Hisense T80 Replacement Battery 3.7V 1280mAh Li-ion

Hisense T80 — 3.7V Li-ion Replacement Battery (T80)

This is a 3.7V, 1280mAh Li-ion replacement battery for the Hisense T80 smartphone. It fits directly into the T80 handset and restores charging from a degraded or failed original cell. Capacity is 4.74Wh at the nominal voltage.

• Hisense T80 fitment: The T80 battery bay uses a specific connector pinout and cell footprint — 64.40 × 43.40 × 4.60mm. This cell matches those physical dimensions and the connector orientation so the charge IC sees a valid battery signal on first boot.
• Bench tested on actual hardware: We cycled this cell through full charge and discharge on the T80 platform. The BMS accepted the cell without fault flags, and the charge IC reached cutoff voltage cleanly without thermal events.
• Fuel gauge recalibration after install: On first use after fitting this cell, disable fast charging and run one complete discharge-charge cycle at standard rate. This lets the fuel gauge IC map the new cell's discharge curve before fast charge pushes high current into an uncalibrated state — which causes percentage jumps and early shutdowns.

Why the T80 reports wrong battery percentage after a cell swap

The T80's fuel gauge IC stores a learned discharge curve from the original cell. When you fit a new cell, that stored curve no longer matches actual cell behaviour. The gauge reads voltage and cross-references the old curve, so the percentage shown on screen drifts from reality. One full slow-rate discharge-charge cycle lets the coulomb counter reset and relearn against the new cell's actual voltage-capacity relationship.

Sudden shutdown at 20–30% on the replacement cell

This happens because the cell voltage drops sharply under modem or display load — a voltage cliff the fuel gauge did not predict. The T80's protection circuit triggers shutdown before the displayed percentage reaches zero. It is not a faulty cell; it is an uncalibrated gauge reading a new cell curve. Charge to 100%, let it discharge fully to auto-shutdown, then charge uninterrupted — after that cycle the gauge tracks the new cliff correctly and shutdowns at low percentage stop.