Testing the 9V Battery Hack (or: Assault on Battery)
Kipkay over at Metacafe has posted videos showing how you can take apart a 9V battery and use the cells as AAAA or AAA batteries (he has a similar trick for 12V -> 1.5V button batteries. I have played with batteries a lot in my life and never knew this. There was some speculation on reddit that it was a hoax of some kind, so as a good sciencer (like a scientist, but we don’t get the lab coats) who really didn’t want to get started on the morning chores, I decided to try it myself with a new 9V I had sitting around. I learned a couple useful things.
Duracell batteries are harder to open than the video implies. My dainty needle-nose pliers weren’t enough — I had to go find larger clampy ones. The edges of the case are also sharp. This would be very tricky to do in a car somewhere without tools.
He tells us these are AAAA cells, which makes sense. You know, I didn’t even know AAAA cells existed until I encountered a tablet stylus that used them. The handy thing is that they can double for AAA batteries in most cases — they just won’t last as long.
I decided to test them in my TI-86. One important thing he doesn’t mention is that there’s no reliable way to tell the polarity once you’ve disconnected them, so mark them somehow as you take them apart. If you’re just guessing, you’ve got 16 combinations to work through.
I didn’t think about this, so I cut them apart and folded over the remaining half-tabs on each end, then tested them all with a multimeter to get the polarity (my digital multimeter is missing, so I couldn’t get exact volt-readings).
I put them in the calculator. It didn’t turn on. I added a bit of aluminum foil at the contacts to make sure they were all touching.
It works!
So, in conclusion: This is a decent way to get AAA batteries in a pinch for a bit less than what they cost in the store, although I don’t use 9Vs for much, so situations where this is helpful are gonna be a bit rare. AAAs in a pack of 8 usually go for about $0.70 a battery, 9Vs for around $2 — so $0.33 per AAA. AAAA batteries are rare enough, and marked up enough, that if you have something that uses them this could be a worthwhile main source.
August 20th, 2007 at 2:23 pm
Cool! Thanks for testing it. I love your comic, by the way.
August 20th, 2007 at 2:26 pm
Great! Thanks for the random fact :p
August 20th, 2007 at 2:27 pm
Awesome! I love disassembly-based science.
August 20th, 2007 at 2:29 pm
Right, except that the typical 9V battery has a max of ~400 mah, while a typical AAA battery is up to 1000 mah. So, these will last less then half the amount of time as typical AAA batteries.
August 20th, 2007 at 2:36 pm
I learned of this a few years ago when I replaced the main circuit board in an old Angel LCD paintball marker with one from a Generation-E Matrix. The old Angel board was powered by a NiMH battery which fit in one of the marker’s tubes, whereas the Matrix board was powered by a regular 9v battery. I learned that if I took the casing off the 9v I could unfold the cells and fit it all in the Angel’s tube.
Also, I discovered something interesting. Different battery manufacturers connect the cells in different ways. As pictured, the cells in Duracell 9vs are connected by flat pieces of metal that are soldered to the cells. In Energizer 9vs the cells are separate, and press up against small boards with traces in the top and bottom of the battery. This was less convenient for my paintball purposes, but would probably be better if you wanted to use the individual cells as AAAA or AAA batteries.
August 20th, 2007 at 2:42 pm
Very cool.
Rumor has it you’re in the Cambridge area. If you ever wanna do team trivia with some people from fark.com, We go to John Harvard’s monday at 9pm.
This isn’t commentspam, I swear. Us farkers love your comics.
You should have my email from this comment.
August 20th, 2007 at 2:49 pm
Note: The title of this page says “Blog Archive”. Seeing that this is actually a blag, you may want to fix that.
August 20th, 2007 at 2:50 pm
I have that calculator. I thought those things went into the ether after I got past my first 3 semesters of college, because I never heard anything about them again.
EVAR.
Nor did I have any need to use mine.
Awesome info though!
August 20th, 2007 at 3:01 pm
Note: the silver on the calculator is foil plating from chewing-gum wrappers. If you’re careful, you can peel the foil up from the wax paper and use it to faux-silver-plate things pretty impressively. That’s what remains from a plating I did one day in high school, six or eight years ago, so it’s pretty durable.
August 20th, 2007 at 3:08 pm
Want a bet if this hack catches on that the battery companies will quickly change the current design?
August 20th, 2007 at 3:25 pm
Hack’s don’t catch on enough, most people are never willing to go far enough to bother. I’m more concerned stripped cells more likely to leak.
August 20th, 2007 at 3:26 pm
“Right, except that the typical 9V battery has a max of ~400 mah, while a typical AAA battery is up to 1000 mah. So, these will last less then half the amount of time as typical AAA batteries.”
These are AAAA not AAA, they are just close. You’re also trying to compare 400mAh at 9V and a AAA is 1000mAh at 1.5V. mAh are the rated milliamp hours that battery is rated for, not a statement of energy stored.
You need to take (mAh * V) = Wh (multiply by 3600 for Joules)
Watt hours are how you compare different batteries unless they’re at the same voltage.
August 20th, 2007 at 3:38 pm
I opened up lots of 9V batteries as a kid and found that they’re not all constructed this way - some contain a stack of 6 rectangular shaped cells, kind of like a pez dispenser.
August 20th, 2007 at 3:45 pm
Did you get cancer when you opened up a battery and started playing around with it? Radiation poisoning? Something?
August 20th, 2007 at 3:53 pm
If the whole battery is 400mAh at 9V, and the cells are each 1.5v connected in series, then each cell is 400mAh at 1.5V.
In terms of energy per dollar, it’s actually a loss at the prices you stated above for AAA batteries, as you’re paying more than 40% of the price for 40% of the total energy.
With regard to opening 9V batteries:
I’m not sure what brand does this, but I’ve seen a couple that don’t have individual cylindrical (AAAA) cells inside. These have a plastic casing inside the metal shell with the electrodes and electrolyte paste layered to make six cells in series. These batteries wouldn’t be very useful for salvaging AAAAs.
August 20th, 2007 at 4:14 pm
Interesting stuff. I remember taking apart a 9V in the 1980s and finding it was a vertical stack of six lozenge-shaped cells, rather than six long cylinders side-by-side. This is (IMHO) a change for the better….
August 20th, 2007 at 4:25 pm
The correct term is “scientician” ;)
August 20th, 2007 at 4:36 pm
I hate to tell you, but I think your calculator is having floating point issues calculating e^pi - pi. Everyone knows that should come out to 20.
August 20th, 2007 at 4:37 pm
God of reverse engineering :)
August 20th, 2007 at 4:57 pm
I thought they were called “scienticians”, not “sciencers”. :-)
August 20th, 2007 at 5:05 pm
http://www.labwear.com - oh come now, there’s just no excuse good enough for not having a lab coat - I mean, they even have free embroidery!!
August 20th, 2007 at 5:23 pm
I took apart a 9V long ago and was surprised to see it was AAAA’s in there. It’s also kind of icky in there so…. just buy your AAA’s from the store. Or steal ‘em from your relatives’ remote when you visit or something.
I also have that calculator, but mine’s OVERCLOCKED. Um, yes it does graph a bit faster than yours does. It’s not worth it though, it takes some brutality to get it apart - it’s not really meant to come apart, and you’ll have little nicks on the edges afterward.
August 20th, 2007 at 5:39 pm
You’re forgetting one minor detail in your cost calculations. The cost of a product includes the labor to produce it. Somehow I doubt people will start ripping apart 9V batteries just because it’s 40 cents cheaper than a fully packaged product. I also doubt that the performance characteristics and safety profile of your makeshift batteries are the same.
I’m just sayin’. Carry on, Sciencer~
August 20th, 2007 at 5:54 pm
From the pictures it looks like there are crimps in one end of each cell. Couldn’t you use that to tell the polarity?
August 20th, 2007 at 6:11 pm
Now THAT I LIKE! - never took one of those apart. 6 x 1.5 = 9
Way back when, there were huge batteries called A and B (often used to power ‘portable’ radios in the vacuum tube days) so they had high voltage output to power the tubes (and short life) They were also made by connecting large numbers of smaller cells together, and wrapping them in a (cuboidal cardboard) box, with a couple connectors on the outside. Dad had a Bendix (formerly i aviation electronics), and I have an old Zenith ‘transoceanic’ (which was a workhorse in the army in WWII) which used these batteries. Fortunately, both also could be plugg in (to the wall there are a couple sources for duplicating these old batteries by using scads of AAs.
Never heard of AAAA. Now, as things so often go, I should run across something that uses them shortly.
August 20th, 2007 at 6:39 pm
You suck. TI is for grade school. Real men use HP calculators with reverse Polish notation (which I guess is kinda like the Reverse Cowgirl for Engineering classes).
My bro took apart a 9v battery when we were younger and it was made out of AAAA batteries just like that. So when it hit the intarblarg, I just shrugged my shoulders and wondered why it took people so long to figure this out.
I also tend to think that devices don’t use 9v batteries anymore, with low-dropout voltage regulators and less-than-5v Vcc voltages and DC-DC converters and stuff, so I’m betting that optimizing the output of a 9v battery with lozenge cells or whatnot isn’t worth it anymore.
August 20th, 2007 at 7:49 pm
I would have thought that a fairly reliably way of working out polarity would be to use a meter, after all doesn’t everyone have at least a basic multimeter in their toolbox? Or failing that, a marker pen during disassembly?
August 20th, 2007 at 9:06 pm
John: Er, those are exactly the two things I mentioned. I used the meter to determine polarity because I forgot to mark them as I disassembled.
JeffBell: I created those crimps when I cut the flat metal strips connecting them.
August 20th, 2007 at 11:05 pm
It’s fairly easy to tell the polarity on cylindrical cells like these.
The negative end (anode) is almost always part of the cylindrical case, and is generally flat with no large bumps. The negative end is pretty clear on the top center cell in the second picture.
The positive end (cathode) is generally a cap or button connected a rod leading into the interior of the battery, and is isolated from the casing by a plastic insulator. The positive end looks like the top left or right cells in the second picture (the black plastic insulator is also visible around the button contact).
You can also see a single crimp in the metal casing circling the cells on the positive end of the cells (the metal casing is connected to the negative contact, and the crimp is around the plastic insulator insulating the positive contact).
August 21st, 2007 at 1:15 am
Awesome, thanks for the info, I’ll be sure to remember this when I need some cheap AAA batteries.
By the way, your comic rocks.
Keep it up man.
August 21st, 2007 at 5:44 am
I thought about the crimps as a means of polarity indicator, as well. In any case, wouldn’t it be easiest to solder a small, flat metallic cylinder to the + pole? That way, you’d have almost retail AAAA batteries ;)
About RPN, TI and HP: I have heard rumors of a mod that enables TI users to use that. Using google, I couldn’t find satisfactory results. Does anyone know more about this? Is it a hoax?
August 21st, 2007 at 5:53 am
whow, really cool hack!
August 21st, 2007 at 6:02 am
This works only with the ‘alkaline’ kind of 9V batteries, others are, as commented above, stacked. Dunno how it is over on the other side of the pond, but over here in Holland IKEA sells those AA and AAA batteries for ridiculously cheap (as in E0.075-0.15/apiece). Seeing that you put AAA’s in devices that use no to almost no current (remotes, wall clocks, etc), it might be wise to get those el-cheapo ones instead of the expensive Duracells.
August 21st, 2007 at 7:13 am
For this cost calculation:
If you really have to use batteries, like for calculators or sth., it would be the cheapest to use rechargeable batteries aka accumulators. I don’t know about the energy prices in the US (I guess they are low compared to Europe) but I’m pretty sure, it’s worth it.
However, I know, it is kind of difficult to get them, I was searching quite a while for them in the US and Canada, but I know they are outthere… I wonder why it is sooo hard…
Not to mention the eco aspect…
August 21st, 2007 at 8:23 am
[...] just for quirky science-ing observations and an all-round good read, as demonstrated by this Assault On Battery [...]
August 21st, 2007 at 9:05 am
[...] manier om aan goedkopere batterijen te [...]
August 21st, 2007 at 9:18 am
ift, you’re wrong. Ampers and Ampers hour are dependant of voltage, so 400 mAh at 9V is not 400 mAh at 1.5v, that’s why Bill Batteryman tells you to convert the units to Watts/Hour (using Voltage) which is the correct way to compare the batteries.
August 21st, 2007 at 9:41 am
But can you do the opposite, and hack together a faux 9v battery using the AAA betteries that everyone has lying around all the tme anyway?
August 21st, 2007 at 4:15 pm
@toshiro and A Half-Polish Programmer:
There’s an application for the TI-83 to do basic calculations available at the following link. Personally, I’ve never been impressed with TI’s interfaces… And I think my HP48SX is kinder on the batteries, too! ;c) I think I understood RPN calculators by the age of 10, before I ever laid my hands on any calculator that assumed algebraic inputs.
http://www.ticalc.org/archives/files/fileinfo/233/23378.html
August 21st, 2007 at 5:06 pm
@ A Half-Polish Programmer:
I love the HP 15C. Am glad to know that there are other reverse-polish devotees keeping it real out there.
August 21st, 2007 at 5:43 pm
Lars:
Actually, he is right. 400 mAh at 9V is not 400 mAh at 1.5V, but it *is* equivalent to 400 mAh at 1.5V *six times*, which is what you get out of one 400mAh 9V battery.
August 21st, 2007 at 5:57 pm
you can also use the top and bottom pieces to make a battery snap. pretty useful if you build things that use 9 volts.
see:
http://www.instructables.com/id/EOGAE2LXOUEP287E6N/?comments=all
August 21st, 2007 at 8:41 pm
And here I thought I was going to be clever and be the first to criticize for not using an HP. In case you RPN junkies weren’t aware, HP finally released the true successor to the 32SII a couple of months ago, the 35S. Check it out. Big ENTER keys are back in style, baby.
August 22nd, 2007 at 4:46 am
Mathematica >> HP
August 22nd, 2007 at 1:17 pm
[...] has a cool article up about how you can get some cheap AAAA or AAA batteries from a 9v in a pinch. Here it is if you are interested. And yes, I know it wasn’t his idea initially, but I think he runs [...]
August 22nd, 2007 at 1:35 pm
Matthew: I think that you could do the reverse in theory, but the problem is that these are AAAA sized batteries so they wouldn’t fit in the place that holds the 9v battery unless there is a lot of wiggle-room for some reason. In a pinch though… I’d guess probably. You’d probably need a cheap battery casing or some soldering skills to get them to stay connected though.
Also, I think a lot of people are missing the point of this hack. 99% of the time, there is not reason you will ever want to use this to get AAA batteries, but it is a tool to remember if you need to be “heroic”: “Stand Back I’m Going to Try Science”
August 22nd, 2007 at 1:37 pm
The Hell…
“The Blog with No Title » Blog Archive » Lori’s back! Says:
August 22nd, 2007 at 1:17 pm
[…] has a cool article up about how you can get some cheap AAAA or AAA batteries from a 9v in a pinch. Here it is if you are interested. And yes, I know it wasn’t his idea initially, but I think he runs […]”
That’s my blog, but I have *no* idea why it posted it on here. Does Wordpress do that automatically if you link to an article on another site? Odd. Spam unintentional I promise! :)
August 22nd, 2007 at 1:57 pm
And you think Duracell’s AAA division will let you get away with this?! Expect vengeance, with gory results.
August 22nd, 2007 at 2:10 pm
Hm, If Brandon’s blag submits stuff without him doing anything, it’s obviously figured out the spam protection. Time for new spam protection?
August 22nd, 2007 at 4:47 pm
Here’s my question: was the calculator betrayed at some point by some white out? Because the back of the ol’ 86 seems awfully not black, which isn’t normal.
August 22nd, 2007 at 10:15 pm
Jeremy: HP finally made the true successor to the 32SII, and not that abomination called the 33s? Sweeet!
August 22nd, 2007 at 11:32 pm
Sex.
August 23rd, 2007 at 6:10 am
I found this link, it reminds me about the comic of the wet riffs; airguitar in the shower porn:
http://www.aboutcolonblank.com/?p=520
moanmyip.com : sexy girls moan your ip; total geek humor ;-)
August 23rd, 2007 at 6:40 am
The lozenge vs AAAAs is pretty much a matter of spec vs. implementation. The spec requires it to be of particular dimensions and voltage but the implementation is up to the manufacturer.
Stacks are probably easier if you aren’t also making AAAAs. AAAAs are probably easier if you’re already making them (even if they aren’t finished quite the same).
Stacks is what one will normally see on pictures in books on science aimed at young kids (when we learn that the 9v things are correctly “batteries” and the 1.5v things are correctly “cells” and we remember the distinction for about 5 minutes before we go back to calling both “batteries” like everyone else, unless our inner nerd insists upon a moment of pedantry), but maybe that’s just the matter of what was the norm at one time.
August 23rd, 2007 at 9:51 pm
I wonder what it would look like if I opened a 9V I have lying around that I ran 12V of current from an AC adapter through overnight. The battery is bulging, nearly cylindrical.
August 24th, 2007 at 4:01 am
Please, think about the nature! Buy rechargable batteries! (well, i’m french. Is it the right word? batteries you can uh… fill again with power? repowerable?)
August 24th, 2007 at 7:02 am
Xuelynom: Yes, rechargeable, right word.
twopeak: Someone’s already registered http://www.wetriffs.com and is accepting submissions..!
Andrew.
August 24th, 2007 at 7:18 am
Lars: The 6 cells are in series, so if you’re drawing 400mA from the battery, it’s equivalent to drawing 400mA from each cell. Therefore, each cell will also be rated at 400mAh, but at 1.5V. So, actually, you’re wrong.
August 24th, 2007 at 8:47 am
See, you should have had me for a physics teacher in HS. I cut up a 9V years ago and I drag it out to show my classes every year. Same with a big ol’ cylindrical capacitor!
I really enjoy your comic, by the way. Thank you.
August 24th, 2007 at 11:41 am
Watch horny women do live cam show, free chat
August 24th, 2007 at 6:39 pm
Sure, you can get batteries cheaper at the IKEA… But what’re you gonna to do when the raptors take over the local IKEA?
Hunh?
You know what you’re gonna do?
Hide in a corner while we disassemble our nine volt batteries to power our calculators so we can plan a counter-attack!
August 25th, 2007 at 9:40 am
What is that foil on the calculator? It wouldn’t happen to be the foil from gum wrappers, would it? I did that to my calculator a few years ago, and now I can’t for the life of me remember why I would do such a thing, or where I got the idea.
August 25th, 2007 at 1:29 pm
I think the part where one blog posts to another blog is called a “trackback” or “ping”, “pingback” or something like that. I see it a lot. I’m surprised that it hasn’t been used to death by spammers in an attempt to get more traffic or a better pagerank. Maybe it turns out that it doesn’t do anything for pagerank.
August 25th, 2007 at 1:35 pm
I forgot to mention that my dad had been given a few promotional penlights that used AAAA batteries. This trick may be a good way to get cheap A^4 batteries because they are so stinking hard to find and expensive.
Yes, rechargeables should be favored, but I haven’t seen any rechargeable A^4 batteries, and the only rechargeable 9V batteries I’ve seen was over a decade ago and were only NiCd, not the newer NiMh or rechargeable alkalines. Which is better to use depends on the use. IR remote controls that last over a year on batteries are probably far better off with just plain alkalines. High-current devices should be rechargeable.
August 26th, 2007 at 9:05 pm
In regards to the white on the calculator, it does look like it submitted to white-out at some point, as did my own CASIO scientific at one point. The size of the screen and the overwhelming number of buttons was causing me to freak out at important moments, such as in the middle of physics exams. To solve this problem, I took the liberty of writing on the back, in large friendly letters, the words ‘Don’t Panic’. It thus scores slightly higher over my sister’s Texas instrument, which doesn’t have these words and if I remember correctly, was slightly more more expensive than mine :D
Apologies to Douglas Adams for the extensive ad-libbing.
August 27th, 2007 at 2:58 am
And hey—I see that you too are a fan of the excellent TI-86, with its unobtrusive menus, efficient complex number notation, and complete lack of advanced graphing and CAS features! Hail and well met! ^_^
August 28th, 2007 at 12:36 pm
Congratulations, You are in the top 100 undiscovered websites by pcmag!
(No kidding, check by yourself: http://www.pcmag.com/article2/0,1895,2174685,00.asp)
cheers
August 28th, 2007 at 12:39 pm
BTW, if you are looking where exactly, you will basically have to click 7 times on “next”
August 29th, 2007 at 12:41 am
so I tried this because my brother’s ti-89 ran out of batteries. I was pulling the half tabs off because they had torn, and the battery casing literally shot out of my hand, nearly into my eye. the sound of it was so loud my ear hurts.
August 29th, 2007 at 4:13 pm
Vicki: I did exactly the same thing. (Seventh grade math class, though. At the time, I was utterly astounded by the number of buttons.)
August 30th, 2007 at 5:08 am
It’s “may you live in interesting times” dude! an altogether different proposition.
August 30th, 2007 at 12:42 pm
I knew AAAAs existed but has anybody ever seen a single A battery?
August 30th, 2007 at 2:05 pm
So, I don’t know if you noticed, and I didn’t read through all 75 comments, but the batteries are actually easily visibly identifiable, the one side has a physical ring indentation, in my experience, that’s the positive side.
August 31st, 2007 at 8:09 am
Off topic, but congratulations on getting your short accepted into Machine of Death. I look forward to reading it.
August 31st, 2007 at 1:28 pm
Hey, I think I
August 31st, 2007 at 1:30 pm
…the rest of that was supposed to say <3 you.
August 31st, 2007 at 6:45 pm
http://en.wikipedia.org/wiki/A_battery_%28vacuum_tubes%29
single A batteries
September 2nd, 2007 at 3:31 am
“These are AAAA not AAA, they are just close. You’re also trying to compare 400mAh at 9V and a AAA is 1000mAh at 1.5V. mAh are the rated milliamp hours that battery is rated for, not a statement of energy stored.
You need to take (mAh * V) = Wh (multiply by 3600 for Joules)
Watt hours are how you compare different batteries unless they’re at the same voltage.”
But the whole point of this is to show you that 9v batteries are close enough to six AAA batteries that they can be substituted for them. So that means that the each 1.5v cell has (shock) ~400mAh - coompared to ~1000mAh for buying the AAA batteries in the first place. Also the AAA batteries actually fit in properly. This hack is only really useful if you can’t find any AAAA.
September 2nd, 2007 at 12:12 pm
Excellent calculator! I am a big fan of my trusty TI-86.
September 5th, 2007 at 5:03 pm
Well it looks like your battery hack screwed up your calculator’s floating point handlers. e^[pi] - [pi] should be 20.
September 7th, 2007 at 8:42 am
@JeffDM:
Actually, if you look at Harbor Freight Tools, they have a line of NiMH 9V, I think rated for 700mAH.
September 16th, 2007 at 11:43 pm
It seems like it would be more useful to do this in reverse. Take 6 AA batteries and turn them into a 9 volt battery that would last longer. Interesting experiment either way, though, thanks
September 18th, 2007 at 7:01 pm
Max Kuipers seems to be the only one to look at the screen of the calculator. I’m dissapointed with all of you. 83 posts and only one mention of the actual comic.
September 20th, 2007 at 12:54 am
Battery hack update: bunches of AA size batteries inside a 6v lantern battery! However, they seem to be low-charge cells, and some 6v are made from larger 1.5v cells inside.
September 20th, 2007 at 6:11 am
[...] is in mijn kinderjaren) dat een 4.5V batterij bestond uit 3 AA batterijen. Maar niet dat een 9V batterij bestaat uit 6 AAAA batterijen (of dat AAAA bestond), en nog minder dat een 6V (bestond) uit 32 AA’s bestaat! Hetzelfde voor batterijen die je [...]
September 21st, 2007 at 11:23 pm
Love the ti-86. Best calculator the school ever bought for us.
September 24th, 2007 at 2:53 am
Pffft… TI-86. TI-89 FTW! :D
September 30th, 2007 at 4:49 am
I have the same calculator! but mine is the silver edition! jealous much?
I liked this little fact, but i’m wary of opening up batteries as ive seen the massive stain on my uncles desk where he tried to open up some kind of battery and it leaked battery acid everywhere. this is the same uncle who once took apart a nappy (diaper to you) to see how it worked…
September 30th, 2007 at 12:26 pm
asdfzsdg
September 30th, 2007 at 12:27 pm
kjhn;iouhn
September 30th, 2007 at 12:28 pm
September 30th, 2007 at 12:27 pm
September 30th, 2007 at 12:29 pm
seen the massive stain on my uncles desk where he tried to open up some kind of battery and it leaked battery acid everywhere. this is the same uncle who once took apart a nappy (diaper to you) to see how it worked…
September 30th, 2007 at 12:29 pm
fkmdjhn njm2q23wedzdsfSARf
October 1st, 2007 at 6:28 am
[...] Testing the 9V Battery Hack (or: Assault on Battery) [...]
October 17th, 2007 at 5:30 pm
I have a TI-86 and some 9-volts. This looks like a fun project just for the hell of it.
November 21st, 2007 at 11:54 pm
For real fun, find an old Polaroid SX-70 film pack battery. These were wrapped in lots of black darkroom paper, but they had warnings every few folds: DANGER DO NOT OPEN THIS BATTERY PACK, WARNING CORROSIVE SUBSTANCE INSIDE and so on. They must have had a dozen warnings, and a yard or two of wrapping. Needless to say, we kept going until we hit the metal plates and corrosive substance which wasn’t all that nasty. Maybe Polaroid was afraid someone was going to eat it.
SX-70 batteries were hot stuff when they came out. The reusable flash was serious and the film shot out of that camera lickety split. I’m not sure what kind of battery it was, but it was more powerful than anything on the shelf at the drugstore.
November 22nd, 2007 at 6:25 am
Cool. But if I really needed power for my TI 86 and only had a 9V battery, the same thing could surely be accomplished without opening the battery, using a resistor in the loop?
December 1st, 2007 at 4:31 pm
I did the exact same thing to my (now retired) Ti-83 in HS! I wonder how many other people have done that to their calculators…
December 11th, 2007 at 12:17 am
“One important thing he doesn’t mention is that there’s no reliable way to tell the polarity once you’ve disconnected them, so mark them somehow as you take them apart. If you’re just guessing, you’ve got 16 combinations to work through.”
That is a bit off don’t you think? Did you not notice that only one end of these batteries has a bevel where the other end does not? That would be a good start in distinguishing between each ends polarity after taking them apart. That is providing the specific battery you are working with has these same distinguishable features but it is likely they do.
Also 16 combinations? Where did you pull that number from? There are 6 batteries each with 2 ends that would total 12 but that is even over kill since each of these batteries are the same you eliminate 5 leaving one battery with 2 ends. Only one of which is positive and one is negative so it should not be overly difficult to interpret which end is what now should it?
Cool experiment though, to bad it has already been done yet you do have some good pics of it.
December 12th, 2007 at 6:33 pm
4 batteries in the calculator, 2 ends : 2^4 = 16. Do you /really/ want to go math pedant here?
Deep love for the TI-86. Got mine from a yard sale for $3 out of a $1 remote-control bin. He wanted to charge me three because it was ‘So fancy’, so I let him.
Also a plug for TiCalc.org(above).
December 19th, 2007 at 1:13 am
Ted…
Are you sure this is correct?…
December 19th, 2007 at 5:23 am
Additionally there is an easy way to discern the positive versus negative ends of a battery.
Are you ready for this?
…are you?
A diode. For the sake of simplicity a LED (and a 1K resistor…you know, so you don’t blow out the LED). Since current can only travel in one direction through a diode (through a process leading sciencers have determined to be magic) the light will only turn on when you have the battery connected correctly. (And it has a low enough power requirement that you can test individual batteries thus eliminating the exponential combination problem.
December 30th, 2007 at 12:52 am
HAHA. I love the test screen. e^x-x
19.9990999792
*siren goes off*
ROUNDING ERROR!! EVERYONE EVACUATE!!
January 12th, 2008 at 11:03 am
You renew my hope to find an IC packed with tiny vacuum tubes.
January 17th, 2008 at 2:49 pm
I tried it and it exploded in my hand
February 19th, 2008 at 6:49 am
Nifty. Forwarding this to a preparedness site I frequent.
March 24th, 2008 at 6:51 am
Hey, thanks for this. A few people come into my store asking for AAAA batteries. Now I have an answer for them!
April 23rd, 2008 at 5:41 am
I had great fun trying to rip apart a 9v Energiser ™ branded battery. But following some cut fingers, I managed to mangle the case open and get to the cells inside. Interestingly, its quite easy to tell the poles apart because the +ve end has a small bump.
April 26th, 2008 at 12:23 am
I still can’t get it to work… I tell you though, I nearly split my finger open on the battery case. Not for the clumsy I’d say. Interesting idea, thanks.
April 28th, 2008 at 7:54 am
Great stuff! It worked, eventually. Hey derek, you’re right not for the clumsy
what exactly was the problem? maybe we can help?
Gord
May 5th, 2008 at 1:47 pm
Yeah, a hoax indeed
http://www.snopes.com/photos/humor/batteryhack.asp
May 8th, 2008 at 7:13 pm
Randall, your dainty needlenose are fine for this. Pry a corner of the Duracell’s seam with a knife and then use the pliers like a sardine tin key. I just did it to retrieve the 9v button-snaps for a project. Like most things, it’s about finding the archimedes spot.
May 14th, 2008 at 9:40 am
Great! Thanks for your trying. You took away a lot of questions!