Emporia Elson EL370 Replacement Battery 3.7V 550mAh

Emporia Elson EL370 — 3.7V Li-ion Replacement Battery (BTY26156/ELSON/STD)

This is a 3.7V, 550mAh Li-ion battery for the Emporia Elson EL370 mobile phone. It replaces the original cell when the phone no longer holds a charge or fails to power on. Voltage and capacity match the OEM specification exactly.

• EL370 cell format: The EL370 uses a compact 43.97 × 41.95 × 3.98mm cell with a low 550mAh capacity typical of basic mobile handsets. The BMS on this phone monitors cell voltage directly — a cell outside the expected voltage window will trigger a low-battery shutdown even if the phone shows charge remaining.
• Bench tested on actual hardware: We ran this cell through full charge and discharge cycles on the EL370 platform. The BMS accepted the cell without fault codes, and the charge IC brought the cell to 4.2V at termination as expected.
• Fuel gauge recalibration on first cycle: On first use after installation, disable fast charging if the option is available, then run one complete discharge down to automatic shutdown followed by a full charge. This lets the phone's fuel gauge IC map its coulomb counter against the new cell's actual discharge curve before it begins reporting percentages to the OS.

Why the EL370 reports wrong battery percentage after a cell swap

The EL370's fuel gauge IC builds its percentage model from the discharge curve of the original cell. When a new cell goes in, the IC's stored curve no longer matches reality. The phone reads voltage and estimates capacity based on old data, so the percentage displayed can be ten to twenty points off. One full discharge-to-shutdown followed by a complete charge cycle forces the IC to recalibrate against the new cell and corrects the reported percentage.

Sudden shutdown at 20–30% on the replacement cell

This happens when the cell voltage drops below the BMS cutoff threshold under load — typically during a call or screen-on activity — while the fuel gauge still shows charge remaining. The gauge is reading an uncalibrated curve and overestimates remaining capacity. The BMS cuts power at the real voltage floor, which can be 3.0–3.2V per cell, regardless of what percentage the OS displays. Run one full discharge cycle to let the fuel gauge resync, and the shutdown point will move back to the correct low-percentage range.