Digma E601hd Replacement Battery 3.7V 1500mAh

Digma E601hd — 3.7V Li-ion Replacement Battery

This is a 3.7V 1500mAh Li-ion cell for the Digma E601hd smartphone. It replaces the original battery when the existing cell can no longer hold a usable charge. Dimensions are 65.80 × 43.90 × 5.10mm — confirm these against your existing battery before fitting.

• E601hd platform fit: The E601hd uses a standard 3.7V single-cell Li-ion architecture with a direct connector to the charge IC. This replacement matches that voltage rail and physical footprint so the charge IC sees a compatible cell from the first power-on.
• Bench tested on actual hardware: We ran charge and discharge cycles through the BMS at 3.7V nominal and confirmed the protection circuit trips correctly at the low-voltage cutoff. The cell accepted charge without fault flags on the first cycle.
• Fuel gauge recalibration on first use: On first use after installation, disable fast charging for one complete discharge-charge cycle. This lets the fuel gauge IC recalibrate against the new cell's discharge curve before high-current charging pushes current into an uncalibrated cell.

Why the E601hd reports wrong battery percentage after a cell swap

The E601hd uses a fuel gauge IC that builds a discharge model over multiple charge cycles. When you fit a new cell, the IC is still referencing the old cell's curve, which causes the percentage display to drift from the real state of charge. This is not a fault with the replacement cell — it is the IC catching up to the new cell's actual capacity. Run one full discharge down to auto-shutdown, then charge uninterrupted to 100% to reset the coulomb counter baseline.

Sudden shutdown at 20–30% on the new cell

This happens when the modem or screen pulls a current spike and the cell voltage drops below the BMS cutoff threshold before the fuel gauge registers it. The gauge shows 25% but the cell cannot sustain voltage under that instantaneous load. It is more common in the first few cycles before the fuel gauge IC has a calibrated curve for the new cell. After two or three full cycles the gauge tracks the actual voltage cliff accurately and premature shutdowns stop.