevent going below 3.0V per cell. One full uninterrupted discharge-charge cycle resets the coulomb counter and aligns the percentage display with the real discharge curve.

Device not powering on after the replacement cell sat in storage

Li-ion cells self-discharge in storage, and if this battery sat below 2.5V before installation, the BMS will have entered lockout mode to prevent cell damage. The N910 will show nothing — no boot screen, no charging indicator — when connected to power in this state. Connect the phone to a wall charger and leave it untouched for 20–30 minutes. Most BMS controllers on this cell format will begin a trickle pre-charge cycle that brings the cell back above the 2.9V recovery threshold before allowing normal charging to resume.