# The Facts About 10-Year Batteries **URL:** \ **Category:** Factual Questions\ **Created:** [November 30, 2022, 6:25pm UTC](https://boards.straightdope.com/t/the-facts-about-10-year-batteries/975811 "2022-11-30T18:25:58Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![Jinx](https://avatars.discourse-cdn.com/v4/letter/j/c6cbf5/32.png) [@Jinx](https://boards.straightdope.com/u/Jinx)\ **Post date:** [November 30, 2022, 6:25pm UTC](https://boards.straightdope.com/t/the-facts-about-10-year-batteries/975811/1 "2022-11-30T18:25:58Z")
A question came up in the family: Many smoke alarms these days come with a 10-year battery. We know conventional batteries typically corrode in a year or so. Do these 10-year batteries also corrode in the same time as a conventional battery? Apparently not, I wager, but if not…why not? ---
**Author:** ![dolphinboy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dolphinboy/32/330_2.png) [@dolphinboy](https://boards.straightdope.com/u/dolphinboy)\ **Post date:** [November 30, 2022, 6:39pm UTC](https://boards.straightdope.com/t/the-facts-about-10-year-batteries/975811/2 "2022-11-30T18:39:09Z")
It may simply be that they are sealed better and won’t leak or corrode as quickly. I’m guessing you pay more for the 10-year battery. ---
**Author:** ![SmellMyWort](https://avatars.discourse-cdn.com/v4/letter/s/ea5d25/32.png) [@SmellMyWort](https://boards.straightdope.com/u/SmellMyWort)\ **Post date:** [November 30, 2022, 6:40pm UTC](https://boards.straightdope.com/t/the-facts-about-10-year-batteries/975811/3 "2022-11-30T18:40:36Z")
IME conventional alkaline batteries don’t “typically corrode in a year or so.” I think they tend to corrode if they are exposed to harsh environments, which would not include the inside of a modern house. ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [November 30, 2022, 7:55pm UTC](https://boards.straightdope.com/t/the-facts-about-10-year-batteries/975811/4 "2022-11-30T19:55:50Z")
Most 10-year batteries are Lithium Thionyl Chloride, and they are manufactured with a glass seal, so they rarely leak. ---
**Author:** ![naita](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/naita/32/5862_2.png) [@naita](https://boards.straightdope.com/u/naita)\ **Post date:** [November 30, 2022, 10:23pm UTC](https://boards.straightdope.com/t/the-facts-about-10-year-batteries/975811/5 "2022-11-30T22:23:31Z")
> [@Jinx](#): > > We know conventional batteries typically corrode in a year or so. I think your battery knowledge might be 50 years out of date … ---
**Author:** ![bump](https://avatars.discourse-cdn.com/v4/letter/b/7c8e57/32.png) [@bump](https://boards.straightdope.com/u/bump)\ **Post date:** [December 1, 2022, 6:52pm UTC](https://boards.straightdope.com/t/the-facts-about-10-year-batteries/975811/6 "2022-12-01T18:52:15Z")
Alkaline 9v batteries have a roughly 5 year storage life, and are good for roughly a year in a smoke detector. The 10 year batteries are almost certainly lithium batteries of some stripe- I sort of doubt they’re just regular old Energizer Lithiums- they’re probably quite a bit larger to support 10 years of use. The trick to the 10 year battery smoke detectors is that the detectors themselves have a 10 year service life as well- if they make them have a 10 year battery, then you kind of kill two birds with one stone- the consumer replaces the detector when it is necessary AND there’s no need for them to replace the battery annually. Win-win, even if it costs a bit more up front (but it’s for 10 years of use, so how much is that extra cost actually?) But fundamentally, they use a different battery chemistry that doesn’t involve the outer shell like the older zinc-carbon did (the batteries notorious for leaking), so they’re going to be fine for that duration. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [December 1, 2022, 10:52pm UTC](https://boards.straightdope.com/t/the-facts-about-10-year-batteries/975811/7 "2022-12-01T22:52:38Z")
I have a cheap wristwatch around somewhere that’s 20 years old, never had the battery replaced, and still works (though the numbers are rather faded). The only reason I don’t wear it any more is the band didn’t last nearly that long. ---
**Author:** ![crazyjoe](https://avatars.discourse-cdn.com/v4/letter/c/f14d63/32.png) [@crazyjoe](https://boards.straightdope.com/u/crazyjoe)\ **Post date:** [December 2, 2022, 12:10am UTC](https://boards.straightdope.com/t/the-facts-about-10-year-batteries/975811/8 "2022-12-02T00:10:27Z")
I just returned 2 2-packs of smoke alarms to Costco supposedly with 10 year non-replaceable batteries. They all started a low battery chirp (at 3am of course) after 1 year.