In addition to the built-in internal battery used for RAM backup, the TWDLCAA40DRF and TWDLCAE40DRF
compact base controllers are equipped with a battery compartment that can host a user-replaceable external battery.

Note, The external battery option provides extended backup duration to meet the needs for long-term backup for
specific applications.

Note, that for most applications, no external battery is required.

The TWDLCAA40DRF and TWDLCAE40DRF compact base controllers uses one 1/2 AA, 3.6 V, lithium battery to provide optional extended data storage duration of up to 3 years.

The external battery is not included with your Twido controller; you must purchase it. The part number is
TSXPLP01 for a single battery or TSXPLP101 for a pack of 10.