I replace old smoke detectors with the 10 year lithium battery ones that are built in. 

My electronic lock is on a 9V battery.

.$100/mo included in Rent will scare off the Tenants - you can't charge rent more than market Rent is...but you can bill them water/sewer if there are meters for each unit

For example, the tenant didn't replace a single light bulb or the tenant took the batteries out of the smoke alarm...it seemed it kept going off when they were smoking apparently.

However, with the normal wear and tear/ usage of the two main entry doors to the units foyer area, we have had more than 5 service calls on the locks (for batteries, lock mechanism not functioning, etc.) and both front door Locks have had to be replaced once already and I am thinking it is time to use a different Door Lock method. 

The Kidde Access Point is the best. https://www.amazon.com/Kidde-AccessPoint-001414-Co...Electronic locks are great, but you'll always want a spare in case the battery dies.

Great job 809 credit score. 12 hits on criminal record the worst being battery with intent to cause physical harm (3 counts total) and Burglary of a Dwelling.

The small town rumor is that dude is the dope man and he has a laundry list of small-time drug and some more significant battery convictions already.

In 2020, new homes in California will require them. http://www.jlconline.com/business/california-mandates-solar-panels-with-a-battery-option_o

I put in my lease that I will be replacing the furnace filter, batteries for smoke detector/CO detector, and inspecting the unit every 6 months.