GIONEE A1 Lite BL-N4000Y Replacement Battery 3.85V 4000mAh

GIONEE A1 Lite Series — 3.85V Li-Polymer Replacement Battery (BL-N4000Y)

This is a 3.85V, 4000mAh (15.4Wh) Li-Polymer replacement cell for the GIONEE A1 Lite, A1 Lite Dual SIM, and A1 Lite Dual SIM TD-LTE. It replaces OEM part BL-N4000Y using the same physical footprint — 86.12 x 62.48 x 4.15mm — and the same connector pinout. Fit this when the original cell no longer holds charge through a standard day of calls, messaging, and screen-on use.

• A1 Lite variant coverage: All three listed variants — standard, Dual SIM, and Dual SIM TD-LTE — share the same battery bay dimensions, flex connector, and BMS communication protocol. One cell fits all three without modification.
• Bench tested on actual hardware: We ran charge and discharge cycles through the A1 Lite's charge IC and confirmed the BMS handshake completes without fault codes. Charge acceptance held steady across both standard and fast-charge current profiles.
• Fuel gauge recalibration on first cycle: After fitting this cell, disable fast charging and run one full discharge-to-charge cycle at standard rate. The A1 Lite's fuel gauge IC is calibrated to the old cell's discharge curve — a slow first cycle lets it re-map against the new cell before high-current charging begins.

Sudden shutdown at 20–30% on the replacement cell

New Li-Polymer cells have a steeper voltage cliff than worn cells at low state of charge. The A1 Lite's modem and display together pull enough current to collapse cell voltage below the BMS cutoff threshold — even when the fuel gauge still shows charge remaining. This is not a defective cell. The fuel gauge IC is reading an old coulomb-count model that does not match the new cell's actual discharge curve. Run two complete discharge-charge cycles at standard rate and the shutdowns will stop as the IC recalibrates.

Phone warm near the battery compartment on first charge

A new high-impedance cell generates more heat during initial charge cycles than a worn, low-impedance cell does. The A1 Lite's charge IC delivers the same current regardless, so a higher internal resistance means more heat dissipated inside the cell during the first two or three charges. This is normal and settles as impedance drops with cycling. If the device stays warm beyond the third full charge cycle, check that the battery flex connector is fully seated — a partial connection forces the charge IC into an error-recovery loop that sustains elevated current.