I’m typing very awkwardly now because the ring finger on my left hand is swollen with a blackened nail and feels like a baby hippo is gnawing on it with those big, flat hippo molars. It’s throbbing. It hurts. It’s like this because in the messy, brutal process of attempting to remove the old, swollen, failed batteries from my Changli. I crushed the tip of that finger between a mass of three fused-together batteries and a steel bar. It hurt so badly I think I became fluent in Dutch for a moment and maybe ejected a searing hot burst of agony-urine. But it was all worth it, because I eventually was successful in getting the old, trapped batteries out of the little EV, but the process was less like car repair and more like demolition. Ugly, loud, messy, crude. But, you know me, that’s how I roll! Oy.
In case you can’t wait or don’t feel like reading, here’s a little video showing the desperate goings-on:
The Problem
You may recall from my last update about the fantastic Changli, the cheapest new electric car you can buy in the whole wet world, that the five lead-acid batteries that the car was supplied with have failed, and, possibly as a result of overcharging or perhaps freezing temperatures, have all expanded and bloated to such a degree that they have effectively wedged themselves into the Changli’s battery box, firmly pressed against the steel walls of the box, immobile and defiant.
After some vain attempts to get the batteries to budge, I soon realized that these batteries were not going to be willing participants, and I needed to just forget the years of service they gave me, propelling that little Changli all over the place, even doing their best in the potent crucible of the racetrack:
For these five lead-acid batteries, though, those days were over, and I now needed to view the heavy lumps of lead as adversaries. I took a good hard look at them and made some plans. The first step, of course, is naming your enemy, and the particular circumstances of these batteries helped me do just that:
Three of the batteries had expanded to the point where they’d fused themselves into one monolithic block: collectively, I named them for the famous First Triumvirate of ancient Rome, Gaius Julius Caesar, Gnaeus Pompeius Magnus and Marcus Licinius Crassus. The other two batteries were not fused to the Triumvirate, but were still swollen and trapped; I named these two for anti-Caesarian members of the Senate, Cato and the famous stabbing-betrayer Brutus.
These names should give a clue to the necessary approach to getting these batteries removed from the Changli’s battery box, the Senate of the car (or SPQR), if you will. To make it happen, I need to destroy Julius Caesar.
Now, in my last post, I got a lot of great suggestions about how to remove the batteries. People suggested the use of straps and hoists, cutting away the steel of the battery box, or perhaps drilling a hole in the bottom and using a floor jack. While these methods may have worked, I decided that I really wanted to avoid cutting the metalwork of the Changli itself.
The batteries are done and useless now. They’re expendable. So, if anything is going to get damaged or destroyed, it should be them, not the Changli, which I want as intact as possible for when I replace the batteries and drive this fine 1.1 horsepower beast again.
The Solution
That’s where the chainsaw comes in. Here, I’ll link the video again so you don’t even need to scroll back up:
The truth is, this turned into a job that was not like car repair; it became a demolition job, just wanton and crude destruction, because the only way anything would move in that battery box was if I was able to actually make available space for motion, and to do that I had to destroy the physical form of at least one of the batteries. And the best choice was Caesar, right there in the middle, locking everything in.
I didn’t have a Sawzall or anything like that handy, so the chainsaw it was. I just needed to break the integrity of the battery – physical integrity, as I’m sure morally this battery collapsed long ago – and the chainsaw did a decent job tearing through the plastic housing and churning up the internal plates and dried-up chemicals, which resembled a lot of potting soil, into a powder that could be re-distributed around the battery box, creating space for me to maneuver the other batteries free.
Have you ever chainsawed through a lead-acid battery? It feels very strange. The consistency of the battery material is dense and soil-like, punctuated with the kick of plastic panels or metal webbing. Smells funny, too. Funny in the equivalent-to-huffing-a-plastic-bag-of-RoundUp kind of way, not the ha-ha kind of way.
After the first round of chainsawing, followed by some careful and precise whaling-upons with a hammer, I was able to break Caesar down enough to the point where I could get Brutus angled enough to be freed from the trap of the outer steel lip of the battery box, and from there I was able to pry-bar it onto its end, and lift it out.
Elated with my small victory, I snorted a fat rail of lead-acid dust, to be sure my mental capacity was impaired enough to continue. It very much was.
From this point on, it was just a fight. An ugly, unpleasant fight with hammers and crowbars, with casualties on both sides. I got Cato out, leaving the three fused-together Triumvirate batteries. An attempt to get them out as one monolith failed, resulting in the smashing of my finger between the batteries and the wall of the battery box, and my finger still fucking hurts.
Livid, I decided that the Triumvirate had dictated the terms of my life for far too long, so I used another prybar and a hammer to separate Pompey from the group, which finally allowed me the room and freedom I needed to drag the demoralized remaining one-and-a-half members of the former Triumvirate out of the battery box, permanently.
There you can see the sorry state of the batteries after I finally got them out. Caesar is half destroyed, but still fused to Crassus. Pompey has some hammer damage, and Brutus and Cato are just horribly bloated and swollen.
I’m also putting a picture of my cat Tomato here, as a way to make up for the gross finger and diseased battery pictures. Tomato watched me the whole time, baffled. That’s healthy.
I’m hoping a battery expert may be able to tell me if the visual condition of the battery internals can give a clue as to how and why these batteries failed; was it overcharging, or damage from freezing, or just age? If I end up going back to lead-acids, how can I avoid the same fate? [Ed note: I’m guessing there was some kind of internal short, maybe a result of high humidity/moisture. -DT].
I’m just happy to have those old batteries out; a tumor has been excised, and I can now start fresh. But what batteries should I put in? I could just get five lead-acid car batteries, but are those going to work as well as the more small electric vehicle-specific lead-acids I had in here before? What is the difference? Can I get batteries with more amp-hours and expect more range? Will regular car batteries tolerate all the charge/discharge cycles or will I need deep-cycle marine batteries or something?
What about a salvaged NiCad pack from a hybrid like a Prius? Or, hell, even a Lithium-Ion pack? But those are crazy expensive, and I’d likely need new charging electronics, too? The point is, I have a lot of research to do, and any input is appreciated. I’ll try and find some experts to consult, and perhaps I’ll start with new lead-acids and then move to something more exotic? I’m not sure yet.
What I am sure of is that I’m excited to get the Changli going again, better than ever, and I never, ever want to have to do this sort of battery extraction job. What a shitshow.
Right as David Tracy was finally veering towards sanity, now we have Torch to keep us up at night.
If Torch keeps huffing lead we are really going to get to experience this bizzarro world where David is a the saner of the two.
Replacing them with LEAF modules would be a fun project. Greentec tells them for $40/ea and has a location in Charlotte, 60V worth would be $320. You can get aftermarket BMSes for them.
Obviously wouldn’t get you more speed, but just think of the superior range and cargo capacity.
You might want to consider batteries designed for a UPS. I’m not sure of the deep cycle capability, but if you actually acquired it with a working UPS and dismantled it, you would have a compatible charger with it too.
UPS batteries are normally just basic sealed lead acid batteries – IE, weaker versions of what he already had.
A while back I scored a larger Eaton unit from a data centre that was definitely NiMH. I opened it up to double check of any obvious electrical faults. It was overkill for me so I passed it on to a friend who had a better use for it. I probably should have kept it and pretended it was my personal power wall, but it was wired for 12V DC racks and converting it appeared to be a hassle.
Go get one of those Harbor Freight lawnmower engines and hook it up to an alternator? Or one of those new rotary engines I’ve been hearing about, the Liquid Piston. Get some old garden hose for the exhaust and use an old milk jug with a hole in the bottom as a gas tank. BAM better than new
Next year: “How I removed my old half full gas tank with a chainsaw”
Man i dont know about using anything from Harbor Freight.
You just watched a man intentionally carve up lead acid batteries with a chainsaw and you’re worried about Harbor Freight? It seems like Harbor Freight would be an improvement to his methodology.
After watching the Vid I have to ask: Is this some kind of Burning Man
event /competition that you participated in?
Yeah, you’re going to want to poke a hole in your fingernail to relieve the pressure the bleeding has caused.
100% will relieve pressure and pain.
He’s got an electric drill. Saw it in the video, lying there waiting to do fingernail repairs.
He’s proabably got an entire civil war field medic’s tool kit. 😉
I would recommend 900 9-Volts in series (or in parallel, I’m not a scientist!) for a very short but very powerful boost.
First, I am glad you didn’t suffer any greater injury – that looked fantastically dangerous, as who knows what you could have been flinging around in the air with that chainsaw. Second, your real problem is that you stopped at the batteries – keep going and get rid of that death trap before it gets you killed.
Bro, that wasn’t what I recommended you do.
Chainsaw to that, Im laughing pretty good. Glad it didn’t kick and eat your face.
With a tip blocker and what looked like the world’s only quadruple skip chain, I’m not sure kickback is even possible for that chainsaw while obeying the laws of physics.
I was kind of marveling at it, because it seems to be specifically designed to not be useful as a chainsaw. Perhaps the salesperson saw Torch and carefully steered him to the tool just for situations like this?
On my first outdoor job (basicslly, weed-cutting vacant suburban lots), I had a co-worker who was just out of prison. He & friends had hit/killed a cow with their truck, and figured they’d harvest some free steak. The only cutting implement available: a chainsaw.
Caught “red-handed”, so to speak . . .
A bloody good time was had by all.
I came here for the stories, but staying for the long term effects of lead poisoning. Never change Torch.
I too was wondering how much lead dust that saw threw up into the air.
lmao. Nice video. Did you get my email about a potential lithium battery sponsor?
I’d say this is going to be your best option if quick and simple is your desire. https://www.homedepot.com/p/12-Volt-50-Ah-Sealed-Lead-Acid-Battery-for-Ryobi-30-in-Riding-Mower-6-EVF-50/319073969 It has slightly less (2Ah)capacity than your existing batteries and seems to be close to the same dimension. Anything of the same type with a larger AH rating will be physically larger.
Of course you’ll still need to check the current charger to make sure it wasn’t the reason that the old batteries fried. To me that or over discharge is the likely cause of the failure. Freezing is far less likely to cause the cases to fuse together than them getting too hot.
Those batteries for Ryobi mowers will be useless for JT in about 2-3 years. While a bit more expensive LiFePo like this is the long term solution: https://www.amazon.com/dp/B0973JM74D/ref=emc_b_5_t?th=1
Getting some good ideas from the readers but they are all just been there done that. How about something different? I seem to remember an episode of Professor Proton where he powered a clock with a potato. Potatoes are cheap, i dont think it has ever been done before. And if they overheat baked potatoes.
Those lawn mower batteries are basically what was in it. While I agree there are a lot of better chemistries available, but then you are asking the person who removed the old batteries with a chain saw to safely do something more than put it back the way it was before the chainsaw got involved…
I figured JT would have no problem taking the chainsaw to the battery box to open it up if space was needed. He already chainsawed and hammered a battery into oblivion, what’s the difficulty in cutting some 14g steel?
I’ll repeat myself, although I don’t know why I’m bothering anymore.
Find out the peak current draw before you decide to change from Lead Acid to LFP. The Battery Management System on most LFPs have a draw limit and if you exceed that, you might damage the batteries. It might be totally fine, but without knowing, you’re just guessing. Or maybe just ignore this sensible advice for whatever reason.
What happened with the Pao Ball Joint?
One last thing about LFPs. If you do go that route, remember that your center of gravity is going to move way up. Although the lower wright might make hill climbs much pacier.
A chainsaw! JFC. Someone please subscribe so the man can buy a damn sawzall or grinder. But maybe if that’s the kind of thing you usually use your chainsaw for, the blade was already too dull to cut your leg off. A chainsaw!!
Jason, you might look into wheelchair or mobility device batteries, which are typically 12V high Ah deep-cycle AGM type. If you have a mobility equipment dealer nearby, you might even get a great deal on lightly-used ones. Insurance and Medicare typically pays to have these refreshed every couple of years, so there are inventories of still-good batteries that can’t be reused in mobility equipment. Not sure where they end up. Hell, I’d give you the four I have sitting around in my garage if you weren’t across the country…
After the first handful of words, I thought you meant wheelchair or mobility device for the impending chainsaw injury.
???? another reason why Jason should know where the nearest mobility device dealer is.
Or get used wheelchairs from Facebook. If they dont work he has the mobility device in the event he cuts his damn leg off.
Yep those were dead Jim.
Yeah price/value it is hard to beat AGM, I have one in my old Honda motorcycle that fired the beast up no problem, it was a new battery in 2014 it’s 2023 last I looked. I do keep it on a maintenance charger for 4 months of the year, keeps it happy in the shed for the cold months.
Before you make any decisions, please do enough homework to know that Prii use NiMH batteries, not NiCad. 😛
Personally, I’d just replace them with another set of decent lead acids (I’m highly dubious that the OEM batteries were in any way “small electric vehicle-specific lead-acids” and not just the cheapest crap Changli could find), but make sure to monitor them to ensure the (presumably) cheapo charger in the car doesn’t ruin them again. Maybe wire voltage monitors to each one like they do in the Prius.
Yes just use regular car batteries and pick up a golf cart charger.
Yep, and NiMH require a very specific charge controller that does very careful load balancing, because those fuckers love to get hot as hell when overcharged.
Then again, lithium batteries are far more sensitive than NiMH to unbalanced loads. Hell, even lead acid batteries work better when properly balanced (see https://www.powersystemsdesign.com/articles/balancing-lead-acid-batteries/95/9383 )!
Basically, any battery matrix should have a proper charge controller to maximize lifespan and minimize risk.
Now adding another Superfund site to the Autopian family
So since you were taking on the Triumivirate, you used the 3 Stooges approach?
Anyway, glad you got them out, got out with only a smashed finger (and hopefully no long term effects from inhaling battery acid dust), and got an article out of it…
As I said on the previous post, avoid NiCad or NiMH for this, it’ll just make your life harder. LFP (aka LiFePO4) is definitely the way to go for a number of reasons.
NiCad (and NiMH) are much more fickle about charging than lead acid or Li+. They also have a much higher self discharge rate, so not only will you lose that store energy faster it not plugged in, but the groups in series will come out of balance much more quickly too. Plus, with 9 of these modules in series, how are you going to charge them? If each module is 7V, then that sounds like it’s 5 cell groups in series, so you’d have a total pack series count of 45. Can you get a 45S charger for that chemistry, or will you need to disconnect them and charge each module separately (assuming you can get a bunch of 5S chargers) each time?
Additionally, NiCad voltage vs SOC curve is not monotonically increasing (it drops from 80% SOC up), and even below that it is nowhere near as linear over most of the range as lead acid or Li+. This will make range and SOC estimation more difficult (you definitely won’t be using stock instruments), and contributes to the charging problems above.
I’d say that the sweet spot is 12v LiFP batteries for their low cost and low likelihood of thermal runaway compared to other Li+, and much greater energy density vs lead acid or NiCad. You’ll still need a smart charger for them, but it’ll be a lot more standard since many ebikes and other equipment use 60v LiFP packs too. The SOC estimates will still be off a bit due to the flatter open circuit voltage vs SOC of LiFP vs lead acid, but it won’t be as wonky as NiCad.
You’ll also need to check the balance manually periodically to make sure that each one is at the same voltage & thus SOC, and discharge ones that are high to keep them all happy. You may be able to find a BMS to handle this automatically too.
Just, please don’t use the charger that came with the changli, and size your cables to account for the current that the new batteries can deliver!
This is the way.
How about a trickle charger to prevent loss after charging?
The loss while storing the batteries is only a part of the problem. A high self-discharge rate means a lot of variability in the self-discharge rate between cells or parallel cell groups, so you’ll get a badly out-of-balance pack much more quickly. A trickle-charger on the whole pack won’t solve the out-of-balance problem, since that current will go through all the cells. Say 20% of the cells out of the series string of ~45 (for NiCad or NiMH) or ~20 (for LFP) are losing charge and thus losing voltage more quickly than the others… For LFP lets say the 20% are at 3.3V (70% SOC) instead of 3.5V (95% SOC) for the other 80% of cells. Therefore, the whole pack reads at 69.2V instead of 70V, and every time you charge the whole pack together, whether with a trickle-charger or any other charger that doesn’t require accessing each battery separately, the charger thinks that the pack is not full, since the total voltage is lower than it expects for a full charge. Therefore, it keeps flowing current through the whole pack in an effort to fill it up, but in the process it overcharges the 80% of healthy cells and never fully charges the 20% that are low, making the whole pack age more quickly. This is true for any type of battery chemistry when there are cells or groups of cells connected in series, but is a much more common problem when the self-discharge rate is high.
Oh my! So many OSHA violations in one story. I know you’re playing it off for laughs, but aerosolizing lead dust with a chainsaw without full PPE seems to be pretty high up on the list. Oh, and next time, get at that nail with a hot nail or similar to release the pressure. Seems scary, but it’s painless and instant pain relief.
Keep JT’s neighborhood weird!
Jason is the boss. Bosses don’t have to listen to OSHA since it’s there to protect employees. Bosses do have to listen to EPA, however. But I ain’t gonna be a downer because small planes be spewing more lead than a torchainskaw.
Wait. You mean the visual condition after you sliced a battery with a chainsaw? I’m not sure their current visual condition tells us much.
All I can say is “Groovy.”
Hail to the king, baby.
Jason’s hometown USA:
“911 operator how may I help you?“
“yeah there’s a small crazed man trying to cut his strange Chinese car in half with a chainsaw. I think he may need some help.”
“ yes ma’am. That’s Jason. We’ve had multiple calls about him. He’s just trying to fix his car. Call us back if there’s some extreme explosion.”
“Uh ok”
Click
DT and JT spend 72 hours together in involuntary commital at the Psyche Ward.
Et tu brute? Then fall off, Jason’s nail.