Systm Episode 20 - Batteries: The Organic iPod/LiO Fire Battery Failures

[jcduerr]

in my opinion not a very good show, best part was the bloopers.. just my opinion though

[kdepasquale]

I actually had the video freeze a little after 16 min in. Froze in both Quicktime and iTunes, and VLC gives me a "seeking too far" error. Was it just my download, or is the video file messed up towards the end?

[scienceking]

You can't test the max current a battery can handle in a load in the way attempted in the show, by just shorting out the battery through an ammeter. What happens is that electrochemical cells generate a mainly constant potential between the anode and the cathode. This is what they supply: Voltage only. No electrochemical cell supplies a nominal current.

So you must then test it with different loads to see the max current it can supply without "wearing out" the chemistry in the electrolyte. Mind you, the electrolyte acts like a transportation system transporting free electrons. If you try to pull too much current, the transportation system will crash, and you will get no practical potential between the electrodes anymore. This is why batteries "die", but get better again if you let them rest.(the electrolyte is able to reach a usable equilibrium again)

So you do load testing to determine what the battery can handle. In the real world, this is actually very complicated and takes a power engineer a while to figure out what his PSU can handle under different conditions. There is a piece of test equipment called an electronic load that is used for this purpose.

The poor man's way is to just use resistors of decreasing resistance(or a decade box) until you notice a significant potential drop across the electrodes starting to take place. It should resemble an "S" curve if you remember from chemistry. back up to the asymptote of the curve and record the current you get there. That is a good 90% I[max] spec for your battery. This isn't totally perfect, as electrochemical cells in practice are not just constant voltage sources, and also have stuff going on like internal resistance. I don't think I have ever had to care about this once in my [short] tenure as an engineer. But I'm sure it comes up.

Of course, its even better to just always try to keep the power your designs use as low as possible anyway, and you can usually avoid all of this that way for hobby purposes. But "the boss" at an engineering firm won't settle for anything less than proof that your system will never overload its power source, with good reason.

Also note that shoring things out over an ammeter is never a good idea. An ammeter does act mostly like a short circuit, and if you short out the wrong thing(like a car battery), it might burn up or something if it doen't have a proper fuse. You might get a current reading out of some batteries this way, but thats because you are measuring the current caused by the battery potential over the internal resistance of the battery. In theory if our battery really was an ideal voltage source, you'd get a current of V/R=V/0=>inf....which is never good. ^_^;

Now, if you really wanted to power the iPod off lemon power, what you could do is get one of those nifty new super capacitors and charge it with the lemons. Then you ought to have a bit more luck. Hopefully the lemons can give it enough juice to keep it topped off.

Otherwise it was a good show. Nice overview of LiIon tech. Too bad you didn't get the battery to combust though! Although with the mega billion dollar recall losses and lawsuits, I'm pretty sure the engineers at the companies who make those spend a great deal of time and effort these days tweaking them not to. Maybe if you tried an older one... :D

[tempesta]

I hope we can all keep our heads together about the cursing .....

[cbudden]

Why was the swearing bleeped out. It's not like there are kids watching this.

Son of a *****

[lindqvist]

Am I alone to notice a trend of declining quality of the Systm episodes?

My personal favorites are the old episodes, but I think that Dave and Patrick have some real potential, but this kind of episode just seems badly prepared and well, the word half-assed comes to mind.

[scienceking]

I think that Dave and Patrick have some real potential, but this kind of episode just seems badly prepared and well, the word half-assed comes to mind.

I think the trick is to think about it in perspective. In the past, Systm episodes came out very spaced out in time, but were pretty darn good when they came out. Now, they have a new one every week. So, we will have good episodes about as frequently as in the past, like the MAME one in the works. But between these good ones, we will literally have ones that were just thrown together to wait out the storm. This is because Systm does not have a production team nearly large enough to produce the old style show weekly...I think they maybe should move to a less ambitious schedule unless they can prove otherwise.<_<

Still, if Patrick and Dave can give us a top notch episode once in a blue moon, they'd be at least on par to the old Systm. My only suggestion would be to maybe try to do multipart but simple projects during some of these episodes. Some great examples of stuff that works for this might be a DIY audio amp like for boosting music from your iPod. It will consist of a few parts, and you could spend an episode on each part. This is actually the typical Analog Electronics I type engineering class lab for teaching designing modular analog stuff, but Systm could just do it for building from a premade design and skip the design stuff.

[fyrefiend]

You can't test the max current a battery can handle in a load in the way attempted in the show, by just shorting out the battery through an ammeter.

I'm glad to see I'm not the only one to notice that.

[lindqvist]

I think the trick is to think about it in perspective. In the past, Systm episodes came out very spaced out in time, but were pretty darn good when they came out. Now, they have a new one every week. So, we will have good episodes about as frequently as in the past, like the MAME one in the works. But between these good ones, we will literally have ones that were just thrown together to wait out the storm. This is because Systm does not have a production team nearly large enough to produce the old style show weekly...I think they maybe should move to a less ambitious schedule unless they can prove otherwise.<_<

Still, if Patrick and Dave can give us a top notch episode once in a blue moon, they'd be at least on par to the old Systm. My only suggestion would be to maybe try to do multipart but simple projects during some of these episodes. Some great examples of stuff that works for this might be a DIY audio amp like for boosting music from your iPod. It will consist of a few parts, and you could spend an episode on each part. This is actually the typical Analog Electronics I type engineering class lab for teaching designing modular analog stuff, but Systm could just do it for building from a premade design and skip the design stuff.

I guess what it comes down to is how low you want to go to keep to the schedule...
My personal opinion is that they should throw the schedule out the window for now and take some more time making the episodes.



This episode felt pretty pointless to me.

For instance, we got to see them rack up a nice array of lemon batteries and then do absolutely nothing with them other than hooking up a volt meter and then a misguided attempt at metering the current.


Hey guys! Just do something to prove the point, that you made a battery that can actually do something "useful"!
At least light up a LED, there _must_ be plenty enough juice (no pun intended) for that!
Or maybe you could even have gotten some small device, like one of those little Digg counters from an earlier episode to run off it?

That would actually have made it seem more worthwhile and "real"...

Just an example of something that could have been done better...

[vincent12234]

I thought the show was good, I'll give you guys the benefit because you do it every week, might try suggesting once every two weeks, to have some bigger projects or something around their, all in all I liked this one.

[optimus]

Why was the swearing bleeped out. It's not like there are kids watching this.

Son of a *****

I'm 12!

j/k. Good ep, learnding is the ****!

[wizmaster]

I thought the show was good, I'll give you guys the benefit because you do it every week, might try suggesting once every two weeks, to have some bigger projects or something around their, all in all I liked this one.

I'm for bi-weekly. I say have the big projects spaced out with mini multi episode projects in between. The MAME project would have to be multi. As a matter of fact, they could have a MAME segment after each episode. I think the weekly schedule is straining the content too much and the lack of actual projects is disturbing. I don't mean to be mean to newbies, but there's always GOOGLE and Wikipedia for them. Heck, links in the "shownotes"/official thread is a better way. Projects all the way with small segments on types of tools, basic stuff, etc. Nice and all but not a substitute to acually building something.

[dom]

Another boring lecture from Systm.

Can we please get back to having some real projects? Or at least lectures about things you actually know about.

Thanks.

[dusanmal]

Suggestion to Systm producers: do show us Patrick testing the car battery amperage in the same way as he have tested lemon and potato batteries amperage. I suspect it'll be fun :)

Everything best,

Dusan

[fwgmills]

You can't test the max current a battery can handle in a load in the way attempted in the show, by just shorting out the battery through an ammeter.

<snip>

Also note that shoring things out over an ammeter is never a good idea. An ammeter does act mostly like a short circuit, and if you short out the wrong thing(like a car battery), it might burn up or something if it doen't have a proper fuse. You might get a current reading out of some batteries this way, but thats because you are measuring the current caused by the battery potential over the internal resistance of the battery. In theory if our battery really was an ideal voltage source, you'd get a current of V/R=V/0=>inf....which is never good. ^_^;

To measure amperage put the multimeter in series with your circuit. If you try to measure directly (as you did) with a large voltage you'll either burn the electrical bridge inside the meter, or you'll blow the meter up...or both. So wear your gloves and face shields before you do that.

[jibberish]

Sorry for the pun, but I think the segment with the lemons, was it's self a lemon. I mean I think that everything they showed in that lemon segment should have been in the bloopers, not in the actual episode.

Come on guys, WTH was the point of showing you didn't know what you were doing? We (not me included, but the proverbial "we") are already good enough at not knowing what to do, or what this stuff is. That is why we watch Systm, so that someone can learn us these magical thing-a-ma-jigs.

If you want to make a show about something, don't do it half-ass. Research your stuff, and present it in a complete and concise manner. Yeah, have fun doing it like you guys do, but maybe leave the bulk of that for the gag-reel?

If you don't understand something about what you are going to do a show about, (Like the whole lemon thing... :rolleyes: ) why not ask someone else; how about your forum members? We seem to know a lot about this stuff! :) I am sure that some concerned citizen on these forums (hint, hint, me...)could have written you a 1000 word or more essay explaining everything to do with the lemon battery from building it, explaining it's operational characteristics, how to test it, to proof of concept. It is always a good idea to have a bunch a intelligent people to bounce ideas off of for a show, and I think that maybe this forum could be that for you.

Patrick you are a know-it-all, and don't get me wrong we love you for it. However when a know-it-all fails at knowing something when they try to explain it, it tends to be a crash and burn. Here, you crashed and burned. Please change the way in which you are making these episodes so that this does not happen anymore. If that means pushing back the production schedule, then do it. If it means outsourcing the research to your forum, then do it. Just don't not do anything.

Systm should be viewed as the replacement for Mr.Wizard, don't continue to disgrace Mr.Wizard!

[tempesta]

I enjoyed this, but i did notice the lack of any real project being done. However, I am aware that for all the great shows you guys do, there going to be one where you sort of just touch on a subject. I have no problem with this. Soldier on, mighty Systm!

[pinfu]

Or at least lectures about things you actually know about.

What? That description of a lithium ion battery was amazing... And how about explaining that a rechargeable battery is rechargeable.

[toadx]

Sorry. This show was really bad. Please try harder next time.

[klipschfan]

There was a report on talk radio and apparently on CBS News as well that a cancer researcher in Erie Pa. discovered that sea water would burn if exposed to a certain radio frequency.

Patrick had asked for a better way to rip hydrogen from a water molecule.

I know I'm late to this discussion but I switched this subscription from iTunes to Google Reader and simply forgot to add the shows to my playlist. I'm caught up now. Sorry Roger and Robert, I put Patrick ahead of you in line.