About this replacement
Sprint Slate 80 / AQT80 — 3.8V Li-Polymer Replacement Battery
This is a 3.8V, 4400mAh (16.72Wh) Li-Polymer cell for the Sprint Slate 80 and AQT80 tablets. It replaces the original battery when the tablet no longer holds charge, shuts down unexpectedly, or fails to power on. Dimensions are 110.00 × 100.06 × 3.20mm — match these before installing.
- Slate 80 and AQT80 compatibility: Both models run the same 3.8V power rail with an identical connector and cell footprint, so a single cell covers both variants without modification.
- Bench tested on actual hardware: We ran full charge and discharge cycles on this cell and monitored the BMS trip points. The protection circuit responded correctly to overcharge, over-discharge, and short-circuit conditions at expected voltage thresholds.
- Fuel gauge reset after installation: After fitting this battery, run one complete discharge to automatic shutoff, then charge uninterrupted to 100% without using the tablet. This lets the fuel gauge IC calibrate against the new cell and corrects the inaccurate percentage readings that commonly appear right after a swap.
Slate 80 shutting down at 15–25% remaining after a battery swap
The Slate 80's fuel gauge IC was calibrated to the old cell's discharge curve. When the new cell hits a voltage cliff — typically around 3.5V under combined display and WiFi load — the tablet interprets this as a critical shutdown threshold even though capacity remains. The fix is one full discharge-to-shutoff cycle followed by an uninterrupted charge to 100%. After that cycle, the IC recalibrates and the reported cutoff aligns with the actual 3.0V cell minimum.
Fast charging not working on the Slate 80 after battery replacement
Fast charge protocols — including USB-PD negotiation — require the charger and device to complete at least one accepted charge handshake with the new cell before the charge IC unlocks higher current. If fast charge does not appear immediately after installation, that is expected behaviour, not a fault. Plug into the original Sprint charger and complete one full charge cycle from under 10% to 100%. After that cycle, fast charge should re-engage on subsequent sessions.