About this replacement
Samsung SPH-M570 / Acclaim M920 — 3.7V Li-ion Replacement Battery (EB404465VA)
This is a 3.7V, 1000mAh Li-ion cell that replaces the original EB404465VA battery in the Samsung SPH-M570 and compatible models including the Acclaim M920 and Restore M570. It fits the same physical footprint — 64.85 × 43.76 × 4.19mm — and connects to the same charge circuit without modification. Voltage and capacity match the OEM specification exactly.
- SPH-M570, Acclaim M920, and Restore M570 compatibility: These models share the EB404465VA form factor, connector pinout, and 3.7V nominal voltage rail. One cell fits all without adapter or modification to the battery compartment.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on SPH-M570 hardware. The BMS accepted charge from the onboard charge IC without fault flags, and the protection circuit tripped correctly at the low-voltage cutoff threshold during deep discharge testing.
- Fuel gauge recalibration on first install: After fitting this cell, run one complete discharge to automatic shutdown, then charge uninterrupted to 100% before normal use. The SPH-M570's fuel gauge IC reads the discharge curve to build its capacity model — skipping this step produces erratic percentage readings for the first several days of use.
Sudden shutdown at 20–30% on the SPH-M570 after cell replacement
The SPH-M570 shuts down abruptly in the 20–30% range when the fuel gauge IC is still calibrated to the old cell's discharge curve. The new cell hits a voltage cliff under modem or screen load that the gauge didn't predict, and the protection circuit cuts output before the displayed percentage reaches zero. This is not a fault with the replacement cell — it is a calibration mismatch. One full discharge-to-shutdown followed by an uninterrupted charge cycle resets the coulomb counter against the new cell and eliminates premature cutoff. After recalibration, the gauge tracks the actual cell voltage and load response correctly.
Phone will not power on after the replacement battery sat in storage
Li-ion cells in storage self-discharge below 2.5V per cell, which triggers BMS lockout — the protection circuit opens and blocks both charge and discharge paths to prevent damage. The phone shows no response to the power button and no charge indicator when plugged in. Connect the device to a wall charger and leave it for 20–30 minutes without pressing anything — the charge IC trickle-charges the cell at a reduced current rate to bring it back above the BMS re-enable threshold, typically around 2.9V. Once the charge indicator appears on screen, the BMS has re-initialised and normal charging resumes.