Changing air filters, light bulbs and batteries is fine but you don't want inexperienced people trying to fix things because they can make it worse.One thing that may help is having a conversation with them about the situation.

Most of the smart locks on the market run off batteries, so no fear about a power outage (although the batteries could go dead, but most still use a regular key as a backup). 

Let may expect you to pay it even though normally all the lease requires is that you do not charge rent for the time they can occupy the unit.

As long as the batteries work you are good and don't need a key. 

Given AirBnB is all rating and reviews, I do not want the risk of someones phone being dead, the internet being down, or batteries being dead, etc.  

Locally We are adding Full solar with whole-home battery EV charging and Smart home compliance for the newest group of Renters who will pay extra for these features.

You can screen tenants and charge rent through that platform if needed.

Can buy for around $200 on Amazon.Reolink Outdoor 3G/4G LTE Mobile Cellular Battery Security Camera Reolink GoYou simply put in a sim card and download their app.

Anyway they store data on an SD card that you have to check manually, but it is inexpensive, battery operated, and easy to hide.

Clean common area and collect my washing machine quarters.6 months I change the batteries in the smoke detectors/CO, fire extinguisher inspection/charging6 months I do a plumbing inspection6 months I do a thermostat battery changeNovember I do a radiator bleed.None are done at the same time and I do a complete walk through when doing.My buildings are across from town hall and the police station.