Asus ZenFone 4 Selfie Lite C11P1613 Replacement Battery 3.85V 4000mAh

Asus ZenFone 4 Selfie Lite (ZB520KL) — 3.85V Li-Polymer Replacement Battery (C11P1613)

This 3.85V, 4000mAh (15.4Wh) Li-Polymer battery replaces the original C11P1613 cell in the Asus ZenFone 4 Selfie Lite, 4 Selfie Lite Dual SIM LTE, and ZB520KL variants. It slots into the same physical space and connects to the same flex cable as the factory unit. Dimensions are 80.28 x 64.52 x 4.32mm — confirm these against your existing cell before ordering.

• ZB520KL variant coverage: The ZenFone 4 Selfie Lite shipped in single-SIM and Dual SIM LTE configurations — both use the same C11P1613 cell, same voltage rail, same connector, and same BMS handshake. One replacement cell covers all variants in this line.
• Bench tested on actual hardware: We cycled this cell through full charge and discharge on the ZB520KL platform. The BMS accepted the charge controller handshake without fault flags, and voltage held stable under combined screen and modem load throughout the test.
• Fuel gauge recalibration on first cycle: On first use after installation, disable fast charging and run one complete discharge-charge cycle at standard current. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging is introduced — skipping this step is the leading cause of erratic percentage readings after a swap.

Why the ZB520KL reports wrong battery percentage after a cell swap

The ZenFone 4 Selfie Lite uses a coulomb counter and fuel gauge IC that builds its state-of-charge model against the original cell's discharge curve. When you install a new cell, the IC still references that old calibration. The mismatch produces percentage readouts that jump or plateau — the phone may show 40% while the cell is closer to 15%. One full discharge to auto-shutdown followed by a full charge at standard current resets the IC's reference points. After that cycle, percentage reporting tracks accurately.

Sudden shutdown at 20–30% on the replacement cell

This is a voltage cliff issue, not a capacity fault. When the modem fires a data burst or the screen brightness spikes, current draw pulls the cell voltage below the BMS cutoff threshold — even though the fuel gauge still shows charge remaining. On a degraded original cell this happens because internal resistance has climbed; on a new cell it happens when the fuel gauge IC hasn't yet calibrated to the new discharge curve. Run the recalibration cycle described above. If shutdowns persist past two full cycles, check that the battery flex connector is fully seated — a partial connection raises effective internal resistance and triggers the same early cutoff. Target open-circuit voltage after a full charge should read 4.35V at the connector.