About this replacement
Lenovo TAB E7 (TB-7104F) — 3.85V Li-Polymer Replacement Battery (L18D1P31)
This is a 3.85V, 2650mAh Li-Polymer battery for the Lenovo TAB E7 tablet (TB-7104F). It replaces OEM part L18D1P31 — the original power cell in this 7-inch Android tablet. It matches the original cell's voltage, physical footprint (71.00 × 59.50 × 3.70mm), and connector pinout.
- TB-7104F fitment: The TAB E7 ships as a single hardware revision under the TB-7104F model code. The battery connects via a shared flex connector and BMS pinout — there are no sub-variants requiring a different cell.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on a TB-7104F unit. The BMS accepted the new cell without triggering a fault state, and the charge IC ramped to full without thermal cutoff.
- 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 against the new cell's actual capacity curve and corrects the inaccurate percentage readings that commonly appear after a battery swap.
TAB E7 shutting down at 15–25% remaining
This happens when the fuel gauge IC is still calibrated to the degraded old cell. The voltage floor it expects no longer matches the new cell's discharge curve. Under combined display and WiFi load, the tablet sees a voltage drop it interprets as empty — and cuts off. Run one full discharge to automatic shutoff followed by an uninterrupted charge to 100%. After that single cycle, the gauge re-anchors to the new cell and the early shutoff stops.
Fast charging not available after battery replacement on the TAB E7
The TAB E7's charge IC uses a negotiation handshake on the first accepted charge cycle to confirm cell parameters before enabling higher charge rates. A brand-new cell that has not completed one full charge is treated conservatively — the IC defaults to standard 5V charging until it has a baseline. Plug into the original Lenovo charger and let the first charge run uninterrupted to 100% without removing the cable. Fast charge availability is typically restored from the second cycle onward.