Microsoft Surface Pro X 1876 Keyboard Compatible Battery 7.58V

Microsoft Surface Pro X 1876 Keyboard — 7.58V Li-Polymer Replacement Battery (G3HTA060H)

This is a 7.58V, 5000mAh Li-Polymer cell that replaces the original battery in the Microsoft Surface Pro X 1876 detachable keyboard. It fits the keyboard accessory—not the Surface Pro X tablet itself. The keyboard uses this cell to power its wireless connectivity, backlighting, and input functions.

• Surface Pro X 1876 Keyboard fit: The 1876 keyboard uses a slim Li-Polymer pack measuring 231.10 x 107.60 x 3.10mm to fit within the keyboard's ultra-thin housing. The G3HTA060H connector and BMS handshake are specific to this accessory—no other Surface keyboard generation uses the same configuration.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the 1876 keyboard hardware. The BMS accepted the charge cycle without fault flags, and the keyboard's pairing and input functions remained stable throughout testing.
• Fuel gauge recalibration after install: After fitting this battery, run one full discharge to automatic shutoff, then charge uninterrupted to 100%. The fuel gauge IC on the 1876 keyboard calibrates against the new cell during that first full cycle, correcting any inaccurate percentage readout that appears immediately after the swap.

Why the Surface Pro X Keyboard shows 0% or a frozen percentage after a battery swap

The 1876 keyboard's fuel gauge IC stores calibration data tied to the original cell's charge curve. When a new cell goes in, the IC has no reference point for the new chemistry profile, so it reports stale or nonsensical values. This is not a fault with the replacement cell. One complete discharge-to-shutoff followed by an uninterrupted charge to 100% writes fresh calibration data to the IC and restores accurate reporting.

Surface Pro X Keyboard dropping from 30% to dead with no warning

This happens when the fuel gauge IC loses track of the actual voltage floor of the new cell. The keyboard's firmware triggers a hard shutoff at a voltage threshold the old calibration set—not where the new cell actually runs out. The cell still has charge, but the system cuts power before reaching it. Run the recalibration cycle described above; after one full discharge and recharge, the cutoff threshold resets to the correct voltage floor for this cell.