SFR Staraddict 2 Replacement Battery 3.7V 1500mAh Li-ion

SFR Staraddict 2 — 3.7V Li-ion Replacement Battery

This is a 3.7V Li-ion cell rated at 1500mAh (5.55Wh), built to fit the SFR Staraddict 2 and Staraddict II smartphones. The original cell degrades after 300–500 charge cycles, causing charge-holding problems and unexpected shutdowns. Swapping it restores normal power delivery to the phone's SoC, modem, and display subsystems.

• Staraddict 2 and Staraddict II fit: Both model names refer to the same hardware platform — same battery bay dimensions (64.60 × 43.95 × 5.10mm), same connector pinout, and the same charge IC on the motherboard. One cell covers both.
• Bench tested on actual hardware: We cycled this cell through charge and load discharge on the Staraddict 2 platform. The BMS communicated correctly with the phone's fuel gauge IC, and the charge IC accepted the cell without flagging a fault condition.
• Fuel gauge recalibration on first use: After fitting this cell, disable fast charging for the first full discharge-charge cycle. The fuel gauge IC is still calibrated to the old cell's discharge curve. One complete cycle at standard current lets it remap against the new cell before high-current charging begins.

Why the Staraddict 2 reports wrong battery percentage after a cell swap

The phone uses a coulomb counter in the fuel gauge IC to track charge state. That counter builds its reference model from cycles on the original cell. When you install a new cell, the IC has no calibration data for its specific discharge curve. It will report inaccurate percentages — sometimes reading 40% when the cell is nearly flat — until it completes at least one full discharge-charge cycle. After one full cycle at standard charge current, the fuel gauge resets its model and percentage readings stabilise.

Sudden shutdown at 20–30% on the replacement cell

This happens when the modem or display pulls a high current burst and the cell voltage drops sharply below the BMS cutoff threshold — even though the fuel gauge still shows charge remaining. It is a voltage-cliff failure, not a capacity problem. The fuel gauge is reading stored charge in coulombs, but the cell cannot hold its voltage rail under load at that state of charge. Run one full discharge cycle down to automatic cutoff, then charge to 100% — this resets the coulomb counter baseline and the shutdowns typically stop after one or two calibration cycles.