AT&T EABF22206A Replacement Battery 3.85V 3600mAh

AT&T Motivate 3 — 3.85V Li-Polymer Replacement Battery (HE401)

This is a 3.85V, 3600mAh Li-Polymer battery for the AT&T Motivate 3 smartphone, using OEM part number HE401. It fits devices listed under model code EABF22206A. Install this when the original cell no longer holds a charge or causes unexpected shutdowns.

• Motivate 3 / EABF22206A compatibility: Both model identifiers share the same battery bay dimensions, connector pinout, and BMS handshake protocol. The HE401 part number covers the full production run of this device without hardware variation between units.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on a Motivate 3 unit. The BMS accepted the handshake without error flags, and the charge IC ramped current normally through CC and CV phases to full termination.
• Fuel gauge recalibration on first install: On first use after installation, disable fast charging and run one complete discharge-to-charge cycle. This lets the fuel gauge IC map the new cell's discharge curve before the coulomb counter locks in its reference points — skipping this step causes erratic percentage readings for the first several days.

Sudden shutdown at 20–30% on the Motivate 3 after a cell swap

The Motivate 3 fuel gauge IC retains the discharge curve from the old, degraded cell after a swap. When the new cell hits the voltage range the old curve mapped as 20–30%, the gauge can misread remaining capacity and trigger a low-voltage protection shutdown. The phone cuts power even though usable charge remains in the cell. One full slow-charge cycle forces the coulomb counter to rebuild its reference against the actual new cell chemistry.

USB-PD fast charge not activating on first cycle after replacement

The Motivate 3 charge controller runs a handshake check on the first session with a new battery BMS. If the BMS responds outside expected timing on that first cycle, the controller defaults to standard 5V charging and does not negotiate higher voltage. This is not a fault — it clears after the first complete charge cycle reaches 100% termination. On the second charge session, fast charging resumes at full negotiated current.