SRF Staraddict 2 Replacement Battery 3.7V 1750mAh Li-ion

SRF Staraddict 2 — 3.7V Li-ion Replacement Battery

This is a 3.7V, 1750mAh Li-ion cell for the SRF Staraddict 2 (also sold as the Staraddict II). It replaces the original battery when the phone no longer holds charge or shuts down unexpectedly. Dimensions are 64.60 × 43.95 × 5.10mm — confirm these against your original cell before ordering.

• Staraddict 2 and Staraddict II compatibility: Both model names refer to the same hardware generation. They share the same battery bay dimensions, connector pinout, and BMS communication protocol — one cell fits both.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the Staraddict 2 platform. The BMS handshake completed on the first cycle, charge current ramped correctly, and the protection circuit tripped as expected at low-voltage cutoff.
• Fuel gauge recalibration on first use: After fitting this cell, disable fast charging and run one full discharge-to-charge cycle before resuming normal use. The fuel gauge IC on this phone calibrates its coulomb counter against the cell's discharge curve — skipping this step causes erratic percentage readings and early low-battery warnings.

Sudden shutdown at 20–30% on the Staraddict 2

This is a voltage cliff problem, not a capacity problem. Under heavy load — cellular modem active, screen at full brightness — the cell voltage drops faster than the fuel gauge expects. The phone's protection circuit reads the voltage drop as a critical cutoff and kills power before the percentage display reaches zero. It happens on aged original cells and can also appear on a replacement cell whose fuel gauge IC has not yet calibrated to the new discharge curve. Run one full discharge cycle, then check if the cutoff point shifts. If it persists below 3.4V under load, the gauge IC needs a second full cycle to anchor its model.

Phone won't power on after the battery sat in storage

Li-ion cells that discharge below approximately 2.5V trigger a BMS lockout — the protection circuit opens and blocks current to prevent cell damage. Plugging in the charger may show no response at all. Connect the phone to a wall adapter rated at least 1A and leave it for 20–30 minutes without pressing the power button — most BMS circuits on this platform require a slow trickle before they re-enable the main charge path. Once the screen shows the charging indicator, the BMS has re-initialised and normal charging can proceed.