The device supports boost reverse power direction to deliver power from the battery to the system when the adapter is not present. During this mode of operation, the ACFET and BATFET both remain off. The reverse mode output voltage regulation is set in VSYS_REV register bits. The reverse mode also offers output current regulation via the R_{AC_SNS} resistor. This parameter is controlled by the IAC_REV register bits. The reverse mode operation can be enabled if the following conditions are valid:

1. SRN above 3.8 V.
2. DRV_SUP voltage within valid operating window (V_{DRV_UVP} < V_DRV < V_{DRV_OVP}.
3. VAC outside the ACOV / ACUV operating window, or V_VAC < V_{VAC_OK}, or V_VAC> V_{VAC_INT_OV}
4. Reverse mode operation is enabled (EN_REV = 1)
5. Voltage at TS (thermistor) pin is within range configured by Reverse Temperature Monitor as configured by BHOT and BCOLD register bits

While the reverse mode is active, the device sets the REVERSE_STAT bit to 1. Host can disable the reverse operation at any time by setting EN_REV bit to 0. The device disables the converter, and turns the BATFET on to connect the battery directly to the system.

The charger also monitors and regulates the battery discharging current in reverse mode. When the battery discharge current rises above the IBAT_REV register setting, the charger reduces the reverse mode power flow to limit the discharge current.

A minimum of 3.8 V is needed to start the reverse mode successfully. However, once already in reverse mode, the the VBAT side can be reduced up to 2.5 V before the reverse mode turns off.

Once a valid VAC voltage is detected for forward operation, the device automatically disables reverse mode (EN_REV = 0), turns on the ACFETs and proceeds to charge the battery if enabled.