Lenovo S930 BL217 Compatible Battery 3.7V 2300mAh

Lenovo S930 / S939 Series — 3.7V Li-ion Replacement Battery (BL217)

This is a 3.7V, 2300mAh Li-ion replacement cell for the Lenovo S930, S938T, and S939 smartphones. It uses OEM part number BL217 and fits directly into the battery bay on all three models. Install it when the original cell no longer holds charge or the phone shuts down unexpectedly under load.

• S930, S938T, and S939 compatibility: All three models share the same battery bay dimensions, connector pinout, and BL217 BMS handshake. The charge IC on each device reads the same NTC thermistor response, so no model-specific firmware flag blocks the cell.
• Bench tested on actual hardware: We ran this cell through a full charge-discharge cycle and confirmed the BMS communicated state-of-charge correctly with the host device. Charge termination triggered at 4.2V with no overrun.
• Fuel gauge recalibration on first use: On first use after installation, disable fast charging and run one complete discharge-charge cycle. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging pushes current into an uncalibrated register.

Sudden shutdown at 20–30% on the replacement cell

The S930's fuel gauge IC stores a discharge curve calibrated to the original cell. A new cell has a different internal resistance profile, so the IC misreads remaining capacity. When the modem or screen draws peak current, the cell voltage sags below the cutoff threshold even though the displayed percentage looks healthy. One full discharge-charge cycle rewrites the coulomb counter baseline and corrects this behaviour. After that cycle, shutdown should not occur above 5–8%.

Phone won't power on after the replacement cell sat in storage

Li-ion cells self-discharge in storage. If the cell dropped below 2.5V per cell, the BMS trips into lockout to prevent damage and the phone will not respond to the power button. Connect the phone to a wall charger — not a USB port — and leave it for 20–30 minutes without pressing anything. The charge IC trickle-charges the cell back above the BMS re-initialisation threshold, typically 2.9V, after which normal charging resumes.