I was looking forward to hard wired smokes so we wouldn't have batteries to change in our high ceilings' date=' then I find out that they have battery backups. In the last house I built I got a call from the owner telling me that his batteries were chirping within one year of finishing the homes, and both batteries were over 20' high so he couldn't change them, I had to call my electrician to go out with a 16' ladder and stand on the top of the ladder, the second time they started chirping I took the batteries out of all the high ones as they started chirping. Let's face it they are still actuated by hard wiring and all the lower ones in the home still have battery backups.[/quote']You can always install a smoke detection "system" in accordance with the residential chapter of 72. Now wireless is approved in 72 so you could only have to replace a couple main batteries for the required secondary power supplies or connect to a home's generator that meets NFPA 110 and then only ladder work will be detector replacement when they fail sensitivity requirements..............