About this replacement
Vodafone V625 / VF625 — 3.7V Li-ion Replacement Battery (HB5A1H)
This is a 3.7V, 1000mAh Li-ion cell replacing the original HB5A1H battery in the Vodafone V625 and VF625 smartphones. It slots into the same battery bay and connects via the original ribbon contact. Voltage and capacity match the factory specification exactly.
- V625 and VF625 compatibility: Both model variants use the same 3.7V single-cell architecture, identical connector pitch, and share the HB5A1H part number — one cell fits both without any hardware modification.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on the V625 platform. The BMS accepted the charge handshake on first connection, current tapered correctly at top-of-charge, and cutoff triggered cleanly at the low-voltage threshold without spurious shutdowns.
- Fuel gauge recalibration on first use: After fitting this cell, disable any fast-charge mode and run one full discharge-to-charge cycle before normal use. The phone's fuel gauge IC is calibrated against the old cell's discharge curve — one complete cycle resets the coulomb counter to match the new cell's actual capacity curve.
Why the V625 reports wrong battery percentage after a cell swap
The V625 uses a fuel gauge IC that tracks charge state by counting coulombs in and out of the cell. When the original cell degrades, the IC quietly adjusts its internal model to match the shrinking capacity. Drop in a new full-capacity cell and that adjusted model is now wrong — the gauge reports 100% far earlier in the charge cycle than it should, and the percentage reading drifts through the day. One complete discharge from full charge down to automatic shutdown, followed by a full uninterrupted charge, forces the coulomb counter to rebuild its model against the new cell. After that single cycle, percentage accuracy returns to normal.
Sudden shutdown at 20–30% on the replacement cell
This happens when the modem or display draws a short high-current burst and the cell voltage dips below the BMS protection threshold — even though the gauge still shows charge remaining. It is a voltage-sag issue, not a capacity issue. A new cell with an uncalibrated fuel gauge will hit this cliff more often in the first few cycles because the gauge does not yet know where the real voltage floor sits under load. Run the recalibration cycle described above, then check: if shutdown still occurs below 25%, the BMS floor is set around 3.0V per cell and that behaviour is normal protection, not a fault.