EB575152VU Sprint Epic 4G Replacement Battery 3.7V 1250mAh

Sprint Epic 4G — 3.7V Li-ion Replacement Battery (EB575152VU)

This 3.7V, 1250mAh Li-ion cell replaces the original battery in the Sprint Epic 4G smartphone. It fits directly into the battery bay and connects via the same three-contact strip as the OEM unit. Also cross-references as EB575152VA, EB575152LA, and EB575152LU.

• Epic 4G battery bay fit: The Epic 4G uses a specific contact layout and BMS handshake tied to the EB575152 cell family. This replacement matches that contact geometry and communicates correctly with the phone's charge IC — the device recognises the cell and proceeds through its normal charge curve without throwing a fault.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the bench with the fuel gauge IC active. The BMS held the charge cutoff at the correct upper threshold and did not trigger premature low-voltage lockout during the discharge sweep.
• Fuel gauge recalibration on first use: After installing a new cell, disable any power-saving fast-charge shortcuts and run one full discharge-to-charge cycle before normal use. The Epic 4G's fuel gauge IC was calibrated to the old cell's discharge curve — one clean cycle lets it remap against the new cell before the coulomb counter begins reporting accurately.

Sudden shutdown at 20–30% on the replacement cell

This is a voltage cliff issue, not a capacity issue. Under modem load or a screen-on burst, the cell's terminal voltage drops faster than the fuel gauge IC expects at that state of charge — the phone hits its minimum cutoff voltage and shuts off even though the percentage still reads 20–30%. The old fuel gauge calibration curve doesn't match the discharge profile of the new cell. One full discharge cycle — letting the phone run down to auto-off and then charging uninterrupted to 100% — resets the coulomb counter and corrects this. After calibration, expect the shutdowns to stop occurring above 10%.

Phone won't power on after the battery sat discharged in storage

If the cell dropped below approximately 2.5V during storage, the BMS enters a lockout state and blocks normal charging current to protect the cell. The phone won't respond to the power button or show a charging indicator. Connect it to a charger and leave it untouched for 20–30 minutes — the charge IC will deliver a trickle current below the BMS threshold and slowly recover the cell voltage. Once the cell climbs back above 2.8V, the BMS releases and normal charging resumes. If the phone still shows no response after 45 minutes on charge, the cell may have dropped below recoverable voltage.