Are batteries that can't power a smoke detector still useful?

November 4, 2015 8:07 AM

Can I stick them inside some other device, or should they just be tossed?

I remember reading ages ago that different devices had different power requirements. So, for example, an AA battery that you could no longer use in your toy car might still have enough juice for, say a remote control.

Where do I go to find that type of information? My keyword hunting is impaired today.

posted by Make Way for Ducklings! to Home & Garden (13 answers total)

I've been able to use batteries in a remote control that didn't work in another device. Try it and see.
posted by John Cohen at 8:11 AM on November 4, 2015

I power my wireless mouse on pretty much nothing but batteries I've taken out of other things.
posted by jacquilynne at 8:21 AM on November 4, 2015

First two answers have it. My remote control batteries are always batteries that were in something else originally.

My dad has a digital multimeter (probably not a worthwhile purchase unless you have other uses for it) and the man never throws out a battery if he thinks it still has a lick of power left in it.
posted by futureisunwritten at 8:26 AM on November 4, 2015 [1 favorite]

Best answer: Anecdotally speaking, AA batteries seem like the default for low-need devices, and devices that design for 9V batteries are more likely to require the full power than devices that are built for AAs. I can name several low-need AA devices, but futureisunwritten's suggestion of a multimeter is the only 9V I can think of.

In other words, I am very interested to see this list when somebody comes up with it.
posted by aimedwander at 8:53 AM on November 4, 2015 [1 favorite]

Smoke detectors are low power constant drain devices that are fairly voltage insensitive. I'd be really surprised if there is enough energy in them to power anything once they stop working in smoke detectors.
posted by Mitheral at 10:15 AM on November 4, 2015 [3 favorites]

Everyone should have a multi-meter. They come in handy.

If you do find they're not useful, they should be recycled properly, not simply thrown in the trash. Whoever collects your garbage or your local city government should have a website that explains how to do this. Or find a RadioShack / Best Buy / Home Depot.
posted by jeffamaphone at 12:02 PM on November 4, 2015

Best answer: So basically, alkaline and nimh batteries lose voltage as they get used up. Lithium ion batteries don't. So if your device strictly requires almost 3 volts then 2 AA batteries will work for a short time if they're alkaline or nimh (since the voltage will drop below 3 volts pretty fast as they undergo usage) but if you use lithium ion batteries (which don't experience a voltage drop as they discharge) then you can use them up until they're spent. So if it's a dead lithium-ion AA battery then you're out of luck, but if it's NiMH or alkaline then whip out a multimeter and measure the voltage.

(This is my layman's knowledge talking so take it with a grain of salt.)
posted by I-baLL at 12:28 PM on November 4, 2015

The effect of dying 9V batteries on certain fuzz (guitar) pedals is a thing to the point that people try to simulate it.
posted by Lorin at 12:28 PM on November 4, 2015 [1 favorite]

Ours go in the multimeter.
posted by pompomtom at 1:47 PM on November 4, 2015

Another multimeter advocate here who also rotates batteries down to remotes and mice. I bought the multimeter for a different reason, but I think it was around 10 bucks from Radio Shack, and I'm sure that it has easily paid for itself in the batteries I've saved.
posted by Room 641-A at 2:54 PM on November 4, 2015

(to clarify: I don't mean I test them with the multimeter... but that the multimeter takes 9v batteries)
posted by pompomtom at 8:00 PM on November 4, 2015

Response by poster: I found it! The key words seem to be cutoff voltage. The list is here: Popular Mechanics, 1994.

Looks like I can move the batteries to my AM/FM transistor radio. I guess that's good to know.

(Also, the article that linked to that list, which has more info.)
posted by Make Way for Ducklings! at 7:03 AM on November 5, 2015

Response by poster: Also, that was for AA batteries. Like aimedwander said, I couldn't find many devices that use 9V at all, other than the multimeter (which I should probably get).

This other Ask question suggests donating them. The other things that seem to come up often are clocks, walkie-talkies, and guitar effects pedals.
posted by Make Way for Ducklings! at 7:21 AM on November 5, 2015