About this replacement
Lenovo XiaoXin Pad Pro 2024 — 3.91V Li-Polymer Replacement Battery (L24D2P31)
This is a 3.91V, 8400mAh (32.84Wh) lithium-polymer cell for the Lenovo XiaoXin Pad Pro 2024 tablet. It matches OEM part numbers L24D2P31 and SB18E12521. The cell powers the display, processor, and all internal components through normal tablet use.
- XiaoXin Pad Pro 2024 fit: The L24D2P31 cell uses a connector pinout and BMS handshake that match the XiaoXin Pad Pro 2024 charge controller. The fuel gauge IC communicates with the tablet's system board over the same voltage reference lines as the original cell — no adapter or firmware workaround needed.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on the XiaoXin Pad Pro 2024 board. The BMS accepted charge negotiation on the first cycle, and the charge controller reported correct cell state without tripping any protection flags.
- Fuel gauge recalibration after swap: After installation, run one full discharge to automatic shutoff, then charge uninterrupted to 100%. This resets the fuel gauge IC calibration against the new cell. Skipping this step causes the tablet to report inaccurate percentages in the first few days of use.
Tablet shutting down at 15–25% remaining after battery replacement
The XiaoXin Pad Pro 2024 shuts down early when the fuel gauge IC is still calibrated to the old cell's voltage curve. Under combined display and WiFi load, voltage sags faster than the uncalibrated gauge predicts. The system reads that sag as a critically low state and triggers a forced shutdown before the actual charge is depleted. One full discharge-to-shutoff followed by an uninterrupted charge to 100% realigns the gauge and stops early cutoffs.
Fast charging not available after fitting the L24D2P31 cell
USB-PD negotiation between the charger and the tablet's charge IC resets after a battery swap. On the first charge, the system may fall back to standard 5V input while it re-establishes the power contract. This is normal behaviour — it is not a fault with the cell. Disconnect the charger fully, wait 10 seconds, reconnect, and the USB-PD handshake completes at the correct voltage. If fast charging still does not appear after the second connection, confirm the charger output is at least 18W at 9V.