About this replacement
ZTE Blade V8 / BV0800 — 3.85V Li-Polymer Replacement Battery (Li3927T44P8h786035)
This is a 3.85V, 2700mAh Li-Polymer replacement battery for the ZTE Blade V8 and BV0800 smartphones. It replaces OEM part number Li3927T44P8h786035 and matches the original cell's physical footprint at 77.00 × 59.28 × 3.30mm. Swap it in when the original cell no longer holds a charge or the phone shuts down unexpectedly.
- Blade V8 and BV0800 compatibility: Both models share the same battery bay dimensions, connector pinout, and BMS handshake protocol — a single cell SKU covers both variants without modification.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on a Blade V8 unit. The BMS accepted the cell without fault codes, charge termination fired correctly at 4.35V, and the protection circuit tripped as expected under simulated over-current conditions.
- First-cycle fuel gauge recalibration: On first use after installation, disable fast charging and run one complete discharge-to-charge cycle at standard rate. This lets the fuel gauge IC map its coulomb counter against the new cell's discharge curve before any high-current charging pushes current into an uncalibrated state.
Sudden shutdown at 20–30% on the replacement cell
This happens because the fuel gauge IC is still running the discharge curve it learned from the old, degraded cell. The new cell's voltage drops faster near the bottom of its curve than the IC expects, so the phone hits the hardware undervoltage cutoff before the reported percentage reaches zero. The fix is one full discharge-to-charge calibration cycle with fast charging off. After that cycle, the coulomb counter resets against the new cell and the shutdowns stop.
USB fast charge not working after battery replacement
On the first charge cycle after a cell swap, the charge IC on the Blade V8 may not negotiate the fast-charge protocol correctly with the new cell's BMS. This is normal — the IC runs a trickle pre-charge phase to verify cell health before stepping up current. Plug in using the original charger and leave it connected for a full charge without interruption. Fast charge typically re-engages correctly from the second cycle onward.