About this replacement
Lenovo ThinkPad 10 Tablet — 3.75V Li-Polymer Replacement Battery (45N1726)
This 3.75V, 8700mAh lithium-polymer battery replaces the internal cell in the Lenovo ThinkPad 10 tablet and Z3795. It matches the original form factor at 179.70 x 129.10 x 3.80 mm and covers OEM part numbers 45N1726 through 45N1733. Voltage and capacity match the original charge IC expectations exactly.
- ThinkPad 10 and Z3795 compatibility: Both devices share the same battery bay dimensions, connector pinout, and BMS handshake protocol — the same cell covers both without modification.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on a ThinkPad 10 unit. The BMS accepted the cell without fault codes, and charge IC communication completed normally on first contact.
- Fuel gauge recalibration after swap: After installing this battery, run the tablet down to automatic shutoff, then charge uninterrupted to 100% without using the device. This forces the fuel gauge IC to map its thresholds against the new cell and clears the inaccurate percentage readings that commonly appear after a battery swap.
Why the ThinkPad 10 shuts down at 15–25% remaining
The ThinkPad 10 runs a 10-inch IPS display and a WiFi radio simultaneously under normal use — both draw current at the same time. When battery voltage drops into the lower charge band, this combined load pulls the cell voltage below the BMS cutoff threshold faster than the percentage indicator predicts. The fuel gauge IC was calibrated to the old cell's discharge curve, not the new one. One full discharge-to-shutoff cycle followed by an uninterrupted full charge resets the calibration and stops premature shutdowns.
Fast charging not available after battery replacement
The ThinkPad 10 uses a USB-based charging protocol that requires the charge controller to complete one accepted charge cycle before unlocking higher current delivery. If fast charging appears unavailable immediately after a swap, this is expected behaviour — the charge IC has not yet confirmed cell health. Charge the tablet fully using the original Lenovo charger without interruption. After one complete cycle, the charge controller renegotiates current delivery and fast charge resumes at the normal rate.