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). 

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

If the tenant is not and you have lost rent, reconditioning the unit costs, and eviction and legal costs, then unforseen capital repairs can put things over the top in a bad way.Not trying to scare or anything you just need to go into the purchase with eyes wide open.

I put this on the front and rear doors, so there is a "backup entry" in case a lock misbehaves (or battery fails).

Napoleon Hill, Dale Carnegie, Gitomer, Rich Dad/ Poor Dad, Cashflow Quadrant, Trump's "Think Big & Kick ***" and "Think Like a Billionaire"), I'm working on the Trump University's "Real Estate 101", and I've got "The Art of The Deal", "The Best Real Estate Advice I Ever Recieved, and Kiyosaki's "The Real Book of Real Estate", plus about a dozen more on their way from Amazon (Thanks to a bunch of loose change and the CoinStar machine offering no 8.9% fee by choosing an Amazon gift card rather than cash)I WAS going to check out one of the local AREIA meetings last night but clearly last night just wasn't the night for me (got out of work late, had directions on my blackberry and the battery died, then my car overheated in traffic...

Batteries last several years, but if you swap them out once a year you'll never go dead.

For example I always own two cars, thus a flat tire or dead battery (or even a motor blowing up) is an annoyance, not an emergency. 

A battery, alternator, brakes and tires are much less than car payments.

The generated energy could charge a battery and possibly provide night lighting in the future.Maybe we'll do away with some of the lines by handling business right on site.