Google Pixel Fold GT6SS Replacement Battery 3.87V 3250mAh

Google Pixel Fold — 3.87V Li-Polymer Replacement Battery (GT6SS)

This is a 3250mAh Li-Polymer replacement battery for the Google Pixel Fold foldable smartphone. It runs at 3.87V and replaces OEM part number GT6SS. Fit the Pixel Fold when the original cell has degraded and no longer holds a useful charge.

• Pixel Fold compatibility: The Pixel Fold uses a single main battery cell behind the primary display hinge assembly. The GT6SS part number ties directly to that cell's connector pinout and BMS handshake — other Pixel cells share the brand but differ in voltage rail and connector, so they are not interchangeable here.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the Pixel Fold mainboard. The BMS accepted the cell, reported state-of-charge correctly after one full cycle, and charge current stepped down as expected during the CV phase.
• Fuel gauge recalibration on first use: On first use after installation, disable fast charging and run one complete discharge-to-charge cycle at standard rate. This lets the fuel gauge IC map its coulomb counter against the new cell's discharge curve before high-current charging pushes significant current into an uncalibrated cell.

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

The Pixel Fold's fuel gauge IC stores a learned discharge curve from the original cell. When a new cell goes in, that stored curve no longer matches the actual cell chemistry. The gauge reads voltage and maps it to a percentage using old reference data, so the number on screen drifts from reality. One full discharge and full charge cycle at standard rate overwrites the reference and re-anchors the percentage reading to the new cell.

Sudden shutdown at 20–30% on the replacement cell

This happens when the modem, the outer display, and the inner display all draw current at the same time and the cell voltage sags below the BMS cutoff threshold — even though the reported percentage still looks healthy. A freshly installed cell with an uncalibrated fuel gauge is most vulnerable on the first few cycles because the gauge doesn't yet know where the real voltage cliff sits. Run the phone through two full discharge-charge cycles at standard charge rate. After calibration, the gauge will begin reporting shutdown closer to 5–10% where the actual voltage floor lies, typically around 3.4–3.5V under load.