Bests & Worsts Reviews from Amazon

I bought these batteries because they were advertised "for smoke detectors." I thought great, why not invest in a 10-year battery to eliminate the once yearly smoke detector battery change process, as several of my smoke detectors are 15-20 feet up. So.. when I went to change the batteries, I found that these 9V batteries are NOT the same size as the average 9V battery. They are larger and they do not fit in the housing in my smoke detector. (Kidde Firex i4618 Interconnected Smoke Alarm) So.. be careful, as these are expensive and after spending $40 for 6 9-volt batteries, I find this out.. I am really disappointed and unfortunately it is too late to return them.