How to tell a dead battery from a good one

[MBAustin]

A friend posted this on Facebook this morning:

VIDEO: I Never Knew This Simple Test To See If Your Battery Is Dead. This Is Genius! | American Overlook

Just tried it out on my drawer of dead batteries waiting to go to recycling, along with a new battery. It works! Super simple!

 

[Bestwifeever]

Some funny comments there.

Try it with eggs too to see if they are still fresh.

 

[REWahoo]

Try it with eggs too to see if they are still fresh.

And be sure to post the video...

 

[M Paquette]

I wonder if this test works for a car battery?

Volunteers?

 

[braumeister]

I wonder if this test works for a car battery?

Volunteers?

How about a Tesla S?
Although they don't seem to be very bounceable ...

 

[easysurfer]

A friend posted this on Facebook this morning:

VIDEO: I Never Knew This Simple Test To See If Your Battery Is Dead. This Is Genius! | American Overlook

Just tried it out on my drawer of dead batteries waiting to go to recycling, along with a new battery. It works! Super simple!

Very cool.

Unfortunately, seems to only work with alkalines and not NiMH.

 

[NW-Bound]

This may work also with living things. I remember hearing the phrase "Dead cat bounce" in the past, though it has to do with stock trading.

 

[MRG]

I wonder if this test works for a car battery?

Volunteers?

As a kid I ran auto parts for a year. Auto batteries definitely bounce as they crack and break. Not good.

The ones that bounce the best were the early('78) GM Freedom batteries. First sealed batteries, expensive as all get out. The box didn't have a bottom on it. When you used a battery clamp and swung them into a pickups bed they frequently fell out. Luckily I never got charged for breakage, as I managed to do it several times.

 

[tfudtuckerpucker]

Thanks to some engineers at Princeton, we can see the results of the "bounce test". It's interesting, but it only tells you if there is 50% charge or more.

 

[timo2]

Thanks to some engineers at Princeton, we can see the results of the "bounce test". It's interesting, but it only tells you if there is 50% charge or more.

I like the disclaimer "Just because it bounces doesn't mean it's dead"

 

[robnplunder]

I just use my tongue to lick one end while the other end held by my wet finger. If there is a tingling sensation, the battery is alive and so am I. If not, ....

 

[LoneAspen]

So does this mean electricity has mass?

If so, that's very interesting, as I'd never heard that before.

 

[marko]

This may work also with living things. I remember hearing the phrase "Dead cat bounce" in the past, though it has to do with stock trading.

No. This is the "Dead Bat Bounce". Different.

 

[donheff]

I just use my tongue to lick one end while the other end held by my wet finger. If there is a tingling sensation, the battery is alive and so am I. If not, ....

The tongue test works with 9V batteries but 1.5?

 

[Bestwifeever]

No. This is the "Dead Bat Bounce". Different.

Maybe during the dead bat bounce the batteries sometimes make little tiny "whee" noises that only W2R, the oracle of e-r.org, can hear before her proclamations.

 

[ERD50]

Here's a link to the Princeton article:

Princeton University - Battery bounce test often bounces off target

The video in the OP is garbage. Sample size of one, different brands, no control over the height and release of the drop or the observation of the bounce.

Note the Princeton article uses identical batteries, probably from the same lot, and controls everything, and measures along a continuum of charge levels to test for sensitivity. Science.

Bottom line, one would probably be hard pressed to tell anything other than the battery is maybe at > 60% of charge level. The bounces below 60% ar all about the same.

-ERD50

 

[6miths]

Yes I tried this last night with a bunch of batteries I had in the drawer and a sleeve of new Costco batteries. All AAs. And my voltmeter. Didn't work all that well and was consistent with the Princeton study (thanks for that). Works for truly dead most of the time as they really bounce. Also may have been my drop technique but I had quite a few good batteries fall over.

 

[Texas Proud]

I just finished trying it..... I would say that it is a good check if there is nothing else there to help...


My 'bad' batteries tested as low as 0... yep, no charge at all.... up to 1.27....

SOOOO, I have a question... what volts indicate a bad battery The video seems to be at around 1.2.....

 

[aja8888]

I have a test for battery condition with #2032 nickel size flat 3 volt batteries. I put one in my garage door opener and if the garage door does not go up, the battery is dead.

 

[aja8888]

SOOOO, I have a question... what volts indicate a bad battery The video seems to be at around 1.2.....

I guess it would depend on the load circuitry. In my garage door opener, its under 2 volts that render it useless for that purpose.

With a flashlight, the light just goes dim to the point where it won't be adequate, but you would have to measure the remaining voltage of the battery.

 

[ls99]

Read the Princeton article, now I know that zinc oxide is part of golf balls for bounce.

As is true in all research, more research is needed. Does repeated bouncing dissipates the charge of a fully charged battery. What happens if a discharged battery is bounced 100 times. How about at 50% discharged battery, does it gain or lose charge?

I am too lazy to do the experiments.

 

[ERD50]

...

SOOOO, I have a question... what volts indicate a bad battery The video seems to be at around 1.2.....

It depends on the application.

Some applications are very low current drain, and can work down to low voltages. Some are very low drain, but drop out at not-so-low voltages.

Some are high drain, and can work down to low voltages. Some are high drain, but drop out at not-so-low voltages.

So you could actually move batteries from more demanding applications to less demanding ones to get more life out of them.

In things like clocks, I think it is mainly the shelf life of the battery - the actual drain seems minuscule.

But if you find a voltage-life chart for the battery chemistry in question, they typically have a pretty sharp drop off at a certain voltage - here's some good charts, with various current drains:

Discharge tests of Alkaline AA batteries

-ERD50

 

[robnplunder]

The tongue test works with 9V batteries but 1.5?

It should work with car batteries for sure but I strongly recommend people don't try it at home.

 

[NW-Bound]

I just finished trying it..... I would say that it is a good check if there is nothing else there to help...

My 'bad' batteries tested as low as 0... yep, no charge at all.... up to 1.27....

SOOOO, I have a question... what volts indicate a bad battery The video seems to be at around 1.2.....

+1 on what ERD50 said.

I would like to add that when a battery gets depleted, not only that its voltage drops but its internal resistance also increases.

So, you may measure a battery voltage at 1.4V with a voltmeter, but if you put a load on it, a bad one may drop big time. A flashlight will have a big draw of several hundred milliamps, hence causes a larger voltage drop (bulb is dim), while the same battery may work a while longer in a portable radio, which may draw only in the tens of milliamps (unless you turn it on really loud).

 

[ERD50]

...

I would like to add that when a battery gets depleted, not only that its voltage drops but its internal resistance also increases.

So, you may measure a battery voltage at 1.4V with a voltmeter, but if you put a load on it, a bad one may drop big time. ....

Yes, it's good to point out that in those curves, they measure the battery voltage while it was under that load. If you remove the load after it dropped to say, 1.2 V, the voltage will typically recover quite a bit. Probably pretty close to 1.4 volts open circuit. But it would soon drop to the 1.2V after re-applying the load.

Although, this 'bounce test' is actually a crude [-]measure[/-] indicator (it's too non-linear and flat to call it a 'measure') of the depletion of the chemicals themselves, so it is a rough indicator of a low remaining charge level.

-ERD50