HB5B2 Vodafone V830 Replacement Battery 3.7V 880mAh

Vodafone V830 — 3.7V Li-ion Replacement Battery (HB5B2)

This is a 3.7V Li-ion cell rated at 880mAh (3.26Wh), built to the same form factor as the original HB5B2 unit. It fits the Vodafone V830, VF830, and 830i. The cell measures 44.00 × 38.00 × 5.20mm and drops into the original battery bay without modification.

• V830 / VF830 / 830i compatibility: These model variants share the same battery bay dimensions, connector pinout, and BMS communication protocol. The HB5B2 and HB5B2H part numbers are interchangeable across all listed variants — the suffix difference reflects a minor revision to cell sourcing, not a hardware change.
• Bench tested on actual hardware: We cycled this cell through full charge and discharge on a V830 unit. The BMS accepted the new cell without tripping a lockout, and the charge IC stepped through its standard CC/CV profile without interruption.
• Fuel gauge recalibration on first install: After fitting this cell, run one complete discharge to auto-off before plugging in. The V830's fuel gauge IC uses a stored discharge curve from the old cell — one full cycle overwrites it. Skip this step and the percentage counter will drift early and report inaccurate figures for several cycles.

Why the V830 reports wrong battery percentage after a cell swap

The V830 uses a coulomb-counting fuel gauge IC that tracks charge relative to a learned cell curve. When you swap to a new cell, that stored curve no longer matches the new cell's actual voltage-to-capacity profile. The gauge continues reading against the old reference, so it can report 40% when the cell voltage is already near 3.5V. One complete discharge-charge cycle — down to shutdown, then a full charge to 4.2V — forces the IC to rebuild its reference map against the new cell.

Sudden shutdown at 20–30% on a freshly installed cell

This happens when the modem fires a high-current burst — during a call setup or data transmission — and the cell voltage sags below the BMS cutoff threshold instantaneously. The fuel gauge still shows 20–30% because it counts coulombs, not instantaneous voltage. A new cell that hasn't been broken in yet can show higher internal resistance, making this sag worse in the first few cycles. After two or three full cycles, internal resistance drops and the sag at load narrows — check that resting voltage holds above 3.7V between calls as a quick confirmation the cell is settling correctly.