I don't mind the chirps but I do often have huge problems finding out which fire alarm has a low battery - as some of our ceilings are (I think) 14ft going up and down a ladder multiple times isn't a lot of fun...

[A few years back our neighbouring apartment had a nasty fire - so I went out and bought a lot of fire alarms, fire blankets etc. - we weren't at much risk as our walls are about 1m thick sandstone. However, it did mean I ended up replacing all of the batteries in the "new" alarms at roughly the same time.]