SB2000 Schok Flip SC3218T Replacement Battery 3.8V 1700mAh

Schok Flip SC3218T / SC3218B — 3.8V Li-ion Replacement Battery (SB2000)

This is a 3.8V, 1700mAh Li-ion cell built to the SB2000 specification for the Schok Flip SC3218T and SC3218B flip phones. It powers the modem, display, and cellular radio stack. Drop it in when the original cell can no longer hold a usable charge through a normal day of calls and standby.

• SC3218T and SC3218B coverage: Both variants share the same battery bay dimensions, connector pinout, and 3.8V nominal rail — the SB2000 fits either without modification to the housing or charge circuit.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the SC3218T platform. The BMS accepted charge handshake on the first connection and held cutoff voltage correctly at both top and bottom of the curve.
• Fuel gauge recalibration on first cycle: On first use after installation, disable fast charging for one complete discharge-charge cycle. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging pushes current into an uncalibrated state.

Sudden shutdown at 20–30% on the replacement cell

This happens because the fuel gauge IC still holds the discharge curve from the old, degraded cell. When the new cell hits a voltage point the IC hasn't seen before, the OS reads the state of charge incorrectly and triggers a low-voltage shutdown. The modem radio draw accelerates the drop — it pulls a burst current the gauge doesn't anticipate. One full discharge-to-cutoff followed by a full uninterrupted charge resets the coulomb counter and resolves the early shutdown.

Phone reporting wrong battery percentage after cell swap

The fuel gauge IC on the SC3218T learns its reference curve from the installed cell over time. After a swap, the IC is still calibrated to the old cell's internal resistance and capacity profile, so the percentage display drifts — often reading 100% too quickly or dropping fast in the final 30%. Run two full cycles without interruption: discharge until the phone shuts off on its own, then charge uninterrupted to 100%. After the second cycle the gauge corrects to within a few percent of actual state of charge.