Screenshot Level via Nena Farrell Screenshot Level via Nena FarrellThe Level Lock Pro can also sense if the door is open or closed without needing any additional accessories. I've opted not to; nobody needs to be able to voice-command my front door open. Power PlayPhotograph: Nena FarrellUnlike other smart locks that use bulky battery packs or several AA batteries, the Level Lock Pro uses a single CR2 lithium battery. The lock comes with a nonrechargeable CR2 battery made by Level, but you can replace it with any CR2 battery once it runs out. Where the previous Lock+ had about six months of battery life, the Level Lock Pro is expected to get about a year of battery life from a single CR2 battery.