About this replacement
DOOV A8 — 3.8V Li-Polymer Replacement Battery (PL-C30)
This is a 3.8V, 3000mAh (11.4Wh) Li-Polymer cell built to replace the original PL-C30 battery in the DOOV A8 smartphone. It fits directly into the A8 battery bay and connects to the same flex cable and charge IC. Use this when the original cell no longer holds a usable charge or fails to power the phone through a normal day.
- DOOV A8 fit: The A8 uses a fixed connector pinout and a specific physical envelope — 85.20 × 66.90 × 3.20 mm. This cell matches both. The BMS handshake between the charge IC and this cell passes without error flags on the A8 board.
- Bench tested on actual hardware: We cycled this cell through full charge and discharge runs on the A8 platform. The charge IC accepted the cell without thermal cutoff, and BMS protection thresholds engaged correctly at both high and low voltage limits.
- First-cycle fast charge disable: After installation, run one complete discharge-charge cycle with fast charging turned off. This gives the fuel gauge IC time to map the new cell's discharge curve before high-current charging begins — skipping this step causes the percentage readout to drift for days.
Why the DOOV A8 reports wrong battery percentage after a cell swap
The A8's fuel gauge IC builds its capacity model from coulomb counting against the previous cell's discharge curve. When you install a fresh cell, that stored model no longer matches the actual chemistry. The IC keeps applying the old curve, so the percentage it displays can read high or low by 10–20%. One full discharge to shutdown followed by a full charge to 100% forces the IC to recalibrate against the new cell. After that single cycle, the readings stabilise.
Sudden shutdown at 20–30% on the replacement cell
This happens when the fuel gauge IC hasn't yet learned the new cell's voltage-cliff profile. Under modem or screen load, cell voltage can drop sharply below the protection threshold before the displayed percentage reaches zero — the phone cuts out because actual cell voltage hits the BMS floor, not because the percentage says so. Run a full discharge cycle without interruption and let the phone shut down naturally. After one complete recalibration cycle, the gauge catches the voltage drop earlier and the premature shutdown stops. If it persists after two full cycles, check that cell voltage at rest reads above 3.7V with a meter at the flex connector.