BLP707 Oppo F11 Replacement Battery 3.85V 3900mAh

Oppo F11 / CPH1911 — 3.85V Li-Polymer Replacement Battery (BLP707)

The BLP707 is a 3.85V, 3900mAh Li-Polymer cell that fits the Oppo F11, F11 Premium Edition, F11 Premium Edition Dual, and CPH1911. It replaces the original battery when capacity has dropped from normal charge cycles. Install it to restore the phone to its original power delivery specs.

• F11 series compatibility: The F11, F11 Premium Edition, and CPH1911 all share the same battery bay dimensions and connector pinout. The BLP707 cell matches the 89.00 × 64.50 × 3.90mm form factor and voltage rail these variants require.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the F11 platform. The BMS accepted the cell without triggering thermal cutoff, and the charge IC stepped through trickle, CC, and CV phases as expected on a fresh cell.
• Fuel gauge recalibration on first use: On first use after installation, disable VOOC fast charging for one complete discharge-charge cycle. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging pushes into an uncalibrated coulomb counter.

Sudden shutdown at 20–30% on the Oppo F11 after a cell swap

A new Li-Polymer cell has a slightly different voltage-versus-capacity curve compared to the aged cell the fuel gauge IC was trained on. When the phone hits a load spike — 5G handoff, screen at full brightness, or camera — the cell voltage dips below the shutdown threshold even though the reported percentage says 25%. The IC reads a safe state of charge but the actual terminal voltage collapses under current draw. One full discharge-charge cycle resets the coulomb counter and aligns the IC to the new cell curve, stopping the spurious shutdowns.

VOOC fast charge not activating on the first cycle after replacement

Oppo's VOOC protocol requires a handshake between the charger, the phone's charge IC, and the battery BMS. On a freshly installed cell with no charge history, the BMS may respond outside the expected voltage window, causing the charge IC to fall back to standard 5V charging instead of negotiating VOOC. This is normal on cycle one. Complete one full standard charge first, then reconnect the VOOC adapter — the BMS will have initialised correctly and the handshake succeeds at the correct voltage band.