Most of those smoke detectors are old and already passed their 10-year-lifespan. People keep putting 9-volt batteries in them, but they shouldn't.

If you go look at modern smoke detectors, many-to-most, now have a non-replaceable battery for exactly that reason.

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wpm a day ago | parent | next [-]

I didn't have to look far to replace my combo CO/Smoke detector or do a ton of hard searching to find one that just took a 9-volt. The first two results on Amazon US for "smoke detector" take 9-volts.

	▲	Someone1234 a day ago \| parent [-]
		> The first two results on Amazon US for "smoke detector" take 9-volts. I did the same thing, and the first four results were Kidde and First Alert Smoke Alarms with non-replaceable 10-year lifespan batteries. It is likely because you recently purchased one, and Amazon has targeted your results based on your purchase history.

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sitzkrieg a day ago | parent | prev [-]

thank you for the information, i bought some in 2023 and they all take 9v batteries so i am quite surprised by this