Emporia Elson EL380 Replacement Battery 3.7V 550mAh

Emporia Elson EL380 / EL399 / EL470 — 3.7V Li-ion Replacement Battery (BTY26158ELSON/STD)

This is a 3.7V Li-ion cell rated at 550mAh (2.04Wh), matching the OEM spec for the Emporia Elson EL380, EL399, and EL470. These are compact feature phones aimed at straightforward, low-data use — calls, texts, and basic navigation. The BTY26158ELSON/STD part number maps directly to all three models, which share the same battery bay dimensions and connector pin-out.

• EL380, EL399, and EL470 compatibility: All three Elson variants use the same 43.00 × 39.46 × 3.69mm cell footprint and a shared BMS handshake protocol. Swapping between these models carries the same cell — no connector or voltage rail differences.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the EL470 platform. The BMS accepted the cell without fault flags, held the 3.7V nominal rail steady under call-active load, and did not trigger overcurrent cutoff during peak GSM transmission bursts.
• Fuel gauge recalibration on first install: After fitting this cell, run one full discharge to auto-off, then charge uninterrupted to 100% before normal use. The phone's fuel gauge IC was calibrated against the original cell's discharge curve — one full cycle resets it against the new cell and stops percentage jumping.

Why the Elson EL380 shuts off suddenly at 20–30% after a battery swap

The EL380 uses a basic coulomb-counter fuel gauge that retains the old cell's discharge curve in memory after a swap. When the new cell's actual voltage drops below the phone's shutdown threshold — typically around 3.4–3.5V under GSM transmit load — the phone cuts out even though the displayed percentage still reads higher. This is a voltage cliff, not a capacity problem. The fix is one full discharge-to-zero cycle followed by a full uninterrupted charge, which forces the fuel gauge to re-map against the new cell's actual curve. After that single calibration cycle, shutdowns at false percentages stop.

Phone feels warm near the battery compartment on the first few charges

A new Li-ion cell has slightly higher internal impedance than a cell that has been through several charge cycles. The charge IC compensates by pushing a steadier current into higher resistance, which generates more heat at the cell surface during the first two or three charges. This is normal and self-correcting — impedance drops as the cell's electrolyte settles. If warmth persists beyond the third charge or the phone becomes hot to touch, check that the battery contacts are fully seated and the cover is not trapping heat against the cell.