Emporia Elson ESL808 Replacement Battery BTY26152 3.7V 700mAh

Emporia Elson ESL808 — 3.7V Li-ion Replacement Battery (BTY26152)

This is a 3.7V Li-ion cell rated at 700mAh (2.59Wh), built to the same footprint as the original BTY26152. It fits the Emporia Elson ESL808 smartphone. Swap it when the original cell no longer holds enough charge to get through normal daily use.

• Elson ESL808 fit: The ESL808 uses a compact 52.28 × 40.37 × 5.84mm cell with a low 3.7V nominal rail. The BTY26152 connector and PCB tab layout match the OEM spec directly — no adapter or modification needed.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the ESL808 platform. The BMS accepted the charge handshake on first connection, held voltage above the modem load threshold, and did not trigger low-voltage cutoff prematurely.
• Fuel gauge recalibration after install: On first use, disable any fast-charge mode and run one complete discharge-to-charge cycle at standard rate. This lets the fuel gauge IC map its coulomb counter to the new cell's actual discharge curve before fast-charge current is applied to an uncalibrated cell.

Sudden shutdown at 20–30% on the Elson ESL808 after a cell swap

This is a voltage cliff issue, not a capacity defect. When the fuel gauge IC still holds the discharge curve of the old, degraded cell, it misreads remaining charge on the new cell. Under modem or screen load, the phone pulls current the gauge didn't account for, the cell voltage drops sharply, and the protection circuit cuts power. One full discharge-charge cycle at standard rate resets the coulomb counter and eliminates the premature cutoff.

Phone won't power on after the BTY26152 sat in storage

Li-ion cells self-discharge slowly in storage. If the cell voltage drops below approximately 2.5V, the BMS enters lockout mode and blocks charge input to prevent damage to an over-discharged cell. The phone will appear completely dead — no charge indicator, no boot. Connect a known-good charger and leave it for 15–20 minutes without pressing the power button; most BMS circuits on this class of cell include a trickle-recovery path that will bring the cell up to a safe voltage before normal charging resumes. If voltage recovers to 3.0V or above, the phone will boot normally.