About this replacement
Asus ZenFone 4.5 A450CG — 3.7V Li-Polymer Replacement Battery (C11P1403)
This is a 3.7V, 1700mAh Li-Polymer cell for the Asus ZenFone 4.5 (A450CG). It replaces OEM part numbers C11P1403 and 0B200-01070000. Swap this in when the original cell no longer holds a useful charge or has swollen past safe use.
- ZenFone 4.5 / A450CG fit: Both model designations share the same PCB layout, connector pinout, and BMS handshake protocol — one cell covers both. The 59.90 × 56.10 × 4.30 mm footprint matches the OEM battery bay with no case modification needed.
- Bench tested on actual hardware: We ran this cell through charge acceptance, BMS cutoff, and over-discharge recovery on the A450CG. The BMS triggered protection at the correct low-voltage threshold and accepted a full charge cycle without thermal events.
- Fuel gauge recalibration on first use: After installation, disable fast charging and run one complete discharge-to-charge cycle before normal use. This lets the ZenFone's fuel gauge IC map its coulomb counter against the new cell's discharge curve — skipping this step causes early percentage jumps.
Sudden shutdown at 20–30% on the A450CG after a cell swap
A new Li-Polymer cell has a slightly different voltage-versus-capacity curve than the worn cell it replaces. The ZenFone's fuel gauge IC still references the old curve, so it misjudges remaining capacity. Under modem or display load, the cell voltage drops below the BMS cutoff threshold before the OS sees 0% — and the phone shuts off. One full discharge cycle from 100% down to auto-shutoff, then a full charge, forces the coulomb counter to resync. After that cycle, the reported percentage should track the actual cell state within a few percent.
Phone warm near the battery during the first few charge cycles
A fresh Li-Polymer cell has higher internal impedance than a cell that has been through several cycles. The A450CG's charge IC pushes the same current profile it used on the broken-in original, and the higher resistance in the new cell converts more of that energy to heat during the first two or three charges. This is expected and tapers off as the cell's impedance drops with use. If the phone stays warm past the fifth full charge cycle, check that the back cover is fully seated — poor thermal contact with the chassis can trap heat near the cell.