About this replacement
Lenovo PB1-770N / PB1-770N Dual SIM TD-LTE — 3.8V Li-Polymer Replacement Battery (L14D1P31)
This is a 3.8V, 3400mAh Li-Polymer replacement battery for the Lenovo Yoga Tablet 7 (PB1-770N), including the Dual SIM TD-LTE variant. Part number L14D1P31 matches the OEM cell format and connector. Dimensions are 96.60 × 83.13 × 2.80 mm — measure your existing cell before installing.
- PB1-770N and Dual SIM TD-LTE coverage: Both variants share the same motherboard power rail, L14D1P31 connector pinout, and BMS handshake protocol. One cell covers both SKUs without modification.
- Bench tested on actual hardware: We cycled this cell through full charge and discharge on a PB1-770N unit. The BMS negotiated charge termination correctly at 4.35V and held the cutoff floor at 3.0V under load without triggering premature shutdown.
- First-cycle fuel gauge reset on the PB1-770N: After installation, disable fast charging and run one full discharge-to-charge cycle. The tablet's fuel gauge IC calibrates its coulomb counter against the new cell's discharge curve on that first pass — skipping this step causes percentage jumps and false low-battery shutdowns.
Sudden shutdown at 20–30% on the PB1-770N after a cell swap
The PB1-770N's SoC draws a short, high-current spike when the screen brightness peaks or Wi-Fi reassociates. A new cell with an uncalibrated fuel gauge IC can show 25% remaining while the actual cell voltage has already sagged below 3.2V under that load spike. The BMS interprets the voltage drop as a hard undervolt and cuts power instantly. Running one full discharge cycle forces the coulomb counter to map the real capacity curve of the new cell, eliminating the mismatch between displayed percentage and actual voltage state.
Battery percentage jumping erratically on the Yoga Tablet 7 after replacement
The fuel gauge IC on the PB1-770N was calibrated to the impedance profile of the original cell. A new cell has a different internal resistance, so the IC's voltage-to-percentage lookup table produces erratic jumps — often skipping 10–15% in seconds. This is not a faulty cell. Discharge the tablet fully until it shuts down, then charge uninterrupted to 100% without removing the charger. After that single cycle the fuel gauge IC anchors its endpoints and the percentage display stabilises.