My first set of lithium batteries in my small window sensors on ADT alarm systems lasted nearly 6 years and I had them all replaced in December 2020. One of the replacements is low now in less than 2 years. Also the sensor in my Smoke Detector went low in September and it was installed at the same time and I have replaced. ADT is coming Wednesday to replace the one sensor. I have never before this had any Lithium Battery go out in less the 2 years. Most other batteries I have in my home are alkaline and they last longer than that. Just wonder if anyone else has had that problem lately with Lithiums. Most lithiums last at least 3 years. I was told when I asked that the lithiums in the small window sensors lasted at least 5 years which they did. Anyone else had problems with this and should I get them to replace all the ones that were put in less than 2 years ago rather than pay a service charge if they have to keep coming out to replacing them. If they only replace one if another on goes out any time soon I will have them replace all of them. This is a pain in the ass.