Google Pixel 2B Replacement Battery BG2W 3.85V 2700mAh

Google Pixel 2 — 3.85V Li-Polymer Replacement Battery (BG2W)

This is a 3.85V, 2700mAh Li-Polymer cell replacing the BG2W battery in the Google Pixel 2 (Pixel 2B / Pixel 2 Muski). It fits the original battery bay without modification. Swap it when your Pixel 2 shuts down early, charges slowly, or no longer holds a full day of charge.

• Pixel 2 (Muski / 2B) fit: Both Pixel 2 variants use the same BG2W cell with identical voltage rails, connector pinout, and BMS handshake. One SKU covers both board revisions — no adapter or harness swap needed.
• Bench tested on actual hardware: We cycled this cell on a Pixel 2 mainboard and confirmed the BMS handshake completed, charge IC accepted the cell on first connect, and voltage held stable under full modem and display load.
• Fuel gauge recalibration on first use: After installation, disable fast charging and run one full discharge-to-charge cycle before enabling Adaptive Charging. This lets the fuel gauge IC map the new cell's discharge curve before high-current pulses are applied to an uncalibrated cell.

Sudden shutdown at 20–30% on the Pixel 2 after a battery swap

The Pixel 2 fuel gauge IC stores a learned discharge curve from the old cell. When a new cell goes in, that curve no longer matches actual cell voltage under load. The modem and display draw a combined surge the old curve doesn't account for, so the IC reads a false low-voltage condition and triggers an emergency shutdown — even though the cell still has charge. One full discharge cycle below 5% and a complete charge to 100% forces the coulomb counter to rebuild its reference table against the new cell.

USB-PD fast charge not accepted on the first cycle after replacement

After a cell swap, the Pixel 2 charge IC defaults to trickle charge on the first connect while it checks cell impedance. If the phone doesn't recognise a fast charge handshake in this window, it stays in standard charge mode for the entire first cycle. This is normal BMS behaviour — not a fault with the cable or charger. Fully discharge and recharge once, and fast charge will re-engage on the second cycle when cell impedance registers within the expected range.