7 ms·

Why a Dead Alkaline Battery Bounces [video]

289 points by Walkman 12y ago

dang 12y ago
Url changed from http://lifehacker.com/test-if-your-batteries-are-dead-by-dropping-them-on-a-h-1630525062 http://lifehacker.com/test-if-your-batteries-are-dead-by-dro..., which points to this.
- tzs 12y ago
  Due to a Feedly bug (I think), this actually makes it much harder for Feedly users to comment. When an HN story links directly to YouTube, Feedly omits the link to the comments that is normally present in its display of HN RSS. I think this is a Feedly problem, not an HN RSS problem, because it works fine in Digg Reader. I'm curious if others have noticed this. I believe when someone posted a poll question here asking what RSS readers people switched to after Google Reader went away, Feedly was one of the most popular.
- abcd_f 12y ago
  Aha! It is very unusual to see a youtube link not just on the front page, but at the top spot of it.
- raldi 12y ago
  I'm not saying this was the wrong move, but one drawback of the change is that I'm not in a setting where I can watch a video with sound right now, so the writeup is much more helpful than the video to me. On the other hand, as long as you make a comment like this when you change a link, it alleviates the problem pretty well.
lowglow 12y ago
Electrons change things, yo™ :)
- tbingmann 12y ago
  It has electrolytes!
  - peterclary 12y ago
    It's what plants crave.
- lowglow 12y ago
  Meh, I don't care if I lose more stupid fucking Hacker News points, but I can't understand why I would have been down voted for this comment.
keeperofdakeys 12y ago
Probably not the best idea to open a battery without gloves and a mask (though lithium batteries are worse in terms of gases). Still very interesting to see the electrolyte though.
- jacquesm 12y ago
  The quantity and variety of things that I've opened up during my lifetime without 'gloves and a mask' would probably scare you very much. The worst mistake I made to date is grinding off the top of a BLY90 as a kid before I knew what a MSDS is. So far so good, I think these folks will be fine as long as they wash their hands afterwards before eating, cleaning up after you've dropped a fluorescent tube is probably a lot more dangerous than this. Don't go and turn anything into a fine powder! Probably the most risky thing they did here was cutting up the batteries with a hacksaw which will create a bit of sawdust composed of metal and some electrolyte. But that's pretty easy to get rid of and won't become airborne. Using a grinder for the same job would be much more dangerous.
  - akavel 12y ago
    As to what people would play with without "gloves and a mask": http://en.wikipedia.org/wiki/Demon_core http://en.wikipedia.org/wiki/Demon_core "After Slotin's accident, hands-on criticality experiments were stopped, and remote-control machines were designed by Schreiber, one of the survivors, to perform such experiments with all personnel at a quarter mile distance." Note: "After"... so what was the situation before?...
    - cjslep 12y ago
      They would raise and lower the top half of the core with their bare hands, a screwdriver, and lots of shims. Literally hands-on criticality experiments.
  - dredmorbius 12y ago
    BLY90: an RF power transistor. MSDS: material safety data sheet. Just what is it that's inside the BLY90 that's so bad?
macromaniac 12y ago
It's interesting to me that using the height of the bounce against the ground for estimating the spring constant is worse than using the height of the bounce against the battery.
- jacquesm 12y ago
  I don't really agree with that part of the test setup. The mass and springiness of the battery versus the slug dropped mask the fact that this is a double spring setup, there is also still the bottom of the battery contacting the base it all sits on so you can expect some of the bounce to be transferred to the battery which would not jump a whole lot. So at a minimum there would have to be a hard connection (clamped or glued in place or something like that) between the base and the battery to compensate for that.
haar 12y ago
I think one of the bits I liked most was "Romeo (Retired Old Men Eating Out) Club" - looking at its website it seems like quite a large thing over there. I know that my Grandma goes to something similar (restricted to just tea and bingo), but it makes me wonder if a similar organisation exists in the UK; a lot of the older folk I know just aren't very social any more, simply due to the fact that their social groups have died off or are spread out and have restricted travel options. Social interaction seems such a huge part of our existence to be missing for any individual (unless that's what they want of course). Again, anecdotally; I've found amongst the older folks that those engaged in discussion and interaction keep their wits about them longer/easier than those bound by isolation. Anyway, enough babbling on - time to go do some research.
- mhandley 12y ago
  One excellent organization is U3A http://www.u3a.org.uk/ http://www.u3a.org.uk/ My father runs one of their groups that specializes in studying geology, and they regularly have a hundred people turn up to the seminars they run. Science and social go well together when you've lots of free time.
  - warbastard 12y ago
    My father also runs one of these to help people learn Photoshop (mainly for editing family photos). It's surprising the topics that can be learned though these groups
- namtuots 12y ago
  http://www.menssheds.org.uk/ http://www.menssheds.org.uk/
- ixtli 12y ago
  My grandmother runs a (quite large) group that provides a similar type of community for retired women over 65. It's a really interesting idea: they're all very smart and do a lot of interesting stuff. Most memorably they gave speeches in the Connecticut state senate advocating the right to euthanasia for terminally ill people of sound mind.
JosephRedfern 12y ago
The method has even been patented! http://www.google.co.uk/patents/US5567541 http://www.google.co.uk/patents/US5567541
- mdda 12y ago
  The patent was drafted very generally, but seems to focus on the volume (rather than elasticity) of the internal components. OTOH, it would be great if it were even more generally drafted, since its priority date is in 1995. 1995+17 = 2012, so the world is now wide open for innovation in this area, unimpeded by patents (IANAL).
mixedbit 12y ago
They could go further with the experiment to check if a material of which the battery content is composed matters or if the stiffness of the content is the only important factor. They could for example check how bounciness changes when a battery is filled with a gel-like substance which could then be frozen.
dblacc 12y ago
What would the inside of a recharged battery look like I wonder.
- simias 12y ago
  It's not the same technology and I wouldn't recommend tearing a lithium battery apart to look inside. Actually, I wouldn't recommend tearing apart any kind of batteries, lots of nasty stuff inside. You can find plenty of videos on youtube showing you the process, for instance: https://www.youtube.com/watch?v=BliWUHSOalU https://www.youtube.com/watch?v=BliWUHSOalU
  - junto 12y ago
    After watching that it made me think that lithium batteries could be turned into a weapon on a plane by terrorists. Assuming that they are that easy to accidentally short them out. Should they not be a banned from being taken in the cabin?
    - TazeTSchnitzel 12y ago
      They'd probably ban them if people didn't want to use laptops and phones.
    - iamds 12y ago
      It's probably not banned because someone who could take over a plane with a lithium battery could take over a plane without a lithium battery.
      - leephillips 12y ago
        But someone who could take over a plane with a nail clipper could probably manage without it, too.
        kd0amg 12y ago
        And the TSA allows nail clippers in the cabin.
rtb 12y ago
For some reason, it upsets me that he refers to spent / empty / used batteries as "bad", as if they were faulty.
- jasallen 12y ago
  He managed avoid the "flat" vs. "dead" controversy by making up a new convention altogether.
  - bitJericho 12y ago
    I think "consumed" would be most appropriate.
    - fnordfnordfnord 12y ago
      I'd say "depleted" but we're all missing the point.
- jdpage 12y ago
  "Bad" is what I used growing up. I think it's by analogy to food--you would say that food has "gone bad" after a while. Similarly with batteries. You might also ask "are these batteries (still) any good?" to question not their quality in general, but their state. It's almost certainly a regional thing.
tke248 12y ago
Here is the transcript if you don't like watching the video http://bit.ly/1uD31Uz http://bit.ly/1uD31Uz

289 points by Walkman 12y ago

dang 12y ago

Url changed from http://lifehacker.com/test-if-your-batteries-are-dead-by-dropping-them-on-a-h-1630525062 http://lifehacker.com/test-if-your-batteries-are-dead-by-dro..., which points to this.

tzs 12y ago
Due to a Feedly bug (I think), this actually makes it much harder for Feedly users to comment. When an HN story links directly to YouTube, Feedly omits the link to the comments that is normally present in its display of HN RSS. I think this is a Feedly problem, not an HN RSS problem, because it works fine in Digg Reader. I'm curious if others have noticed this. I believe when someone posted a poll question here asking what RSS readers people switched to after Google Reader went away, Feedly was one of the most popular.
abcd_f 12y ago
Aha! It is very unusual to see a youtube link not just on the front page, but at the top spot of it.
raldi 12y ago
I'm not saying this was the wrong move, but one drawback of the change is that I'm not in a setting where I can watch a video with sound right now, so the writeup is much more helpful than the video to me. On the other hand, as long as you make a comment like this when you change a link, it alleviates the problem pretty well.

lowglow 12y ago

Electrons change things, yo™ :)

tbingmann 12y ago
It has electrolytes!
- peterclary 12y ago
  It's what plants crave.
lowglow 12y ago
Meh, I don't care if I lose more stupid fucking Hacker News points, but I can't understand why I would have been down voted for this comment.

keeperofdakeys 12y ago

Probably not the best idea to open a battery without gloves and a mask (though lithium batteries are worse in terms of gases). Still very interesting to see the electrolyte though.

jacquesm 12y ago
The quantity and variety of things that I've opened up during my lifetime without 'gloves and a mask' would probably scare you very much. The worst mistake I made to date is grinding off the top of a BLY90 as a kid before I knew what a MSDS is. So far so good, I think these folks will be fine as long as they wash their hands afterwards before eating, cleaning up after you've dropped a fluorescent tube is probably a lot more dangerous than this. Don't go and turn anything into a fine powder! Probably the most risky thing they did here was cutting up the batteries with a hacksaw which will create a bit of sawdust composed of metal and some electrolyte. But that's pretty easy to get rid of and won't become airborne. Using a grinder for the same job would be much more dangerous.
- akavel 12y ago
  As to what people would play with without "gloves and a mask": http://en.wikipedia.org/wiki/Demon_core http://en.wikipedia.org/wiki/Demon_core "After Slotin's accident, hands-on criticality experiments were stopped, and remote-control machines were designed by Schreiber, one of the survivors, to perform such experiments with all personnel at a quarter mile distance." Note: "After"... so what was the situation before?...
  - cjslep 12y ago
    They would raise and lower the top half of the core with their bare hands, a screwdriver, and lots of shims. Literally hands-on criticality experiments.
- dredmorbius 12y ago
  BLY90: an RF power transistor. MSDS: material safety data sheet. Just what is it that's inside the BLY90 that's so bad?

macromaniac 12y ago

It's interesting to me that using the height of the bounce against the ground for estimating the spring constant is worse than using the height of the bounce against the battery.

jacquesm 12y ago
I don't really agree with that part of the test setup. The mass and springiness of the battery versus the slug dropped mask the fact that this is a double spring setup, there is also still the bottom of the battery contacting the base it all sits on so you can expect some of the bounce to be transferred to the battery which would not jump a whole lot. So at a minimum there would have to be a hard connection (clamped or glued in place or something like that) between the base and the battery to compensate for that.

haar 12y ago

I think one of the bits I liked most was "Romeo (Retired Old Men Eating Out) Club" - looking at its website it seems like quite a large thing over there. I know that my Grandma goes to something similar (restricted to just tea and bingo), but it makes me wonder if a similar organisation exists in the UK; a lot of the older folk I know just aren't very social any more, simply due to the fact that their social groups have died off or are spread out and have restricted travel options. Social interaction seems such a huge part of our existence to be missing for any individual (unless that's what they want of course). Again, anecdotally; I've found amongst the older folks that those engaged in discussion and interaction keep their wits about them longer/easier than those bound by isolation. Anyway, enough babbling on - time to go do some research.

mhandley 12y ago
One excellent organization is U3A http://www.u3a.org.uk/ http://www.u3a.org.uk/ My father runs one of their groups that specializes in studying geology, and they regularly have a hundred people turn up to the seminars they run. Science and social go well together when you've lots of free time.
- warbastard 12y ago
  My father also runs one of these to help people learn Photoshop (mainly for editing family photos). It's surprising the topics that can be learned though these groups
namtuots 12y ago
http://www.menssheds.org.uk/ http://www.menssheds.org.uk/
ixtli 12y ago
My grandmother runs a (quite large) group that provides a similar type of community for retired women over 65. It's a really interesting idea: they're all very smart and do a lot of interesting stuff. Most memorably they gave speeches in the Connecticut state senate advocating the right to euthanasia for terminally ill people of sound mind.

JosephRedfern 12y ago

The method has even been patented! http://www.google.co.uk/patents/US5567541 http://www.google.co.uk/patents/US5567541

mdda 12y ago
The patent was drafted very generally, but seems to focus on the volume (rather than elasticity) of the internal components. OTOH, it would be great if it were even more generally drafted, since its priority date is in 1995. 1995+17 = 2012, so the world is now wide open for innovation in this area, unimpeded by patents (IANAL).

mixedbit 12y ago

They could go further with the experiment to check if a material of which the battery content is composed matters or if the stiffness of the content is the only important factor. They could for example check how bounciness changes when a battery is filled with a gel-like substance which could then be frozen.

dblacc 12y ago

What would the inside of a recharged battery look like I wonder.

simias 12y ago
It's not the same technology and I wouldn't recommend tearing a lithium battery apart to look inside. Actually, I wouldn't recommend tearing apart any kind of batteries, lots of nasty stuff inside. You can find plenty of videos on youtube showing you the process, for instance: https://www.youtube.com/watch?v=BliWUHSOalU https://www.youtube.com/watch?v=BliWUHSOalU
- junto 12y ago
  After watching that it made me think that lithium batteries could be turned into a weapon on a plane by terrorists. Assuming that they are that easy to accidentally short them out. Should they not be a banned from being taken in the cabin?
  - TazeTSchnitzel 12y ago
    They'd probably ban them if people didn't want to use laptops and phones.
  - iamds 12y ago
    It's probably not banned because someone who could take over a plane with a lithium battery could take over a plane without a lithium battery.
    - leephillips 12y ago
      But someone who could take over a plane with a nail clipper could probably manage without it, too.
      - kd0amg 12y ago
        And the TSA allows nail clippers in the cabin.

rtb 12y ago

For some reason, it upsets me that he refers to spent / empty / used batteries as "bad", as if they were faulty.

jasallen 12y ago
He managed avoid the "flat" vs. "dead" controversy by making up a new convention altogether.
- bitJericho 12y ago
  I think "consumed" would be most appropriate.
  - fnordfnordfnord 12y ago
    I'd say "depleted" but we're all missing the point.
jdpage 12y ago
"Bad" is what I used growing up. I think it's by analogy to food--you would say that food has "gone bad" after a while. Similarly with batteries. You might also ask "are these batteries (still) any good?" to question not their quality in general, but their state. It's almost certainly a regional thing.

tke248 12y ago

Here is the transcript if you don't like watching the video http://bit.ly/1uD31Uz http://bit.ly/1uD31Uz