Sign up ×
Home Improvement Stack Exchange is a question and answer site for contractors and serious DIYers. It's 100% free, no registration required.

One of my smoke detectors was chirping and when I removed the 9V battery, I found it was hot. In fact, it was making a 'cooking' sound.

Was it the smoke detector causing the battery to cook itself or was it a defective battery?

share|improve this question
I had a battery explode in one of my detectors. You got off lucky. – sww1235 Mar 26 at 17:24

3 Answers 3

up vote 5 down vote accepted

Wow- A smoke detector that could cause a fire..

It is very difficult to say

  • It could be a fault in the fire alarm- short circuit that caused the battery to heat up to a cooking point.

  • It could be a chemical fault in the battery where atmospheric pressure and chemical imbalances caused by some impurity during production caused the battery to heat up at a certain point of its life.

Either way

The safest option is to replace both and remove all doubt!

eg ever hear about the exploding iPods... :)

share|improve this answer
Now would be the time to buy the combo carbon monoxide & smoke detector that is required by code to go in houses. This site will tell your state require one, Smoke and Carbon Monoxide Alarms – lqlarry Nov 26 '11 at 20:30

I had this issue with a first alert BRK9120b that was 15 years old. After going through 2 or 3 batteries I changed the detector. All was fine until another detector in another bedroom started behaving the same way. At first thinking it was just the battery I changed it and the next day it was hot and dead again. I ordered 2 more detectors just to keep one hanging around as this seems to be a trend and I have 8 of these in my home. Fortunately after 15 years the detector hasn't changed all that much. The mounting holes are still the same but the bracket changed. It took an extra minute to change the bracket and the wire connector was still the same.

share|improve this answer

I just experienced the same problem. I discovered that I had installed the battery backwards. The smoke detector was chirping, so I removed battery (which was almost to hot to hold!), put another in out of same packet but in the correct orientation. No more chirping, and I have confirmed that the new battery is not overheating.

share|improve this answer
Have you confirmed that the detector is still working? If it drew enough current to cook ghd battery, it probably cooked the circuitry too. – keshlam Oct 28 at 18:41

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.