About this replacement
Asus ZenFone 6 A600CG / T00G — 3.8V Li-Polymer Replacement Battery (C11P1325)
This is a 3300mAh Li-Polymer cell at 3.8V nominal, built to the C11P1325 specification. It fits the Asus ZenFone 6 line — including the A600, A600CG, and T00G variants. At 12.54Wh, it matches the original cell's energy envelope exactly.
- ZenFone 6 A600 / A600CG / T00G fit: All three variants share the same chassis dimensions, battery connector pinout, and charge IC handshake. The C11P1325 cell slides into each without a wiring adapter — the BMS communicates over the same two-wire SMBus line across the whole family.
- Bench tested on actual hardware: We ran this cell through full charge-discharge cycles on a ZenFone 6 T00G. The BMS accepted the cell on first insertion, charge IC stepped through trickle, CC, and CV phases cleanly, and the coulomb counter tracked capacity from 0% to 100% without dropout.
- First-cycle fast charge protocol: On first use after installation, disable fast charging for one complete discharge-charge cycle. This lets the fuel gauge IC recalibrate its discharge curve against the new cell before high-current charging pushes current into an uncalibrated cell — preventing early percentage drift.
Sudden shutdown at 20–30% on the ZenFone 6 after a cell swap
The ZenFone 6 fuel gauge IC stores a discharge curve calibrated to the old, degraded cell. A new cell has a steeper voltage cliff at the low end — the phone sees 3.6V and maps it to 20%, but the new cell actually drops faster under modem or display load than the old curve predicted. The phone cuts out because the voltage rail drops below the processor's minimum before the OS sees 0%. One full discharge-to-shutdown followed by a full charge resets the coulomb counter against the new cell's actual curve.
Phone not powering on after the replacement cell sat in storage
Li-Polymer cells self-discharge in storage. If this cell shipped or sat unused long enough to drop below 2.5V, the BMS enters lockout mode and blocks charge current to prevent copper dendrite formation. Plugging into a standard charger does nothing — the phone stays dark. Connect to a USB charger and leave it untouched for 20–30 minutes; the charge IC delivers a trickle current below the BMS lockout threshold to nudge the cell back above 2.7V, after which the BMS re-initialises and normal charging resumes.