Asus ZenFone 3 Zoom C11P1612 Replacement Battery 3.85V 5000mAh

Asus ZenFone 3 Zoom — 3.85V Li-Polymer Replacement Battery (C11P1612)

This 3.85V, 5000mAh Li-Polymer battery replaces the C11P1612 cell inside the Asus ZenFone 3 Zoom, ZenFone 3 Zoom Dual SIM LTE, ZE553KL, and ZenFone 3 Zoom S. It physically matches OEM dimensions at 87.64 × 64.54 × 4.80mm, so the ribbon connector and frame tabs seat correctly. Capacity is rated at 19.25Wh — identical to the original cell specification.

• ZE553KL and Dual SIM LTE compatibility: Both variants use the same 3.85V power rail, identical flex connector pinout, and the same BMS handshake protocol — so one cell covers the full ZenFone 3 Zoom lineup without modification.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on a ZE553KL unit. The BMS accepted the charge IC handshake cleanly, balance protection triggered correctly at full capacity, and over-discharge cutoff held at the expected floor voltage.
• Fuel gauge recalibration on first use: After installation, disable fast charging and run one complete discharge-to-charge cycle at standard rate. The fuel gauge IC on this phone calibrates its coulomb counter against the cell's discharge curve — skipping this step leaves the IC mapping a 5000mAh curve against the old cell's degraded profile.

Why the ZenFone 3 Zoom shuts down suddenly at 20–30% after a cell swap

The ZE553KL's fuel gauge IC holds a learned discharge curve from the original cell. When a new cell with a different internal impedance profile goes in, the IC's voltage-to-percentage mapping is wrong. Under high-draw moments — modem handoff, screen at full brightness, GPS active — the new cell's actual voltage drops below what the IC predicts, triggering an emergency shutdown before the displayed percentage reaches zero. One full calibration cycle forces the coulomb counter to relearn the cell floor, typically resolving cutoffs that happen above 15%.

USB fast charge not activating on the first cycle after replacement

The ZenFone 3 Zoom's charge IC negotiates fast charge entry after reading the BMS state on the new cell. On a fresh cell with no cycle history, the BMS may respond outside the expected handshake window, causing the charge IC to fall back to standard 5V input. This is not a fault — it clears after the first complete charge cycle once the BMS has a state-of-charge baseline recorded. If fast charge still does not activate after two full cycles, verify the cable supports the required current and try a different USB port rated at 2A or above.