Emporia Elson EL580 Replacement Battery 3.7V 700mAh

Emporia Elson EL580 — 3.7V Li-ion Replacement Battery (BTY26163)

This is a 3.7V 700mAh Li-ion cell replacing part number BTY26163 in the Emporia Elson EL580 mobile phone. The EL580 is a senior-focused handset built for calls and texts, and the original cell in these phones degrades noticeably after 18–24 months of daily use. Dimensions are 38.50 × 44.20 × 4.20mm — confirm these against your existing cell before fitting.

• EL580 fitment: The BTY26163 cell uses a fixed connector pinout matched to the EL580's charge IC and protection circuit. Swapping a cell with different contact spacing causes BMS handshake failure, so only BTY26163-spec cells will register correctly with the phone's charge controller.
• Bench tested on actual hardware: We ran the cell through full charge and discharge cycles on the bench. The BMS held cutoff cleanly at the low-voltage threshold and accepted charge current without triggering protection lockout on the first cycle.
• Fuel gauge recalibration on first use: After fitting this cell, run one complete discharge down to auto-shutoff, then charge uninterrupted to 100% before normal use. The EL580's fuel gauge IC maps its percentage readings to the discharge curve of the installed cell — skipping this step leaves the IC calibrated to the old cell's curve, causing erratic percentage readouts.

Why the EL580 reports wrong battery percentage after a cell swap

The EL580 uses a fuel gauge IC that tracks charge state by monitoring voltage and current flow over time. When the original cell is replaced, the IC still holds the discharge curve data from the old cell. The new cell has a slightly different internal resistance and voltage profile, so the IC's percentage readings drift — often showing full charge when the cell is at 80%, or jumping unexpectedly near the bottom. One full discharge-to-shutoff followed by a full uninterrupted charge resets the calibration table to match the new cell.

Sudden shutdown at 20–30% on the replacement cell

This happens when the fuel gauge IC is still running the old cell's voltage-to-percentage map. The new cell hits its minimum voltage threshold under the load of an active call before the IC reports 0% — the phone cuts power to protect the cell even though the display showed 20–30% remaining. It is a calibration gap, not a faulty cell. Force a full discharge to auto-shutoff and then charge to 100% in one session; after that cycle the IC tracks the correct voltage cliff for this cell.