Samsung Galaxy J1 EB-BJ100CBE Replacement Battery 3.85V 1850mAh

Samsung Galaxy J1 / SM-J100F Series — 3.85V Li-ion Replacement Battery (EB-BJ100CBE)

This is a 3.85V, 1850mAh Li-ion cell for the Samsung Galaxy J1 and Galaxy J1 4G smartphones, including SM-J100F and SM-J100FN variants. It replaces OEM part numbers EB-BJ100CBE, EB-BJ100CBZ, EB-BJ100BCE, and GH43-04412A. Install it when the original cell no longer holds enough charge to keep the phone through a normal day.

• Galaxy J1 SM-J100 platform fit: These J1 variants share the same battery bay dimensions, connector pinout, and BMS handshake protocol. The 55.00 × 48.50 × 5.10mm cell geometry and NTC thermistor line are consistent across the SM-J100 board revision, so one SKU covers the full range listed.
• Bench tested on actual hardware: We ran this cell on an SM-J100F unit and confirmed the BMS accepted the charge cycle without fault flags. The protection circuit responded correctly to low-voltage cutoff and the charge IC recognised the NTC signal without triggering a temperature error.
• Fuel gauge recalibration on first use: On first use after installation, disable fast charging and run one complete discharge-to-charge cycle at standard rate. This gives the fuel gauge IC time to map the new cell's discharge curve before high-current charging pushes current into an uncalibrated state.

Sudden shutdown at 20–30% on the Galaxy J1 after a cell swap

This is a voltage cliff issue, not a faulty cell. Under modem transmission bursts or screen-at-full-brightness loads, the J1's SoC demands short current spikes the fuel gauge IC cannot predict from a freshly installed cell. The gauge reports 25% remaining, but the cell voltage drops below the SoC's minimum rail faster than the counter expects, and the phone shuts off as a protection response. One full discharge-charge cycle at standard rate lets the coulomb counter recalibrate against the actual discharge curve of the new cell, and the shutdowns stop.

OS showing wrong battery percentage after replacement

The Galaxy J1 stores its fuel gauge calibration data against the old cell's internal resistance profile. When a new cell goes in, the coulomb counter is still reading against that old model, which causes the percentage display to jump or stall — commonly freezing near 50% or reading 100% while the phone is still charging. This is not a hardware fault. Drain the phone fully until it powers off on its own, then charge uninterrupted to 100% at standard rate. After one complete cycle, the fuel gauge IC writes a new baseline and the percentage display stabilises.