and just what do we make of this little oddity

[Duncan]

How To Test a AA battery, Easiest Way For Any Battery Fast, Easy! - YouTube
If its true there are implications of course

[ewizard]

That is interesting and useful too! What might also be interesting is to accurately measure the weight of two of the same brand - one dead or low and one good. If they weight the same or very nearly the same then we have something even more interesting although I suppose the makeup of the battery chemistry drained versus new might be different enough to account for the bounce effect. Reminds me of the egg test - hard boiled egg will spin fast but not boiled will slow quickly if you try to spin it. It's whats inside that makes the difference. I'm guessing now that I'm thinking about it that as the battery gets used up it hardens inside which would make it bounce more?

[Peter Lindemann]

Nonsense!

Hey Guys,

This is a joke. One of many like it on YouTube. The Duracell battery has a rounded end that will never allow the battery to stand up like the EverReady will. This has nothing to do with the "state of charge" in the battery.

The chemistry of these battery is such that the total weight of the chemicals in them do not change simply because they have been rearranged and recombined to form other compounds.

As the guy says, "have fun testing your batteries" but don't spend a lot of time on it. The meter works every time.

Peter

[citfta]

Sorry Peter I disagree

I have to disagree with Peter about this. I was very skeptical myself so I decided to try it. I have a lot of AA batteries as most people have for remotes and all the other things that use them. I picked a couple of Duracell batteries from a drawer. I knew there were some that were partially discharged and some that were new. Since they were all Duracells I thought this would be a better test than using two different brands. I did not test to see what the charge state was before I tried the bounce test.

I tried dropping each of them on a formica desk top to see if there was any difference. I dropped them from about 3 inches or so. I dropped each of them about 5 times or so. Very rarely did either battery stay upright after dropping them but the one definitely had more bounce than the other. When I tested them I found the one with the most bounce was showing 1.4 volts and the one with less bounce was showing 1.6 volts. So there must be some kind of change going on that would account for the difference in the bounce ability. Interesting.

Carroll

[Peter Lindemann]

I Like Your Test Better

I have to disagree with Peter about this. I was very skeptical myself so I decided to try it. I have a lot of AA batteries as most people have for remotes and all the other things that use them. I picked a couple of Duracell batteries from a drawer. I knew there were some that were partially discharged and some that were new. Since they were all Duracells I thought this would be a better test than using two different brands. I did not test to see what the charge state was before I tried the bounce test.

I tried dropping each of them on a formica desk top to see if there was any difference. I dropped them from about 3 inches or so. I dropped each of them about 5 times or so. Very rarely did either battery stay upright after dropping them but the one definitely had more bounce than the other. When I tested them I found the one with the most bounce was showing 1.4 volts and the one with less bounce was showing 1.6 volts. So there must be some kind of change going on that would account for the difference in the bounce ability. Interesting.

Carroll

Dear Carroll,

I like your test better, observing the "bounce" characteristic rather than the ability of the battery to stand up. We all know that these types of batteries tend to swell up slightly as they discharge, so the "better bounce" may be indicative of a higher pressure inside the case. Thanks for reporting your test results. I don't mind being wrong if there is something to this. I am just tired of people wasting their time on things that turn out to be goofy tricks.

Thanks, again.

Peter

[ewizard]

I wasn't going to bother testing this as I didn't see it as being that important but ..... since Peter thought it was a joke and cifta made a test I just had to see what is going on with this. My test backs up cifta. Also not sure what sort of Duracell's Peter has but mine stand up just fine as long as you've got the negative end down
Both AA Eveready alkalines as I couldn't find any low or dead Duracell AA's

Battery 1: 0.000 volts as read on Fluke 87 meter
Battery 2: 1.474 volts .... ditto ... Fluke

mixed them up and took them to a room with marble. One battery definitely bounced while the other one just 'went thud' with little or no bounce. Holding the bounced one I went back and measured it as being the 0.000 volt battery. I then weighed both on a small digital scale

Battery 1: 0.000 V weighed 24.3 grams
Battery 2: 1.474 V weighed 25.0 grams

Now I don't think the 0.7 gram difference would make that much difference in the bounce factor. But what I think that tells me is maybe there is a loss of some sort in the bad battery and if that loss increases density of the solids in the chemistry of the bad battery then it will probably 'bounce' better. Alkalines are notorious for leaking and while this one didn't show any obvious signs of leakage I suspect it may have lost a little of some chemical and has just not gotten to the point where it is obvious yet. That's all my 'guess' on this. Since we haven't heard back from Duncan yet I'm not too sure what he had in mind as to the significance of this but after spending this little bit of thought and time with it I haven't figured out yet what might be important here .... other than if I ever find myself without a meter (very unlikely ) than I'll know how to pick the better battery.

[boguslaw]

Woooha! What a nice method.... I hope there is nobody here who can pop up now with a video of ... RECHARGING battery by periodically hitting them on solid ground ? You know... it's old Teslonian method you just have to do it fast and loong time like 3 hours

p.s. joking of course

[liber63]

hi guys,
I believe that the weight difference is very little to account for the instability. More likely seems to me it has to do with some magnetic alignment that takes place which gives the obvious stability of the charged ones. I believe, that was the point Duncan wanted to imply, maybe its very obvious to some of you I am sure and it certainly goes further beyond my knowledge. I know very few things anyway.
Panos

[Duncan]

do you come from a land down under ?

Men At Work - Down Under - YouTube

for you consideration

EEVblog #508 - Can You Test Battery Charge By Dropping It? - YouTube