Can I still open my door if the batteries die?
Ultraloq U-Bolt Pro is powered by 4 X Alkaline AA batteries for up to 8,000 times access. That is to say, battery life is up to 1 year on an average use of 20 times access per day.
You will also get low battery alert via beeps, red LED flashing and notifications in the App when your Ultraloq can still be unlocked for hundreds of times, so you will have more than enough time to replace the batteries.
If the battery dead completely, you can just use the backup mechanical key or connect a power bank to the external micro-USB outlet to activate the lock from outside.