SoftBank 940SH Replacement Battery SHBCR1 3.7V 750mAh

SoftBank 940SH Series — 3.7V Li-ion Replacement Battery (SHBCR1)

This is a 3.7V Li-ion cell rated at 750mAh (2.78Wh), using OEM part number SHBCR1. It fits the SoftBank 940SH, DM005SH, 942SH, and 942SHKT handsets. Swap it in when the original cell no longer sustains a charge or causes unexpected shutdowns.

• 940SH series compatibility: These four models share the same battery bay dimensions, connector pinout, and BMS handshake protocol. The SHBCR1 cell meets the voltage rail and physical footprint — 38.18 × 37.21 × 5.30mm — that all four require.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on a 940SH unit. The BMS accepted the cell without error flags, and the protection circuit triggered correctly at low-voltage cutoff — no thermal events, no rejected charge cycles.
• First-cycle fuel gauge reset: On first use after installation, disable fast charging and run one full discharge-to-charge cycle. This lets the fuel gauge IC map its calibration points against the new cell's discharge curve before reporting accurate percentages.

Why the 940SH reports wrong battery percentage after a cell swap

The 940SH uses a fuel gauge IC that builds a charge model from repeated discharge cycles on the original cell. When you install a new cell, that learned model no longer matches the actual discharge curve. The IC reports percentage against stale calibration data, so the number on screen drifts from real capacity. One full uninterrupted discharge from 100% to automatic shutdown, followed by a full charge, resets the coulomb counter and aligns the gauge to the new cell.

Sudden shutdown at 20–30% on the replacement cell

This happens when the modem or display draws a current spike the cell cannot sustain at that state of charge. Voltage drops below the BMS cutoff threshold — typically around 3.0V — faster than the fuel gauge expects, so the phone cuts power before the displayed percentage reaches zero. It is not a faulty cell; it is the gauge reading high while the actual voltage is already at the cliff edge. Run two full discharge-charge cycles and the gauge recalibrates — shutdowns at false percentages stop once the coulomb counter tracks the real curve.