The procedure to unseal the gauge to FULL ACCESS mode is as follows:

1. Read the CONTROL_STATUS register and verify that the [FAS] bit is set and the [SS] bit is cleared, indicating that the battery is in the UNSEALED state.
2. Send the low-byte Full Access Key (the low byte is FFFF; the default Full Access Key is 0xFFFFFFFF).
3. Send the high-byte Full Access Key (the high byte is FFFF; the default Full Access Key is 0xFFFFFFFF).
4. Wait 100 ms.
5. Read the CONTROL_STATUS register and verify that the [FAS] and [SS] bits are cleared, indicating that the battery is in the FULL ACCESS mode. If the [FAS] bit is set, but the [SS] bit is cleared, then return to Step 2. In this state, the fuel gauge allows full access to data flash, commands, and the ability to update firmware.
6. Retry three times before stopping the sequence.