EB-4L Digma E601hd Replacement Battery 3.7V 1700mAh

Digma E601hd — 3.7V Li-ion Replacement Battery (EB-4L)

This is a 3.7V, 1700mAh Li-ion cell built to replace the original EB-4L battery in the Digma E601hd smartphone. It fits the E601hd directly, restoring power to a phone that no longer holds charge or fails to power on. Capacity figure comes from the product specification, not an estimate.

• E601hd cell compatibility: The E601hd uses a single-cell 3.7V Li-ion pack with a low-current BMS matched to the phone's charge IC. The EB-4L replacement matches that voltage rail and connector pinout, so the charge IC recognises the cell and begins the standard CC/CV charge cycle without flagging an error.
• Bench tested on actual hardware: We cycled this cell through full charge and discharge on the bench, confirmed the BMS did not trip on modem-load current draw, and verified the charge IC accepted the cell on the first connection without requiring a manual reset.
• Fuel gauge recalibration after install: On first use after fitting this cell, disable fast charging if the E601hd supports it, then run one complete discharge down to automatic shutdown followed by a full charge. This lets the coulomb counter recalibrate its end-of-charge and end-of-discharge thresholds against the new cell's actual discharge curve.

Why the E601hd reports wrong battery percentage after a cell swap

The E601hd's fuel gauge IC stores a learned discharge curve from the original cell. When a new cell goes in, that stored curve no longer matches the actual voltage-to-capacity relationship of the replacement. The gauge reads voltage and maps it to a percentage using old data, so the number shown can be 10–20% off in either direction. One full discharge-to-shutdown cycle followed by a complete charge resets the coulomb counter and brings the percentage reading back in line with actual remaining capacity.

Sudden shutdown at 20–30% on the replacement cell

This happens when the cell voltage drops below the BMS cutoff threshold under load — typically when the modem or screen pulls current the resting-voltage reading suggested the cell could still supply. A fresh cell with an uncalibrated fuel gauge will show 25% remaining while the actual open-circuit voltage is already near 3.5V. Under modem transmit load, that drops fast and hits the 3.0V cutoff before the percentage reaches zero. Run one full calibration cycle first; if shutdowns continue after that, check that the charge IC is reaching 4.2V at end of charge before unplugging.