What is wrong with lithium batteries in smoke detectors

Broadsword

On the basis that the smoke alarms and CO2 detector drive the dog mad if the battery goes flat and the alarm starts chirruping if we are out, I decided to replace the batteries with lithium on the basis that they claim a ten year life. The first to require replacement was in a smoke alarm. As the chirruping noise (to signify flat battery)did not cease we replaced the alarm thinking that was at fault. It came with a battery which we left in so immediate problem solved.

Now the CO2 detector has gone flat we did the same with the same result. The detector did not recognise the battery and continued with the flat battery sound. We used a different lithium cell than before but both are the standard two press terminal 9v type. This time we refitted the CO2 detector, rather than assuming it to be faulty, with a non lithium battery and it was fine, as expected. It tested perfectly on standard 9v cells.

So the culprit seems to be lithium cells. Has anyone else encountered this? Both detectors are maybe 4 years old, is it only newer ones that recognise lithium batteries?

forgotmyname

What brand of batteries are you using?

Checked the actual voltage?

Fake batteries? Where did you buy them?

keystone

Broadsword wrote: »

So the culprit seems to be lithium cells.

Boeing have found this out the hard way too!

Cheers

Myser

Ultralife are the recommended brand for smoke alarms.

Some lithium batteries have a slightly higher starting voltage than a standard 9V battery. This may cause some alarms to malfunction.

Check with the manufacturer if you can use lithium batteries in the alarms.

If they are rechargeable lithium batteries or cheap ones, you may have a problem using them.

evoke

I wouldn't use long life batteries in smoke detectors. The batteries should be changed every year and the alarm tested to ensure it works.

Trying to use batteries that might last 10 years is risking the avoidance of testing.

If you replace the batteries every year before the old batteries go flat and test the alarm then your original problem goes away.

Myser

Testing of the alarm and replacing batteries is exclusive. You should test the alarm on a regular basis and not just when the batteries are changed.

Some reputable brand alarm manufacturers supply their alarms with long-life lithium batteries installed.

There's nothing wrong with using long-life lithium batteries. They just cost a lot more. The alarm will still chirp when the battery reaches near the end of its life.

In any case, it is recommended that a smoke alarm is replaced every 10 years.

Broadsword

Thank you for very helpful comments. Myser, in particular, may have hit the nail on the head. The batteries are JCB in sealed packs and test at 10.55 and 10.90 (two different batteries) so maybe that counts as over voltage. Other comments about regular testing are well taken.

I am going to make a diary note to replace after 10 months so the dog does not get upset if we happen to be out.