Flush all the toilets.Check all the outlets and make sure the plugs stay in and that the outlets are functional (note any switched outlets)Test the smoke detectorsReplace batteries in digital thermostatsMake sure all light fixtures are working (we replace bulbs with leds).Make sure there are thresholds and not rough flooring edges.Make sure the HVAC system is functional.At your move-in walk through: show your tenant where the breaker box is and how to reset a tripped breaker.If you have old triple track or double track storms, show the tenants how to operate them.Show tenants how to relight the stove pilot light.Test the smoke detector in the tenants presence and show them how to replace battery if not a sealed unit.Show the tenant how to operate the thermostat.Remind the tenant to use the bath fan or to open the bath vent window.

Provide a safe and clean space for tenants, take pics when you install (every 10 years) or change batteries on smoke/carbon detectors, have them sign off on a movein doc that says windows open, smoke detectors, test.

@Roy N.yes I had to first rewire the battery system. 

changing out batteries is a hassle, weve always just used standard locks and kept the mains. 

HiWe recently asked for fire retrofit inspection of our building as it is needed for refinance, some of the units didn't pass audibility test, so we added wireless interconnected (battery-operated) alarms into the units, but fire inspectors require hardwired interconnected smoke alarms or horns to be added to each unit, which was estimated at over $5000 on electrician work.We asked them to check with fire marshall, who said wireless interconnected (battery-operated) alarms are alternative solutions, but fire inspector still disapproves what we did because they don't feel comfortable about battery-operated alarms. 

I would also point out that these numbers are national and each specific local real estate market will be affected differently depending on their past and present RE conditions.

They are suing for lose toilet, no screen on a window, non-working outlet in bathroom, pests, hall light not working (light bulb needed to be replaced) and non-functioning smoke alarm (they never replaced the batteries).

Renting out per bedroom instead of per unit can give 2-4 times more rental income.Partnering can be good getting into deals more smoothly however a partnership can go sour.Build your team of advisers who you can turn to with questions.Get the best management company to work with go to IREM.org search for ARM certified managers they passed a battery of tests.REIA clubs networking and meetup groups can be a great source of people, info and resources.

Batteries could go dead but if you are responsible you won't have an issue.

You might also consider well water and a solar/ battery setup as a backup plan.