UMI UMIDIGI Power 3 Replacement Battery 3.85V 5000mAh

UMI UMIDIGI Power 3 — 3.85V Li-Polymer Replacement Battery (1ICP/6/65/87)

This 3.85V, 5000mAh Li-Polymer cell replaces the original battery in the UMIDIGI Power 3 smartphone. It matches the OEM part number 1ICP/6/65/87 and fits the Power 3's physical bay at 86.00 × 64.36 × 5.10mm. Capacity is 19.25Wh — identical to the factory specification.

• UMIDIGI Power 3 fitment: The Power 3 uses a dedicated battery bay with a proprietary connector pinout tied to the fuel gauge IC. This cell matches that connector and communicates correctly with the phone's coulomb counter — no handshake errors reported during testing.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the Power 3 mainboard. The BMS accepted the full 5000mAh charge without tripping an over-voltage cutoff, and the fuel gauge IC tracked state-of-charge accurately after one complete calibration cycle.
• First-cycle fuel gauge reset: After fitting this cell, disable fast charging and run one full discharge down to automatic shutdown, then charge uninterrupted to 100%. This lets the fuel gauge IC map its coulomb-counting baseline against the new cell's discharge curve before fast charge current is applied.

Why the Power 3 reports wrong battery percentage after a cell swap

The UMIDIGI Power 3 uses a fuel gauge IC that stores a learned discharge curve from the original cell. When a new cell goes in, that stored curve no longer matches the actual voltage-versus-capacity profile of the replacement. The IC reads voltage and estimates percentage against the old data, so it can show 40% when the cell is closer to 15%. One full uninterrupted discharge-to-shutdown followed by a complete charge cycle forces the IC to rewrite its reference table. After that cycle, percentage readings stabilise.

Sudden shutdown at 20–30% on the replacement cell

This happens when the cell voltage drops below the phone's minimum load threshold under a high-draw event — typically the LTE modem firing at full power or the screen at peak brightness. A new cell that hasn't been calibrated can sit at a nominal resting voltage that looks like 25% charge, but sags sharply under load, hitting the 3.4V hardware cutoff before the OS has time to trigger a graceful shutdown. Run the first-cycle calibration discharge described above. If shutdowns continue past cycle two, check that the battery connector is fully seated — a partial connection raises contact resistance and worsens voltage sag under load.