Russell Graves did teardown of a Craftsman 19.2V DieHard battery and a Ridgid 12V battery:
It’s time for more tool battery teardowns! This week, I’ve got a Craftsman 19.2V DieHard battery, and a cute little Ridgid 12V battery. They’re both lithium, and I’m going to dig into both of them, because that’s what I do with old batteries I pick up out of junk bins.
If you’re bored of tool battery teardowns, you could always send me more interesting things to mess with! I enjoy poking around tool batteries, and a lot of the ones I pull apart are “new to the internet” in that they haven’t had a detailed teardown before. It’s always interesting to see how different companies approach much the same problem.
For the most part I believe things are as they seem. But every once in a while I begin to look at notable technology happenings from a different angle. What if things are not like they seem? This is conspiracy theory territory, and I want to be very clear about this: what follows is completely fictitious and not based on fact. At least, I haven’t tried to base it on facts surrounding the current events. But perhaps you can. What if there’s more to the battery fires in Samsung’s Galaxy Note 7 phones?
I have a plausible theory, won’t you don your tinfoil hat and follow me down this rabbit hole?
Remember Stuxnet? It’s a computer virus that infected and took down the centrifuges Iran was using in its uranium enrichment program. These centrifuges are super-precise; they need to be in order to separate isotopes into depleted uranium and enriched uranium. The process involves software that continually tweaks the balance of the centrifuge — something well explained by Bill Hammack — and disrupting that balance can damage the equipment itself. Many believe that Stuxnet was used in a government-backed attack on Iran’s program to put these centrifuges offline.
Why am I bringing up Stuxnet now? I started to think about the Samsung battery fires and the horrible effect it is having on the world. It certainly has put Samsung in a rough position — perhaps the most respected and trusted maker of Android phones got the battery tech in this phone wrong… twice. How could that be? Perhaps it was corporate espionage. But of course it wasn’t — if anything you’d have to call it corporate sabotage.
How Can You Sabotage a Battery?
Lithium batteries have monitoring circuits built into them. These are responsible for cutting off the cell before it gets too flat (which will damage it), and maintaining acceptable temperatures and constant current profiles during charging. In some cases they can even shunt around cells but this is more of an industrial trick for applications like electric vehicles.
These battery-tending circuits run software, of course. Just last month we saw all the secrets for the controller of a laptop battery unlocked. Smartphones usually have a single cell, but there is still data there — a third conductor that can transfer data like temperature from the battery to the phone.
What if a very carefully crafted virus were able to rewrite the battery charging code of a carefully targeted phone and cause it to fail on purpose? With so many of this particular model in the wild — 1M of the 2.5M manufactured — a virus could be programmed to delete itself 99.99% of the time to avoid detection. The other 0.01% it would go into action — pushing the temperature of the cell past the failing point and thereby destroying the evidence in the fiery process. That would equate to about 100 incidents which is very close to the 112 being reported.
It’s a surprisingly enticing “what-if” and this thought process even opens up my mind to other possible industrial sabotage scenarios. Toyota’s uncontrolled acceleration, for instance. But the simplest answer tends to be the correct one: these are engineering failures. Toyota’s code is a mess, and… well what exactly did happen with Samsung? They have a track record of producing safe phones with energy-dense lithium-ion batteries. I can understand that they got it wrong once… an accident. But how do they get it wrong twice when the stakes are so high?
Discounting the loss in Samsung’s stock value, throwing in the towel on the Note 7 is estimated to be a $9.5 B (yes, Billion) write-off — $5 B of that profit. Which means they could have devoted $2,000 per phone to fix the problem and still broken even. How in the world did they get it wrong the with the recall? Speculation is easy; flying too close to the sun on battery chemistry, a bug in the charging software, a yet-to-be-discovered manufacturing process breakdown, take your pick. The odds are cosmically small that it’s a nefarious battery-torching virus but we’ve come this far so let’s walk through the reasons on why that’s so unlikely.
This is All a Load of Bull
Even if phone batteries have rewritable firmware or the phone’s charging code can be attacked, it would be incredibly hard to get at that functionality from user space on an unmodified OS — then again there were a lot of people sideloading malware-laden versions of Pokemon Go.
Even if someone discovered a way to do this, wouldn’t they be looking for personal gain by selling information on the exploit to Samsung who have the most to gain by fixing it? I feel a recursive conspiracy theory loop coming on so let’s move on.
Motive. There is very little motive for someone to target Samsung. Yes, there is a very public beef between Apple and Samsung over phones that is being heard by the Supreme Court of the United States right now. If you were to make a list of likely sabotage suspects, Apple would be on it. But that line of thinking doesn’t scratch the surface. The only thing to gain here is for Samsung to lose market share, and the risks to a company like Apple are huge. This event could sully the market for battery-powered devices in general, damaging Apple’s own business. And if the plot were discovered the fallout would be devastating.
Some people like to watch the world burn… could it be a lone wolf hacker? Again, very unlikely. This isn’t ransomware or boosting your friends list. These failures can kill and injure — anyone malicious enough to use them would be looking to make a statement rather than flying under the radar.
No, it’s just a promising plot for a sci-fi novel. The irony is that had this recall (minus the conspiracy theory) been in a novel instead of actually going on around us we’d all say it was to far-fetched to be plausible. Keep those mind-control signals out of your head and let us know if you have a favorite tech-related conspiracy theory that’s too good to keep to yourself.