I have for many years had a pulse oximeter device to wear on a lanyard around my neck, to take readings of pulse and oxygen saturation levels as necessary. It is a very excellent device, which runs on a single AAA battery. Every now and then, depending on how much I use it, the battery must be changed.

One of those occasions arrived today. I retrieved a new Duracell AAA battery from my stash, removed the existing battery from its holder, as I have done dozens of times, and...... nothing. Hmmm, this is a new battery!

I selected another from my stash, a package of Duracells from Costco. Same result. The third one didn't work either, not weak, no sign of life.

I broke out my handy dandy Harbor Freight free volt meter to investigate. Each of the new Duracells show between 1.8-2.0 volts, unloaded. The old battery being replaced which still powers up the device shows below 1.5 volts, rapidly decreasing under test, about what a depleted battery would show, yet it lights up the lights on the oximeter.

Retesting each showed the same. Now this is strange. I carefully examined the device. Everything appears normal.

I had been careful to segregate the new batteries from the old one, to be certain the old one didn’t go back in the stash, among other things. Now, I started looking at these batteries. Sure enough, the old one was visually different from the new ones, in that the positive cap on the old one was a tiny bit higher than the positive caps on the new ones which were flatter and a tiny bit wider. The new batteries were not making contact in the device.

I have on hand some Harbor Freight batteries, free gifts, which I sometimes use. These have worked each time I have used them, but are much shorter lived than the Duracells. I put one of the HF batteries in the device and it worked normally.

The pack of Duracell AAAs is relatively new. I opened the pack last week to replace batteries in one of the TV remotes and those worked as expected. The battery in my pulse oximeter was from the prior pack, one of the last of those.

I examined the remaining batteries in the new pack and all were similar to the three I tried, and different in the same way as the battery from the older pack.

Is this a defective batch of batteries? Were the specs changed? Normal manufacturing tolerances?

This problem has come up before. It seems that there are some counterfeit batteries that are not made with the correct length. Perhaps yours are fake?

Duracell quality has been horrendous for years. I use Energizer's from Costco for Eneloop batteries.

There have been reports of counterfeit Duracell batteries and while I doubt Costco has any it might behoove you to look at that possibility. Especially with the physical difference.

The one site I looked at was pretty in depth on the issue even pointing out differences in packaging.

Again, while I doubt Costco is buying fakes, it might be worthwhile to look at that as a possibility.

quote:

Is this a defective batch of batteries? Were the specs changed? Normal manufacturing tolerances?

I'll bet that the battery mfr will say they are within normal manufacturing tolerances. Your device's mfr will probably disagree.
Maybe they are metric? That's what I blame for things not fitting.

quote:

Originally posted by shovelhead:
There have been reports of counterfeit Duracell batteries and while I doubt Costco has any it might behoove you to look at that possibility. Especially with the physical difference.

The one site I looked at was pretty in depth on the issue even pointing out differences in packaging.

Again, while I doubt Costco is buying fakes, it might be worthwhile to look at that as a possibility.

All my Duracells are from Costco, same packaging, etc. I had not considered counterfeits though. Maybe I should take them with me next trip to Costco.

Any links to the Duracell issues?

https://sigforum.com/eve/forums...935/m/2460071434/p/2

After an exchange of emails with Duracell's customer satisfaction people about the repeated failures I have had with their products lately, I suspect that at least some of their batteries are being made in foreign countries. A quick internet search showed these include India and China, where all good merchandise comes from.

I stopped using Duracell batteries about six months ago. I had issues with them swelling and leaking. Trashed 4 Mag lights I had. I switched to Energizers and have had no issues!

quote:

Originally posted by beltfed21:
I stopped using Duracell batteries about six months ago. I had issues with them swelling and leaking. Trashed 4 Mag lights I had. I switched to Energizers and have had no issues!

I lost two flashlights a few years ago due to swelling. Energizers were to blame, I switched to Duracells...

I think my swelling/failures were due to extreme low temperatures in the truck over winters. Everything that was indoors lasted as expected.

Everything is shit these days I've come to expect disappointment.

1.8-2v seems pretty healthy for a aaa alkaleak.

I'm just saying it could be possible there's an overvoltage protection circuit in there and if she sees over the normal shmormal 1.7 she trips and the thing takes a dump. Maybe the the damn things are TOO GOOD!

It's highly unlikely the threshold would be that low but all devices have variances and age, use, and environmental factors contribute to sometimes odd results.

Duracell, energizer, uncle bumblefuck house-brand, take your pick. You're gonna have trouble with any alkalines sooner or later. They just don't last, couple or four years maybe and toss em, used up or not. Seems as though duracell will replace products damaged by leakers. There is that. And also everyone will slip out a lemon that will ass your shit all up. Making batteries is complicated and factories are crankin em out like lucky charms, cheap as they can muster.

I dunno, try a aaa from one of your tv remotes.

Odd.

The IEC standard for AAA battery length gives a bit of tolerance (about 1mm) for overall length. They are supposed to be longer than 1.705 inches but no longer than 1.752 inches. If you have a micrometer or calipers you could measure the troubled ones and see if they're meeting spec. If not, you could probably return them.

That said, I would not envy having to sort through retail batteries for length. Not fun.

Many battery fittings are designed to address the length tolerance with a spring on the side where the flat side of the battery will go. The spring compresses when the battery goes in. When the battery is inserted and is released, the battery slides toward the positive terminal in the holder under spring force until contact is made.

The reason I say this is that there was one device of mine (a red-dot sight, if memory holds) where I needed to tweak the spring part because the tip had broken off over the years, making it too short to work reliably, so batteries weren't working. Any chance of that?

The workaround/fix was to bend the spring so it was long enough (it had extra metal). If that hadn't worked, I'd have put in another spring.

Maybe the battery tabs / springs inside your device have fatigued and aren't protruding as far or with as much force and the shorter batteries fail?

quote:

Originally posted by joel9507:
Odd.

The IEC standard for AAA battery length gives a bit of tolerance (about 1mm) for overall length. They are supposed to be longer than 1.705 inches but no longer than 1.752 inches. If you have a micrometer or calipers you could measure the troubled ones and see if they're meeting spec. If not, you could probably return them.

That said, I would not envy having to sort through retail batteries for length. Not fun.

Many battery fittings are designed to address the length tolerance with a spring on the side where the flat side of the battery will go. The spring compresses when the battery goes in. When the battery is inserted and is released, the battery slides toward the positive terminal in the holder under spring force until contact is made.

The reason I say this is that there was one device of mine (a red-dot sight, if memory holds) where I needed to tweak the spring part because the tip had broken off over the years, making it too short to work reliably, so batteries weren't working. Any chance of that?

The workaround/fix was to bend the spring so it was long enough (it had extra metal). If that hadn't worked, I'd have put in another spring.

This device does have a spring and the batteries are held in place quite tightly. The fitting for the positive end is somewhat constricted which is what drew my attention to that end of the batteries.

I do have calipers and those might allow me to measure the extent of the differences in the positive cap, if I get into discussions with Duracell. In the meantime, I just keep the HF batteries nearby. Those work very satisfactorily except being markedly short-lived, and they are free.

If you use metal calipers to measure the length of the battery you are going to have a direct short. Not good.

Put a piece of plastic over one end first. Subtract the thickness of the plastic from your measurement.

It sounds like the positive terminals on those Duracells weren't properly staked

I have no explanation for the weird high voltage, but this might be a good solution for your problem:

"Panasonic BK-4MCCA4BA Eneloop AAA 2100 Cycle Ni-MH Pre-Charged Rechargeable Batteries, Pack of 4"

www.amazon.com/Panasonic-BK-4M...teries/dp/B00JHKSMJK

quote:

Originally posted by Pipe Smoker:
I have no explanation for the weird high voltage, but this might be a good solution for your problem:

"Panasonic BK-4MCCA4BA Eneloop AAA 2100 Cycle Ni-MH Pre-Charged Rechargeable Batteries, Pack of 4"

www.amazon.com/Panasonic-BK-4M...teries/dp/B00JHKSMJK

I don’t consider the voltage of new batteries as weird, below 2.0 volts or so unloaded, especially when measured with a cheap voltmeter which can be but is not necessarily accurate, although I have had good experiences with them being on a par with much higher quality instruments.

It is physically difficult, if not impossible to measure the voltage in the circuit.

What hilarious is now they even have two style for high power or draw devices s or low draw devices

The last few times I have used Duracell 9v in my smoke detectors, the detectors continue to chirp.

I don't use the Duracells anymore.

Duracell = shit. Lost count of the number of remotes/flashlights/etc that leaking duracell batteries have killed. Energizer alkaline not much better. My go to now is Energizer Lithium. I've had one (1) leak but it didn't kill the device it was in. I call that a win.