Microsoft Surface Book 3 13.5 Keyboard Compatible Battery 11.36V 4800mAh

Microsoft Surface Book 3 13.5 Keyboard — 11.36V Li-Polymer Replacement Battery (G3HTA065H)

This 11.36V, 4800mAh (54.53Wh) Li-Polymer battery replaces the OEM G3HTA065H cell inside the detachable keyboard base of the Surface Book 3 13.5-inch. The keyboard base houses its own independent battery pack, separate from the display unit. Replacing this cell restores full keyboard, trackpad, and base-mode functionality.

• Surface Book 3 13.5 keyboard base fit: The 13.5-inch keyboard base uses a dedicated battery rail and BMS that communicates charge state to Windows independently from the display battery. Voltage and connector specs must match exactly — this cell meets both requirements for that unit.
• Bench tested on actual hardware: We cycled this cell through the Surface Book 3 keyboard base BMS and confirmed charge acceptance, proper state-of-charge reporting, and stable voltage across the full discharge curve without BMS trip events.
• Fuel gauge recalibration after install: After fitting this battery, run the keyboard base down to automatic shutoff, then charge it uninterrupted to 100% before detaching the display. This one full cycle resets the fuel gauge IC against the new cell and clears the inaccurate percentage readings that typically appear after a swap.

Why the Surface Book 3 keyboard base shows a different charge percentage than the display

The Surface Book 3 runs two separate battery systems — one in the display, one in the keyboard base — and Windows reports them independently in the taskbar flyout. After a keyboard battery replacement, the base BMS has no calibration data for the new cell, so the reported percentage drifts from actual capacity. This is a firmware-level fuel gauge issue, not a hardware fault. One full discharge-to-shutoff followed by an uninterrupted charge to 100% gives the BMS the data it needs to report accurately.

Surface Book 3 keyboard battery stuck at 0% and not charging after replacement

If the keyboard base reports 0% and won't accept a charge after install, the BMS may have entered a protection state during shipping or handling at low voltage. Connect the Surface Book 3 to the Surface Connect charger with the keyboard attached and leave it for at least 20 minutes without waking the device. The charge IC needs a trickle phase to bring the cell above the BMS re-enable threshold — typically around 3.0V per cell — before normal charging resumes. If the percentage remains at 0% after 30 minutes on charge, detach and reattach the keyboard base to trigger a fresh BMS handshake with Windows.