Smoke Detector Battery - The Joke Is On Me

[FI_RElater]

...actually, all the ionization detectors would contain a small amount of radioactive material (almost always polonium 210)

That's how they detect...radioactive material emits small amounts of charge, charge transfer to any smoke particulate... any current due to these charged particles is detected.... then "beep...beep.."

incidentally, the major reason for false alarm beeps at night is actually small spiders getting in them. That's why they recommend taking canned dust removal spray (not something that would leave a residue) to blow the spider and their threads/web from the device (as the web would also act like the smoke particles, be charged, and give a response... and since it's physically there it would recur)

[ I changed all mine this year... had partial basement finish on this house and saw the old ones were old; figured i'd get them all changed out and be good.
Used to be "contractor packs" had ten...now only six....
(so got three packs) and, of course, the connector rings are ...just..so..slightly different that they all have to be changed out also. fun times
Interestingly, at one of my old houses... the local fire department would actually come out to change your whole house (obviously, you needed to buy them and have them ready and, no they didn't come out when they went off chirping in the night... you had to request and they'd come out (as available) - - they wanted to insure residents had working detectors (and some of our old ones then had actually been recalled, the fireman doing the task said... not something that most homeowners would have looked for ]

[ncbill]

Here by code hardwired have to be replaced with hardwired or hardwired with battery backup.

I replaced my hardwired-only ones with hardwired with battery since in power failures for some reason the originals made noises that sounded like R2D2 being tortured.

I prefer to avoid 9V batteries given their low capacity & high cost, so with the last smoke detector that died I replaced it with a combination smoke detector/CO alarm that uses two AA batteries instead of a single 9V.

[Dash man]

I’ve been replacing mine with the smoke detectors that have a 10year lithium battery installed, so you don’t have to replace the batteries until it’s time to replace the whole thing. The combination smoke/carbon monoxide detectors still use regular batteries.

[homestead]

Quote:

Originally Posted by SecondAttempt Unplug and remove battery. Place under a couch cushion until morning. Try to sleep while every barely perceptiple chirp gets you more and more angry. When you finally give up on sleeping at 5 AM, take it outside and use a large rock or sledge hammer to beat it into submission. Ok, don't do the smashing part. Some of them contain radioactive materials you do not want to spread around.

What I do to silence the alarm in the early morning is turn the heat on or up in that room and go back to bed. Changing the battery the next day.
The warmer air helps the battery get through the night.

[EarlyandLate]

Like Sunset, I decided that replacing mine with the 10 year battery disposable ones was cheaper than continuing to feed 9v batteries to them. I have had mine for two years now and have been very happy with them. I may not be in this condo long enough to have to replace them.

[Walt34]

When mine go off they all go off so there's no telling which one has the dead 9v battery. So the only 2:00 AM solution is to remove the battery on all of them, turn off the breaker for the smoke alarms, then wait five-ten minutes for their capacitors to drain and stop the chirping. Don't ask how I know this.

BTW, the reason that the wee hours is their favorite time to go off is that most people turn the heat down overnight. When the battery is just about dead but not quite there yet, that reduction in temperature is just enough to reduce the voltage enough to set off the chirping.

[cbo111]

I had one go off during the peak of hurricane Ian. Winds were howling about 80mph. We were sitting around trying to maintain a calm sanity, when suddenly I hear a voice yelling "Fire, Fire, Fire." A smoke alarm was going off. I didn't even know the thing talked. I didn't smell smoke and decided it was not an emergency. So I dragged the ladder in from the garage and tried to reset. Naturally the squawking alarm is on the ceiling of the highest point in the front hallway, so I could barely reach it. No joy with a reset. Changed the AA batteries. Still yelling at me. So I removed the whole device to silence it. I may replace it or might not. My home has 8 fire/CO2 alarms which seems a bit excessive.

[imnontrad]

I heard recently that smoke detectors actually should be replaced every 10 years because the sensors wear out. How old is that alarm?

[vdesalvo]

Replace your detectors with Nest brand. Automatic self test ever month and sends you the information. When the battery expires (10year) it is time to replace the unit. Remember sensors have a life span.

[Jerry1]

Quote:

Originally Posted by imnontrad I heard recently that smoke detectors actually should be replaced every 10 years because the sensors wear out. How old is that alarm?

That is my understanding as well. It seems tied to the battery, but I don’t think the sensors last indefinitely.

[FI_RElater]

Quote:

Originally Posted by Jerry1 That is my understanding as well. It seems tied to the battery, but I don’t think the sensors last indefinitely.

As I mentioned upthread, ionization detectors use Po 210, which has a half life of 158 days. Only a small amount is put into the detectors; the alpha particles emitted are somewhat higher energy (and thus are effective in creating charged particles of anything from the fire source) but are non-penetrating (so don't create a hazard outside the plastic housing). There does need to be some effective amount to be useful; at some age (again, defined by the half-life) the detectors are depleted beyond any ability to create charges and thus can't detect an active fire. [ even replacing batteries at that point would be ineffective, but obviously if the battery was fully discharged it wouldn't be effective either]

[38Chevy454]

Another thing to do that helps your detectors, blow them out with compressed air or from a "duster can" type thing. Might have been mentioned back in replies? Dust builds up and can cause a false alarm, or can decrease sensitivity. Helps to extend the detector life some. But as mentioned, the detectors do lose sensitivity from radioactive decay and need replacement after many years. 10 years is a good schedule.

[Sunset]

Quote:

Originally Posted by vdesalvo Replace your detectors with Nest brand. Automatic self test ever month and sends you the information. When the battery expires (10year) it is time to replace the unit. Remember sensors have a life span.

At ~$115 each, these are pricey and considering a need 4 or 5 for the house, I'd rather buy the 10 year sealed battery ones for $15 made by First Alert, a company that has been making them for decades.
A savings of $400->$500.

[braumeister]

Quote:

Originally Posted by Sunset At ~$115 each, these are pricey and considering a need 4 or 5 for the house, I'd rather buy the 10 year sealed battery ones for $15 made by First Alert, a company that has been making them for decades. A savings of $400->$500.

I agree. Where I live, the code requires two for each bedroom (one just inside the door and one just outside). Then most people want them in other places as well, so the number can easily expand beyond that.

[steelyman]

I’ll be buying another of those 10-year First Alert detectors but for carbon monoxide, not smoke. My existing smoke alarms are wired w/9V batteries, ceiling-installed.

I was advised to not get the combination smoke/CO models because CO disperses more evenly in the room space (unlike smoke).

[Graybeard]

Quote:

Originally Posted by steelyman I’ll be buying another of those 10-year First Alert detectors but for carbon monoxide, not smoke. My existing smoke alarms are wired w/9V batteries, ceiling-installed. I was advised to not get the combination smoke/CO models because CO disperses more evenly in the room space (unlike smoke).

I don't understand why they'd combine smoke and CO in the same device. Smoke is hot and rises, CO is heavier than air and sinks. Put them on the ceiling and if CO collects to get that high you died a week ago. Put them near the floor and the room would need to be filled with smoke. I don't see how a combination device would work properly vs a smoke detector on the ceiling and a CO detector close to the floor and ignition source.

[ERD50]

Quote:

Originally Posted by Graybeard I don't understand why they'd combine smoke and CO in the same device. Smoke is hot and rises, CO is heavier than air and sinks. ...

That didn't sound right. You might be thinking of CO2 (Carbon Dioxide)? CO (Carbon Monoxide) is lighter than air. A quick search verified that.

https://cpisecurity.com/blog/is-carb...nd-other-faqs/

Quote:

Carbon monoxide is also known as the “silent killer” since it’s an odorless, colorless, and tasteless gas. It’s slightly lighter than air but not enough to rise to the ceiling in a room. Instead, it tends to disperse itself, mixing with the air and spreading throughout a space. These traits are what make CO so dangerous: it’s a poisonous, invisible gas that is undetectable to the nose or eye (hence the importance of CO detectors), and mixes into our normal safe air.

-ERD50

[RobbieB]

Yeah, lighter than air, should be mounted 2/3 - 3/4 to the ceiling.

[Graybeard]

Quote:

Originally Posted by ERD50 That didn't sound right. You might be thinking of CO2 (Carbon Dioxide)? CO (Carbon Monoxide) is lighter than air. A quick search verified that. https://cpisecurity.com/blog/is-carb...nd-other-faqs/ -ERD50

Quote:

Originally Posted by RobbieB Yeah, lighter than air, should be mounted 2/3 - 3/4 to the ceiling.

I'm shocked! I did Google this and you are right.

Here's the odd thing about this. When I walk out of the basement into the garage there is a drop of about 4-5", this was new construction and I wondered why both floors were not at the same level. I asked why and was told CO is heavier than air so any CO from the boiler just a few feet from the door into the garage or the cars would sink into that lower area. Now I wonder if it was in case the garage was flooded the water had to rise before it got into the basement.

I guess I better move my CO detector from about 8" off the floor to about 5-6' onto the shelves above!

[Telly]

I thought garage floors were lower, or curbed from the doorway into the house, to keep gasoline from a leaky gas tank from running into the house.