Google Pixel 2 G8 Replacement Battery 3.7V 2200mAh

Google Pixel 2 G8 — 3.7V Li-ion 2200mAh Replacement Battery (35H00123-22M)

This is a 3.7V, 2200mAh Li-ion replacement battery for the Google Pixel 2 (G8). It fits the original battery slot and restores power capacity lost to cell degradation. OEM part numbers covered include 35H00123-00M, 35H00123-02M, 35H00123-03M, 35H00123-22M, RHOD160, BA S390, and BA S420.

• Pixel 2 G8 compatibility: All listed OEM part numbers share the same 3.7V rail, physical footprint (65.00 × 43.28mm), and connector pinout. The BMS handshake protocol is consistent across the G8 revision range, so the fuel gauge IC on the Pixel 2 mainboard communicates with this cell without modification.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on a Pixel 2 unit. The BMS held charge cutoff at 4.2V and triggered low-voltage protection cleanly below 3.0V with no false-trip events under screen and modem load.
• Fuel gauge recalibration on first cycle: On first use after installation, disable fast charging and run one full discharge-charge cycle at standard rate. This lets the Pixel 2 fuel gauge IC map the new cell's discharge curve before the coulomb counter begins tracking state-of-charge accurately.

Why the Pixel 2 reports wrong battery percentage after a cell swap

The Pixel 2 uses a fuel gauge IC that learns cell behaviour over many charge cycles. When you install a new cell, the IC still holds calibration data from the old, degraded cell. That mismatch causes the reported percentage to drift — often reading 40% when the cell is near empty. One full slow-charge cycle from 0% to 100% resets the learned curve and brings the displayed percentage back into alignment with actual cell voltage.

Sudden shutdown at 20–30% on the replacement cell

This happens when the cell voltage drops below the modem or display load threshold before the fuel gauge registers critical. A fresh cell with an uncalibrated coulomb counter cannot accurately predict the voltage cliff under high-current draw. The Pixel 2's power IC cuts the system before Android can log a low-battery warning. Run one full discharge cycle without fast charging — once the fuel gauge has a real baseline, shutdowns at 20–30% stop.