GIONEE GN800 Replacement Battery BL-G021A 3.7V 2300mAh

GIONEE GN800 / GN708 / GN878 Series — 3.7V Li-Polymer Replacement Battery (BL-G021A)

This is a 3.7V, 2300mAh (8.51Wh) lithium-polymer cell built to the BL-G021A spec. It fits the Gionee GN800, GN708T, GN708W, and GN878 smartphones. Dimensions are 71.50 × 58.53 × 4.60 mm — measure your original before ordering if you're unsure which variant you have.

• GN800 / GN708 / GN878 platform fit: These models share the same battery bay geometry, connector pinout, and BMS handshake protocol, which is why a single cell covers the range. The BL-G021A part number confirms OEM-matched cell chemistry and protection circuit layout.
• Bench tested on actual hardware: We cycled the cell on a GN800 unit and monitored BMS behaviour through charge and discharge. The protection circuit held cutoff cleanly at the low-voltage threshold with no spurious trips under display and modem load.
• Fuel gauge recalibration on first use: On first use after installation, disable fast charging and run one full discharge-to-charge cycle. This allows the fuel gauge IC to recalibrate its coulomb counter against the new cell's discharge curve before high-current charging pushes current into an uncalibrated state.

Sudden shutdown at 20–30% on the GN800 after a cell swap

The GN800's fuel gauge IC stores a discharge curve map calibrated to the original cell. When you swap in a new cell, the IC still uses the old map. At around 20–30% reported charge, the new cell's actual voltage drops below what the modem and display demand under load — the BMS cuts power to protect the cell even though the OS shows charge remaining. This is a voltage cliff, not a fault with the replacement cell. Run two full discharge-charge cycles without fast charging and the fuel gauge IC will remap to the new cell's actual voltage curve.

Phone warm near the battery during the first few charges after replacement

A new lithium-polymer cell has higher internal impedance than a broken-in cell. During the first charge cycles, the charge IC pushes current into that higher resistance, and some of that energy converts to heat. This is normal and typically settles after three to five cycles as the cell's internal impedance drops. If the phone stays warm beyond five cycles, check that the charge current isn't being forced into fast-charge mode — hold the phone on a standard 5V/1A charger for the first few cycles to keep heat generation low.