About this replacement
Google Pixel 3A XL — 3.85V Li-Polymer Replacement Battery (G020A-B)
This 3600mAh Li-Polymer cell replaces the original G020A-B battery in the Google Pixel 3A XL (G020C). It runs at 3.85V nominal and stores 13.86Wh. Fit this cell when your original battery no longer holds charge, causes unexpected shutdowns, or has visibly swollen.
- Pixel 3A XL / G020C compatibility: Both device variants use the same connector pinout, flex cable routing, and BMS handshake protocol — one cell covers both. Voltage and cell dimensions match the original bay: 75.25 × 63.58 × 4.50mm.
- Bench tested on actual hardware: We cycled this cell in a Pixel 3A XL under mixed screen-on and modem loads. The BMS accepted charge from the Pixel's charge IC without fault codes, and the fuel gauge IC registered cell capacity within two full cycles.
- First-cycle fast-charge protocol: On first use after installation, turn off Adaptive Charging for one full discharge-to-charge cycle. This gives the fuel gauge IC time to map the new cell's discharge curve before the charge IC pushes fast-charge current into an uncalibrated cell.
Sudden shutdown at 20–30% on the replacement cell
This is a voltage-cliff failure, not a capacity problem. Under sustained modem or display load, the new cell's voltage drops faster than the fuel gauge IC expects based on its stored discharge curve from the old cell. The phone interprets the voltage drop as a critical low-battery event and shuts down — even though the coulomb counter still shows charge remaining. Run one complete discharge from 100% to auto-off, then charge to 100% without interruption. After that cycle, the fuel gauge IC recalibrates its curve to the new cell and the false cutoff stops.
Phone won't power on after sitting in storage with a flat battery
If the cell dropped below roughly 2.5V per cell during storage, the BMS enters a protection lockout and blocks normal charge current. The phone shows nothing on screen when plugged in. Connect the device to a charger and leave it for 15–20 minutes without pressing any button — the charge IC trickle-charges the cell at low current until voltage clears the BMS lockout threshold. Once the cell climbs back above 3.0V, the BMS releases and normal charging resumes.