EB-BJ120CBU Samsung Galaxy J1 6 Replacement Battery 3.85V 2000mAh

Samsung Galaxy J1 2016 / SM-J120F — 3.85V Li-ion Replacement Battery (EB-BJ120CBU)

This is a 3.85V, 2000mAh (7.7Wh) Li-ion cell for the Samsung Galaxy J1 6, also sold as the Galaxy J1 2016 and J1 6 Duos 4G LTE. It replaces OEM part numbers EB-BJ120CBU, EB-BJ120BBE, EB-BJ120CBEGWW, and GH43-04560A. The cell fits the SM-J120F/DS and all variants in that family.

• SM-J120 series fit: Every SM-J120 variant uses the same 3.85V rail, identical 69.10 × 51.10 × 4.20mm footprint, and the same BMS connector pinout — that is why one cell covers the full J1 6 lineup including Duos and LTE models.
• Bench tested on actual hardware: We ran this cell in an SM-J120F/DS and monitored BMS handshake, charge acceptance, and cutoff behaviour. The protection circuit engaged correctly at both ends of the voltage window with no spurious trips under normal load.
• Fuel gauge recalibration on first use: On first installation, disable fast charging and run one full discharge-charge cycle before enabling high-current charging. This lets the fuel gauge IC map its coulomb counter to the new cell's discharge curve rather than the degraded curve it learned from the old battery.

Sudden shutdown at 20–30% on the Galaxy J1 6 after a cell swap

This happens because the fuel gauge IC still uses the voltage-to-capacity curve it built from the old, degraded cell. A fresh cell holds a steeper voltage cliff in the lower charge window, so the phone hits the hardware low-voltage cutoff before the OS percentage counter reaches zero. The modem radio and display together draw enough current to collapse cell voltage below 3.4V in milliseconds — faster than the fuel gauge can update. One complete discharge cycle down to auto-off, followed by a full charge, resets the coulomb counter against the new cell's actual curve.

Galaxy J1 6 not powering on after the replacement battery sat in storage

Li-ion cells self-discharge in storage, and if the cell shipped or was stored for several months, voltage may have dropped below the BMS lockout threshold — typically 2.5V per cell. When voltage falls that low, the protection circuit opens the output FET and the phone sees no battery at all, not a flat one. Connect the phone to a wall charger rather than a PC USB port, which delivers higher current to wake a locked-out BMS. Leave it on charge for 15–20 minutes before attempting to power on; once the BMS sees voltage climb above roughly 2.9V it will re-enable the output and the phone will boot normally.