The batteries last years in most cases and I have not had any break down issues.

Prior to my tenants moving in, I give them a welcome letter which also has the following information:- Copies of their lease agreement, and any other addendums they signed- The names and phone numbers to call to start utility service- Information on watering days (if applicable, because some of my properties are located in areas that can only be watered on certain days/times) and trash pickup days- Information on gardening service (if provided/applicable, I tell them who will be coming and on what days)- Location of furnace filters, size of replacements, and recommended changing intervals- Nearest schools- Information on renters insurance (I don't require it, but I give them info on it in case they choose to get it)- Location of the smoke detectors and carbon monoxide detectors, along with recommended changing intervals for the batteries- Any other unique information about the specific property/neighborhood itself that I feel is important for them to knowI also provide them USPS address change cards for their convenience since I figure they'll have a lot to be worrying about during their move.As far as the water heaters go, I don't really want them messing with it after I set it so I don't provide any specific information on it.

Retailers have until July 1, 2015 to meet the requirement for stocking only sealed-in, long-life battery smoke alarms.'

I think doing inspections more often is too invasive.We checked the smoke detectors and put in new batteries, checked for running toilets (runs the water bill up and we paid the water bill), checked plumbing for leaks, including under sinks, checked the window a/c unit to be sure it's not leaking where it could cause damage, checked to see if the heater and/or a/c units were working.We'd ask if they needed the pilot light turned on or off for the gas heater, depending on time of year (they can make a place too warm in summer).  

Currently I charge rent and a $100/month utility fee.

It's my opinion, the landlord can charge rent until she knew the tenant was gone. 

Make it part of your system to do an inspection every 6 months, where you check smoke detector batteries, filter, check for leaks, running toilets, etc.But, no, the appliances are your responsibility, unless you have a lease and state laws that allow you to make the tenant responsible.  

My understanding was that if you cannot double charge rent, so if she is paid up through May 30th and someone moves in on May 28th, you must refund two days rent to the old tenant.

In the future, make sure language in the lease addresses this.You want to avoid having a tenant work on your property for a few reasons: The work may be done poorly and you'll have to redo it; the tenant may become injured doing the work and bring a lawsuit against you; it muddies the waters of your  existing relationship.The most I allow my tenants to do is change out the smoke detector batteries if needed- even that is in the lease.Good luck!

We just checked smoke detectors, changed the batteries, checked carbon monoxide detectors, checked for plumbing leaks, checked for running toilets, leaking a/c unit, and asked if they had anything they needed fixed.