Replace the batteries if you like but still write up the detectors. 99% of the homes I inspect I recommend either more detectors and or carbon monoxide detectors be installed.
I also now encourage all my clients to install lithium batteries in them, test them once a month and to replace their detectors every 5 years.
I try to get dinner started before I head outside. Once I’m back at the interior I clean the toilets and pull the hair balls from the drains, then it’s back to finishing the salad for dinner. It’s really the little things that get you repeat business.
I was told Lithium batters are not the best they work well up until the suddenly die.
Alkaline work well and the voltage slowly goes down they go into a chirp mode for a few days .
If giving out smokes/carbons, or replacing batteries led to liability, fire departments would have been sued out of existence years ago. I normally have a couple smokes in my truck for when I find a house without one. Of course it comes with the speech about how to take care of it and all…and it’s documented in my report. Either way, I’d rather be sued for giving one than hear about someone dying in a house fire in a house I inspected and knew there were no working smokes.