About this replacement
Lenovo IdeaPad S2110A / IdeaTab S2110 Series — 3.7V Li-Polymer Replacement Battery (L12D2P31)
This 3.7V, 6300mAh Li-Polymer battery replaces the original L12D2P31, L11C2P31, and L11M2P31 cells used in the Lenovo IdeaPad S2110A, IdeaTab S2110, and IdeaTab S2110AF tablets. All three OEM part numbers share the same physical format, connector pinout, and BMS handshake — one replacement covers the full range. Capacity is 6300mAh (23.31Wh), matching the original specification.
- S2110 series compatibility: The IdeaPad S2110A and both IdeaTab S2110 variants run the same 3.7V power rail with an identical dock-style connector and three-pin BMS interface. The fuel gauge IC communicates over that same bus, so the replacement cell negotiates charge termination and state-of-charge reporting without hardware modification.
- Bench tested on actual hardware: We cycled this cell on an S2110A mainboard and confirmed the BMS accepted charge without fault flags, voltage held steady through display-plus-WiFi combined load, and the protection circuit triggered correctly at the low-voltage cutoff threshold.
- Fuel gauge recalibration after swap: After fitting the new cell, run the tablet down to automatic shutoff — do not force-close it — then charge uninterrupted to 100% without unplugging early. This single cycle lets the fuel gauge IC map its discharge curve against the new cell and corrects the inaccurate percentage readings that appear immediately after installation.
Why the IdeaTab S2110 shuts down at 15–25% remaining
The S2110 drives a 10-inch IPS panel and a WiFi radio simultaneously from a single 3.7V cell. When both loads spike together — backlight at full brightness plus active data transfer — instantaneous current draw pulls the cell voltage below the BMS cutoff threshold faster than the fuel gauge can update its displayed percentage. The tablet interprets that voltage dip as a dead cell and shuts down, even though the reported percentage still reads 15–25%. After fitting a new cell, run one full discharge-to-shutoff cycle then charge to 100% without interruption. That recalibration pass aligns the fuel gauge curve to the new cell's actual capacity floor and eliminates the premature shutdown.
Fast charging unavailable after battery replacement on the S2110A
The S2110A's charge IC uses a negotiation handshake on the first accepted charge cycle to set the input current limit against the fitted cell. If the tablet is unplugged before that first cycle completes, the handshake resets and the device defaults to standard 500mA USB input on subsequent sessions. To restore the higher charge rate, plug into the original Lenovo wall adapter — not a generic USB port — and leave the tablet charging uninterrupted until the status indicator confirms 100%. One complete cycle is all the charge IC needs to lock in the correct input profile.