Does the 4iE have a battery backup?
Battery Backup for 4iE
There is no battery backup or capacitor in the 4iE, however there is internal memory.
Restoring Programming After an Outage
Periodically, the programming and the corresponding date/time are stamped to the 4iE’s internal memory. This is then overwritten when the next stamp takes place. When power is restored following a power outage, the device reverts to the most recent stamp taken.