iDO SP70A S600 Replacement Battery 3.7V 2400mAh

iDO S600 Series — 3.7V Li-Polymer Replacement Battery (SP70A)

This 3.7V, 2400mAh Li-Polymer battery replaces the OEM SP70A cell in the iDO S600, S601, and S630 smartphones. It restores power to a phone that no longer holds a charge or fails to power on due to a degraded original cell. Capacity is 8.88Wh — matching the stock specification.

• S600, S601, and S630 compatibility: All three models share the same battery bay dimensions, connector pinout, and BMS handshake protocol — the SP70A part number covers the full run of this hardware revision.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the S600 platform. The BMS accepted the cell without fault flags, and the charge IC reached termination voltage cleanly at 4.2V.
• 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 map its coulomb counter against the new cell's actual discharge curve before high-current charging begins on an uncalibrated cell.

Sudden shutdown at 20–30% on the replacement cell

This happens because the fuel gauge IC is still running the discharge curve it learned from the old, degraded cell. When the new cell hits a steeper-than-expected voltage drop under modem or screen load, the phone interprets it as a critical low-voltage event and cuts power. The reported percentage at shutdown is meaningless until the IC recalibrates. Run one full drain — screen on, no charger — down to automatic shutdown, then charge uninterrupted to 100% to reset the curve.

Phone won't power on after the SP70A sat in storage

Li-Polymer cells self-discharge during storage. If the cell drops below approximately 2.5V, the BMS enters lockout mode and blocks current flow to protect against unsafe charging of a deeply discharged cell. Plugging in a charger appears to do nothing — the phone shows no charging indicator. Connect to a 5V USB-A charger (not USB-PD) and leave it for 20–30 minutes without pressing the power button; the BMS trickle-charges the cell back above the lockout threshold, after which normal charging resumes.