About this replacement
Asus PadFone A80 / Infinity A80 — 3.8V Li-Polymer Replacement Battery (C11-A80)
This is a 3.8V, 2300mAh lithium-polymer cell built to replace the original C11-A80 battery in the Asus PadFone A80 and Infinity A80. It fits the hybrid smartphone body — not the tablet dock. The cell measures 93.61 × 40.76 × 4.14mm and drops into the same cavity as the factory unit.
- PadFone A80 / Infinity A80 / T003 fit: These models share the same chassis dimensions, connector pinout, and BMS handshake protocol — one cell covers all variants listed. The C11-A80 part number is the common OEM reference across the lineup.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the PadFone A80 platform. The BMS accepted the handshake cleanly, charge current ramped as expected, and the protection circuit tripped correctly at low-voltage cutoff.
- Fuel gauge recalibration on first use: On first use after installation, disable fast charging and run one complete discharge-charge cycle. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging pushes current into an uncalibrated counter — skipping this step causes erratic percentage readings in the first few days.
Sudden shutdown at 20–30% on the PadFone A80 after a cell swap
The PadFone A80 pulls hard on the battery when the modem is active and the screen is at full brightness — both loads hit simultaneously during docked tablet use. A new cell with an uncalibrated fuel gauge IC can report 25% remaining while the actual cell voltage has already dropped below the BMS cutoff threshold under load. The phone interprets this as a sudden shutdown rather than a low-battery event. One full discharge-charge cycle with the modem active corrects the coulomb counter and eliminates the false-floor shutdown.
Phone warm near the battery slot during the first few charges after replacement
A new lithium-polymer cell has slightly higher internal impedance than a broken-in cell. During the first two or three charge cycles, the charge IC works against that higher impedance, converting more energy to heat at the cell surface. This is normal and settles as the cell cycles. If the case stays warm past the fourth charge cycle or the phone throttles performance, check that the charge IC has dropped out of fast-charge mode — drop into Settings › Battery and confirm the charge rate has normalised to standard levels.