Asus ZenFone Zoom C11P1507 Replacement Battery 3.85V 2900mAh

Asus ZenFone Zoom ZX550 — 3.85V Li-Polymer Replacement Battery (C11P1507)

This 3.85V, 2900mAh Li-Polymer battery replaces the OEM cell in the Asus ZenFone Zoom and ZenFone Zoom Dual SIM (ZX550 / X550). It carries part numbers C11P1507, 0B200-01670100, and C11PjC1 — all the same physical cell across ZenFone Zoom variants. If your original battery no longer holds charge or the phone shuts down unexpectedly, this is the direct swap.

• ZenFone Zoom ZX550 and X550 fitment: Both the standard and Dual SIM variants use the same battery bay dimensions (68 × 57 × 4.50mm), the same connector, and the same BMS communication protocol — so one cell covers the full ZenFone Zoom lineup.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the ZX550 platform. The BMS accepted the cell without fault flags, charge current ramped normally, and the protection circuit tripped correctly at the low-voltage cutoff threshold.
• Fuel gauge recalibration on first use: After installation, disable fast charging and complete one full discharge-to-charge cycle before using the phone normally. This lets the fuel gauge IC map the new cell's discharge curve — skipping this step causes the OS to report inaccurate percentages for the first several cycles.

Sudden shutdown at 20–30% on the ZenFone Zoom after a cell swap

The ZenFone Zoom's Snapdragon 550 platform draws a sharp current spike when the modem switches bands or the rear camera module fires up. A new cell with an uncalibrated fuel gauge IC will report 25% remaining while the actual open-circuit voltage is closer to 3.5V — right at the edge of the BMS low-voltage cutoff. Under that load spike, cell voltage sags below the cutoff threshold and the BMS kills power instantly. One full discharge-charge cycle with fast charging off recalibrates the coulomb counter and eliminates most of these phantom shutdowns.

USB fast charging not activating after replacement

On the first charge cycle after a cell swap, the ZenFone Zoom's charge IC may default to standard 5V / 1A input instead of triggering Asus's fast charge handshake. This happens because the charge controller sees a new cell with no prior state data and applies a conservative pre-charge current until it confirms cell health. Plug in, let the phone charge fully at standard rate, then unplug and reconnect — the fast charge protocol typically activates from the second cycle onward. If it still does not activate, check that the cable supports the required current — a charging-only cable will block the data-line handshake entirely.