About this replacement
Lenovo Yoga Tablet 2-851F / 830F Series — 3.75V Li-ion Replacement Battery (L14C2K31)
This is a 3.75V, 6400mAh (24Wh) Li-ion battery for the Lenovo Yoga Tablet 2-851F, Yoga Tablet 2-830F, Yoga Tablet 2 L851F, and Yoga Tablet 2 830LC. It replaces OEM part numbers L14C2K31 and L14D2K31. Fit is confirmed across the 8-inch Android tablet range that shares this cell format and connector pinout.
- Yoga Tablet 2 family compatibility: The 851F, 830F, L851F, and 830LC variants share the same 3.75V single-cell architecture, connector pitch, and BMS handshake protocol — which is why one cell covers all four. The PCB protection circuit is identical across the run.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on the Yoga Tablet 2 platform. The BMS accepted the cell without error flags, the fuel gauge IC initialised correctly, and charge current tapered normally at the top-of-charge threshold.
- Post-install calibration for the Yoga Tablet 2: After fitting this cell, run one full discharge until the tablet auto-shuts off, then charge uninterrupted to 100%. The fuel gauge IC on this tablet needs at least one full cycle against the new cell to reset its learned capacity model — skipping this leaves the percentage readout unreliable for the first week of use.
Why the Yoga Tablet 2 reports poor battery health immediately after a cell swap
The Yoga Tablet 2 stores charge history and health data in EEPROM on the battery's protection circuit board. When you fit a new cell, that EEPROM is blank or carries factory default values the OS reads as degraded. Android's battery health indicator pulls from this stored data, not from a live measurement. Running one full discharge-to-shutoff followed by a full uninterrupted charge writes fresh cycle data to the fuel gauge IC and clears the erroneous health warning.
Tablet shuts down at 15–25% charge shown on screen
This happens when the fuel gauge IC's state-of-charge map no longer matches the actual cell's voltage curve — common after a cell swap. The tablet hits the hardware low-voltage cutoff (around 3.0V under load) while the gauge still shows charge remaining. The fix is a calibration cycle: drain fully to auto-shutdown, leave for two minutes, then charge straight to 100% without interruption. After two to three of these cycles the percentage readout and the actual cutoff voltage align.