GIONEE BL-N4000 GN5001 Replacement Battery 3.8V 4000mAh

GIONEE GN5001 / V187 Series — 3.8V Li-Polymer Replacement Battery (BL-N4000)

This is a 3.8V, 4000mAh Li-Polymer replacement battery for the GIONEE GN5001, GN5001S, GN5001L, and V187 smartphones. OEM part number BL-N4000. It fits when the original cell has degraded, lost hold-time, or will no longer accept a charge.

• GN5001 / GN5001S / GN5001L / V187 fit group: These four models share the same battery bay dimensions, connector pinout, and charge management IC handshake. One cell covers all four — no adapter or modification needed.
• Bench tested on actual hardware: We cycled this cell through a full charge and load discharge on the GN5001 platform. The BMS accepted the charge curve without fault flags, and the protection circuit tripped correctly at the low-voltage cutoff threshold.
• Fuel gauge recalibration on first install: On first use after fitting this cell, disable fast charging and run one complete discharge-charge cycle at standard rate. The fuel gauge IC is still calibrated to the old cell's discharge curve. One slow cycle lets it re-map against the new cell before high-current charging begins.

Why the GN5001 reports wrong battery percentage after a cell swap

The GN5001 uses a coulomb-counter-based fuel gauge IC that builds its capacity model over charge cycles on the original cell. When you fit a new cell, the IC still references the old discharge curve. This causes the percentage readout to jump, stall, or show full charge at voltages that do not match real cell state. One full discharge to automatic shutdown — then a complete charge to 100% at standard rate — forces the IC to reset its reference points against the new cell. After that single cycle, percentage tracking stabilises.

Sudden shutdown at 20–30% on the replacement cell

This happens when the cell voltage drops below what the modem or display backlight needs under peak load, even though the fuel gauge still shows charge remaining. A fresh Li-Polymer cell has slightly higher internal impedance before it beds in, which amplifies the voltage sag during high-draw moments. The phone's under-voltage protection cuts power before the OS can log a proper shutdown. Two to three full charge-discharge cycles reduce cell impedance and close the gap — if shutdowns persist past the third cycle, measure resting cell voltage after a full charge; it should read at or above 4.18V.