HE50 Motorola Moto E4 Plus Compatible Battery 3.8V 4850mAh

Motorola Moto E4 Plus (XT1770 / XT1771 / XT1775) — 3.8V Li-Polymer Replacement Battery (HE50 / SNN5989A)

This is a 3.8V, 4850mAh Li-Polymer cell that replaces the original HE50 battery in the Moto E4 Plus. It fits the XT1770, XT1771, and XT1775 variants along with seventeen additional regional models that share the same battery bay and connector. If your phone shuts down unexpectedly, won't hold charge, or the battery has physically swollen, this cell is the direct hardware replacement.

• XT1770 / XT1771 / XT1775 platform fitment: These three variants share an identical battery bay, flex connector pitch, and BMS communication line. The same HE50 cell fits all of them without modification — no adapter, no re-pinning.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on an XT1775 unit. The BMS handshake completed on first connection, charge acceptance registered immediately, and the protection circuit tripped correctly at the low-voltage cutoff threshold.
• Fuel gauge recalibration on first cycle: After fitting this cell, disable fast charging in developer options and run one full discharge-charge cycle at standard rate. The Moto E4 Plus fuel gauge IC calibrates its coulomb counter against the cell's discharge curve on the first full cycle — skipping this step leads to inaccurate percentage readings for the first week of use.

Sudden shutdown at 20–30% on the Moto E4 Plus after a cell swap

The Moto E4 Plus uses a coulomb-counting fuel gauge IC that was calibrated to the original cell's internal resistance profile. A new cell has lower internal resistance, so the voltage-to-capacity curve doesn't match what the IC expects. Under high-draw conditions — mobile data, screen at full brightness, GPS active — the IC reads a voltage that maps to 20–30% on the old curve but is actually near the BMS low-voltage cutoff for the new cell. The phone cuts out because the BMS trips, not because the cell is empty. One complete discharge-charge cycle at standard charge rate resets the IC's reference point and eliminates this behaviour.

USB charging not detected after fitting the replacement cell

If the Moto E4 Plus shows no charging animation after the new cell is installed, the BMS on the replacement cell may be in lockout from a low state of charge during transit — cell voltage can drop below 3.0V in storage. Connect the phone to a 5V/1A wall charger (not a PC USB port, which may not supply enough current to wake the BMS) and leave it for 20 minutes without pressing the power button. The charge IC needs a trickle current to bring the cell above the BMS re-enable threshold of approximately 3.0V per cell before normal charging resumes.