About this replacement
Hisense Mira II / EG980 Series — 3.8V Li-Polymer Replacement Battery (LP38250)
This is a 3.8V, 2500mAh (9.5Wh) lithium-polymer cell built to the LP38250 specification. It fits the Hisense Mira II, T978, EG980, and T980 smartphones. When the original cell degrades and can no longer hold voltage under load, this swap restores normal operation.
- Mira II / EG980 platform fit: The Mira II, T978, EG980, and T980 share the same battery bay dimensions and connector pinout. All four models use the LP38250 cell at 3.8V nominal, so one part number covers the group without modification.
- Bench tested on actual hardware: We ran this cell through a full charge-discharge cycle on the EG980 and confirmed the BMS accepted the cell without triggering a fault flag. Charge current stepped down correctly at the 4.35V cutoff, and the protection circuit tripped cleanly at the low-voltage threshold.
- Fuel gauge recalibration on first use: On first use after installation, disable fast charging and run one complete discharge-charge cycle at standard rate. This gives the fuel gauge IC a clean reference curve for the new cell before high-current charging begins on an uncalibrated coulomb counter.
Sudden shutdown at 20–30% on the Mira II after a cell swap
A new lithium-polymer cell has a slightly different voltage-discharge curve than the aged cell the fuel gauge IC was trained on. When the phone's processor or modem pulls a short burst of high current — screen wake, LTE handoff — the new cell's voltage dips sharply at that part of the curve. The OS reads the dip as a critical low-voltage event and shuts down, even though the state-of-charge counter still shows 25%. One full discharge-to-shutdown followed by an uninterrupted charge to 100% resets the coulomb counter and eliminates most premature shutdowns.
USB charging not initiating on the first cycle after fitting the LP38250
If a replacement LP38250 cell sat in storage and dropped below roughly 3.0V, the BMS enters a lockout state that blocks normal charge handshake on the USB port. The phone appears completely dead and the charger reports no load. Connect the phone to a 5V/1A USB source — not a fast charger — and hold the power button for 15 seconds. This forces the BMS into a trickle pre-charge mode that brings the cell back above 3.2V, after which normal charging resumes automatically.