ZTE A699 Replacement Battery 3.7V 1300mAh Li-ion

VIBO ZTE A699 — 3.7V Li-ion Replacement Battery

This is a 3.7V, 1300mAh Li-ion cell for the ZTE A699 smartphone. It replaces the original battery when the phone no longer holds charge or fails to power on. Capacity matches the factory specification at 4.81Wh.

• ZTE A699 fit: The A699 uses a compact removable cell — 43.50 x 47.00 x 6.10mm — with a direct connector to the device's charge IC. This cell matches those physical dimensions and the voltage rail the A699's BMS expects to handshake with on insertion.
• Bench tested on actual hardware: We cycled this cell through full discharge and charge sequences, confirming the BMS engages correctly, charge IC accepts current input, and the cell holds voltage across the discharge curve without premature cutoff.
• Fuel gauge recalibration on first use: After fitting this cell, disable fast charging and run one complete discharge-to-charge cycle at standard rate. This lets the A699's fuel gauge IC map its coulomb counter to the new cell's actual discharge curve before high-current charging is applied to an uncalibrated cell.

Sudden shutdown at 20–30% on the ZTE A699 after a cell swap

This happens because the fuel gauge IC is still referencing the discharge curve of the old, degraded cell. The new cell has a steeper voltage drop near the bottom of its range, and the modem or screen load pulls the cell below the BMS cutoff threshold before the reported percentage reaches zero. The phone reads 25% but the actual cell voltage has already dipped under 3.2V under load. One full uninterrupted discharge cycle — letting the phone run down to auto-shutdown, then charging to 100% without interruption — recalibrates the coulomb counter to the new cell.

Phone feels warm near the battery during the first few charges

A fresh Li-ion cell has slightly higher internal impedance than a broken-in cell. During the first charge cycles, the charge IC pushes current into higher resistance, which produces more heat than normal. This is temporary — impedance drops after three to five charge cycles as the cell's electrolyte settles. If warmth continues beyond five full cycles or the phone becomes hot to the touch, check that the battery connector is fully seated, as a loose pin increases contact resistance and worsens heating.