BlackView E7 Replacement Battery 3.8V 2750mAh Li-Polymer

BlackView E7 — 3.8V Li-Polymer Replacement Battery (E7)

This 3.8V, 2750mAh (10.45Wh) lithium-polymer cell replaces the internal battery in the BlackView E7 smartphone. It fits the E7 directly, restoring power to devices where the original cell has degraded or failed. Dimensions are 89.30 × 63.00 × 4.00mm — confirm clearance before installation.

• E7 platform fit: The BlackView E7 uses a fixed internal cell with a specific connector pinout and BMS handshake tied to the device's charge IC. This replacement matches that pinout and voltage rail so the charge IC recognises the cell without triggering a fault state.
• Bench tested on actual hardware: We cycled this cell through full charge and discharge on the bench and monitored BMS cutoff thresholds. The protection circuit held cutoff at the expected low-voltage floor and the charge IC accepted a full CC-CV charge profile without error flags.
• Fuel gauge recalibration on first use: On first use after installation, disable fast charging and complete one full discharge-charge cycle at standard rate. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging pushes energy into an uncalibrated coulomb counter.

Sudden shutdown at 20–30% on the replacement cell

After a cell swap, the fuel gauge IC still holds the old cell's discharge curve in memory. The new cell's voltage drops faster under modem and screen load than the old degraded cell did — so the IC hits its low-voltage cutoff well before the percentage reads zero. The phone interprets that hard voltage drop as an emergency shutdown, not a normal power-off. Run one full discharge to cutoff, then charge uninterrupted to 100% to push the coulomb counter through a complete reference cycle.

USB charging not accepted on the first cycle after fitting

Some charge ICs on the E7 perform a handshake with the battery BMS before allowing charge current above trickle level. On a fresh cell that has never been cycled in this specific device, that handshake can time out, leaving the phone showing a charging icon but drawing minimal current. Connect to a 5V standard charger — not a fast charger — and leave it for 20 minutes before checking again. Once the BMS completes its first recognition cycle, normal charge current resumes and fast charge protocols re-enable on subsequent cycles.