About this replacement
UMI UMIDIGI A7 Pro — 3.85V Li-Polymer Replacement Battery (1ICP/5/65/87)
This is a 3.85V, 4000mAh Li-Polymer battery for the UMIDIGI A7 Pro smartphone. It replaces the original cell when the phone holds a short charge, shuts down unexpectedly, or will no longer power on. Capacity is 4000mAh (15.4Wh), matching the OEM specification under part number 1ICP/5/65/87.
- UMIDIGI A7 Pro fitment: The A7 Pro uses a 76.30 x 64.40 x 4.40mm Li-Polymer cell on a 3.85V rail. This battery matches that physical footprint and voltage. The BMS connector and charge IC handshake are confirmed against the A7 Pro's power management circuit.
- Bench tested on actual hardware: We ran the cell through full charge and discharge cycles on the A7 Pro. The BMS accepted the charge protocol correctly, and the fuel gauge IC tracked state-of-charge without erratic jumps after the first complete cycle.
- First-cycle calibration tip: On first use after installation, disable fast charging for one complete discharge-charge cycle. This lets the fuel gauge IC recalibrate its coulomb counter against the new cell's discharge curve before high-current charging begins on an uncalibrated cell.
Why the UMIDIGI A7 Pro reports wrong battery percentage after a cell swap
The A7 Pro uses a fuel gauge IC that builds its state-of-charge model against the old cell's discharge curve. When a new cell goes in, that learned curve no longer matches reality. The IC may show 40% charge while the actual cell voltage is already at 3.6V or lower. One full discharge down to automatic shutdown, followed by an uninterrupted charge to 100%, resets the coulomb counter and brings the percentage readings back in line with actual cell voltage.
Sudden shutdown at 20–30% on the replacement cell
This happens when the fuel gauge IC still holds the old cell's low-voltage threshold model. The replacement cell hits a voltage cliff — it cannot sustain the rail under modem or display load — before the IC registers a low-battery warning. The phone cuts out because the actual cell voltage drops below 3.4V while the gauge still reads 25%. Run one full unconstrained discharge cycle to automatic shutdown, then charge uninterrupted to 100%, and the IC will recalibrate its cutoff threshold to the new cell.