ever seen a Negative Voltage CR123A cell?

[rookiedaddy]

Have you ever seen a primary CR123A cell with Negative Voltage reading?

here's proof... errr... sort-of... :devil:

after a minute

this was use in 2 cells light >> NU-flaRE Rebel 90 oo:
I left it running until I can see a very very very dim lit from the LED... when I first pull the cells out, 1 cell reads 2.66V, while the cell at the tail end reads -0.26V... yup... -0.26V .
I thought I had the test lead in reversal... but nope... double checked, triple checked... It reads 0.26V when I reverse the leads.

After 10 hours of resting, the cell reads 1.16V.

 

[UberLumens]

Check the batteries in your meter, could cause an off reading.

That aside, you have an interesting cell there,

"this was use in 2 cells light "
what did the other one read after resting

 

[AW]

A -V reading means the CR123A has been reverse charged ( by the other CR123A that still has some juice left ). If the -V shows above 0.3-0.35, you might have been in trouble already.

 

[GLOCK18]

Does it show a Neg when set to 2v on the meter, might be the meter.

 

[rookiedaddy]

Check the batteries in your meter, could cause an off reading.

the 9V battery is a new Panasonic cell and it checks out ok.

what did the other one read after resting

the other cell at resting reads 2.68V.

Does it show a Neg when set to 2v on the meter, might be the meter.

yes, it does. and I'm sure it's not the meter...

A -V reading means the CR123A has been reverse charged ( by the other CR123A that still has some juice left ). If the -V shows above 0.3-0.35, you might have been in trouble already.

yes... i guess that's what happened... :sweat:

 

[TooManyGizmos]

~

The more important question is ...........

What was the volt reading of each of those cells BEFORE you fully drained em in your NU-flaRE Rebel 90 ?

Do you "Match" your cells for voltage before you exhaust them in multi-cell lights ?

You may be an accident waiting to happen .

Do you know better than to do that ? (or not)

~

 

[rookiedaddy]

~
The more important question is ...........
What was the volt reading of each of those cells BEFORE you fully drained em in your NU-flaRE Rebel 90 ?
Do you "Match" your cells for voltage before you exhaust them in multi-cell lights ?
You may be an accident waiting to happen .
Do you know better than to do that ? (or not)
~

Both cells when new (a couple of months back) reads 3.25V before put into the light.
The light runs out of regulation a day before (Sunday night) and I took a reading before the drain test (yesterday), both cells read 2.78V.
this is an interesting lesson learned and will be noted in my future experiments.

 

[TooManyGizmos]

~

It's very odd that one cell went from 2.78 to 2.66 ...while the other went from 2.78 to 0 and then to - volts.

You would think the other cell would have been much lower than 2.66 v. It must have to do with internal resistance.

It's always best not to run multi-cells down to very , very , very dim light .

You know what might happen . You might be sharing a room with Tim Taylor in the hospital .

~

P.S. (off topic) I pulled a 9v. alkaline cell from a chirpin smoke detector the other day .....
It read ... +12v on a DMM ........ explain that one ?

 

[HKJ]

P.S. (off topic) I pulled a 9v. alkaline cell from a chirpin smoke detector the other day .....
It read ... +12v on a DMM ........ explain that one ?

You need a new battery in the DMM.

 

[TooManyGizmos]

You need a new battery in the DMM.

Are ya sure ?

It's actually happened Twice in the last 5 years with a 9v batt.

I keep a New batt. in all 3 of my DMM's and check them frequently .

~

 

[HKJ]

Are ya sure ?

It's actually happened Twice in the last 5 years with a 9v batt.

I keep a New batt. in all 3 of my DMM's and check them frequently .

~

If the battery is ok, you need a new DMM.
Many cheap DMM wil show a wrong value when the battery voltage is low, the better meters will show a "low battery" warning before that happens.

 

[TooManyGizmos]

~

One of my meters is a Fluke .

Actually ... any time I get an unexplainable reading like that ......

I immediately stop what I'm doing , and install a tested new battery .

To this day , I can't explain it - or understand it .

Has anyone else ever experienced a dead 9v reading 12v. ?

~

 

[mdocod]

This is totally normal and expected IMO for the type of test you performed, there is no such thing as 2 perfectly matched cells, and when the juice runs out the voltage plummets at an insane pace in lithium chemistry cells. So the difference between 2.66V and 0V is likely representative of only a few percent variation from cell to cell.

Using an LED to create a scenario of a continuous low drain that one single battery in the circuit could support through the resistance of reverse charging the other cell also supports that the numbers you came up with are entirely accurate.

FYI: Purposely creating scenarios that reverse charged CR123s was the method that several CPFers used here years ago to re-produce real-world causes of CR123 explosions.

Eric

 

[Ecolang]

I have a totally unused white "Panasonic" cell that now registers a negative voltage. It is about -0.15V. these are the cells that say "Matsushita Elestric" in the small print on them.

It was bought 4-5 years ago and like all the others it appears to have died. Just got a light that has a maximum voltage of 6V so dug out my unused CR123 cells to see how it'd perform. It didn't so I got out the voltmeter. The cell has now been dumped for recycling so can't check the voltage again.

 

[Chrontius]

Those are the cells that came with my Maxfire LX. I hope I didn't keep them around for feeding to single-cell vampires...

 

[rookiedaddy]

FYI: Purposely creating scenarios that reverse charged CR123s was the method that several CPFers used here years ago to re-produce real-world causes of CR123 explosions.

Hi Eric, thanks for the information. :thumbsup: Is this the link to the experiments that you refer to?

Another question to all, is there still enough juice left in the cell(s) to do any damage? If the cell did reverse charge to much lower negative Voltage, will it ? With such dimly lit LED, I guess there weren't much current that can be draw from these cells, so with such low current draw, will it still cause any damage poof?

 

[Black Rose]

Yes, that would be the link of the tests.

I hope you have that light somewhere where it can't do any damage to anyone or anything.

I think you are very lucky that thing didn't turn into a cannon.

 

[TooManyGizmos]

Another question to all, is there still enough juice left in the cell(s) to do any damage? If the cell did reverse charge to much lower negative Voltage, will it ? With such dimly lit LED, I guess there weren't much current that can be draw from these cells, so with such low current draw, will it still cause any damage poof?

~

At the point of failure and rapid dis-assembly - it's not a matter of how much juice is left in it .

It undergoes a chemical change inside which goes into what is called "thermal runaway" and that's when it can "rapidly vent with flames" like a little rocket engine , and rapidly expelling hot expanding gasses which are un-healthy to breath . The chemical reaction fire is very difficult to extinguish . Or it could simply just blow-up all at once , with little warning.

If this happens while the cell is in a sealed flashlight , the expanding gasses cause the light body to rupture and explode , with differing results . It could be deadly .

Even with a reverse charged cell just sitting loose on a table , it may be possible for it to go into thermal runaway and cause a serious fire .

Trying to/or mistakenly charging a "Primary" Li Ion cell can cause it to vent and explode ! Don't try it .

We are not sure at what point exactly , they turn into terrorist cells , and self detonate .

~
And don't buy "NukeFire" brand cells made in "Chernobyl" or "ThreeMileIsland" .
~