Roost Smart devices are not rechargeable. However, the two-piece design of the Roost battery and Roost garage door sensor includes a replaceable primary lithium battery. When the devices power gets low, you can simply replace the battery pack for an additional 3-5 years of life.
You can purchase replacement battery packs online in the Roost store.
Please also see our Help Center article: Will I need to set up my Roost device after replacing the batteries or power unit?
The Roost leak detector is not able to recharge it's AAA batteries.