Samsung Midas EB-L1H2LLU Replacement Battery 3.7V 4200mAh

Samsung Midas / SC-06D — 3.7V Li-ion Replacement Battery (EB-L1H2LLU)

This is a 3.7V, 4200mAh Li-ion replacement battery for the Samsung Midas and SC-06D smartphones. It carries OEM part numbers EB-L1H2LLU and EB-L1H2LLD and slots into these devices as a direct cell replacement. Total energy is 15.54Wh.

• Midas and SC-06D compatibility: Both models run the same 3.7V single-cell architecture with the same connector pinout and BMS handshake protocol. One cell covers both devices without hardware modification.
• Bench tested on actual hardware: We ran this cell through charge and load cycles on the Midas platform. The BMS communicated correctly with the charge IC, accepted a full charge without thermal flags, and held voltage under screen-on and modem load without dropping below the cutoff threshold.
• Fuel gauge recalibration on first use: After installing this cell, run one full discharge to automatic shutdown, then charge uninterrupted to 100% before re-enabling fast charging. The Midas fuel gauge IC calibrates its coulomb counter against the discharge curve of the new cell during this cycle. Skipping it causes erratic percentage readings for weeks.

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

This is a voltage cliff problem, not a capacity problem. The Midas fuel gauge IC still holds the discharge curve from the old, degraded cell. When a fresh cell with a different curve hits the same voltage point, the IC reads it as critically low and triggers an emergency shutdown before the cell is actually depleted. The fix is one complete discharge-charge cycle with fast charging off, which forces the coulomb counter to relearn the new curve. After that cycle, shutdowns before 15% should stop.

Midas not powering on after the replacement battery sat in storage

Li-ion cells self-discharge during storage. If this battery sat below 2.5V per cell before installation, the BMS enters lockout mode and blocks all charge current to prevent damage. The phone shows nothing — no charge screen, no vibration. Connect it to a 5V USB charger and leave it for 20–30 minutes without pressing the power button. The BMS needs trickle current to climb back above the lockout threshold, typically around 2.9V, before it will accept a normal charge or allow the device to boot.