Vodafone Simply 1 Replacement Battery 3.7V 750mAh

Vodafone Simply 1 / Simply 2 (VS1, VS2) — 3.7V Li-ion Replacement Battery

This is a 3.7V, 750mAh Li-ion cell for the Vodafone Simply 1, Simply 2, VS1, and VS2 handsets. These are basic mobile phones built for straightforward calling and messaging. It replaces the original cell when the phone no longer holds charge through a standard day of use.

• Simply 1, Simply 2, VS1, VS2 platform fit: These four models share the same battery bay dimensions (53.80 × 33.70 × 5.80mm), connector pinout, and charge IC signalling. Swapping between any of them uses the same cell without modification.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the VS2 platform. The BMS accepted charge current correctly, voltage held steady under active call load, and the protection circuit tripped cleanly at the low-voltage threshold without hard-locking the board.
• Fuel gauge recalibration on first install: After fitting this cell, run one full discharge to automatic cutoff, then charge uninterrupted to 100% before normal use. The phone's fuel gauge IC is calibrated against the old cell's discharge curve — one complete cycle rewrites that reference against the new cell.

Sudden shutdown at 20–30% on the Vodafone Simply series

This is the most common symptom after a cell ages past 18–24 months. The fuel gauge IC reports 20–30% remaining, but the cell's internal resistance has climbed high enough that it cannot sustain voltage when the GSM radio fires a transmission burst. Voltage drops below the BMS cutoff threshold in milliseconds — the phone shuts off before the OS can log a low-battery warning. A new cell with lower internal resistance eliminates the sag. After fitting, run one full discharge cycle so the fuel gauge IC recalibrates its cutoff map to the new cell.

Phone shows wrong battery percentage after fitting a new cell

The fuel gauge IC on these handsets uses a stored discharge curve from the original cell to estimate state of charge. A new cell has a different impedance profile, so the percentage reading drifts — often jumping or reading full when the cell is not. This is not a fault with the replacement cell. Discharge the phone fully until it shuts itself off, then charge to 100% in one uninterrupted session. That single cycle gives the coulomb counter enough data to rebuild an accurate curve against the new cell's actual voltage profile.