Home » What It’s Like Driving The Cheapest Car In The World After Chain Saw-Ing Out Its Batteries And Letting It Sit For A Year

What It’s Like Driving The Cheapest Car In The World After Chain Saw-Ing Out Its Batteries And Letting It Sit For A Year

Changliback Top2
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It’s sort of appropriate to be telling you about this on Halloween, because this is a story of resurrection from the dead, a Frankenstinian journey of electricity and rebirth. You may recall that my Changli, the cheapest new sorta-car in the known world, suffered a failure last year that was later proven to be due to the death of the five lead-acid batteries that gave the life-force to the Changli — batteries that, in their death throes, swelled up and bloated themselves to such a degree that they trapped themselves in the battery compartment, forcing me to take the sublimely idiotic approach of getting them out with a chainsaw, because I’m stupid, often deeply so. The path to return to motility for the Changli hasn’t been an easy one, plagued mostly by the twin demons of chemistry and procrastination. But, I’m happy to say that in the end, there was victory, and the mighty 1.1 horsepower Changli now rides again!

Part of the reason this process took so long is because – and I tell you this in the strictest confidence – we were supposed to have a battery sponsor for the Changli. We had been talking to a battery maker that dazzled me with promises of lithium-ion power and then just some sort of effective lead-acid power, but the whole process just sort of fizzled out, leaving me and the Changli feeling jilted, alone, and unwanted.

Vidframe Min Top
Vidframe Min Bottom

But there’s only so long you can wallow in self-pity! Lamenting what could have been isn’t getting 800 pounds of Chinese Old Man Happy Car moving again, and, besides, the last thing I want to do is prove all the haters right. Oh, there’s lots of people out there who’d love to see the me and Changli fail! And I’m not going to give them the satisfaction!

Sure, it stung when the American Dental Association (ADA) and the American Council of Learned Societies  (ACLS) issued their first-ever joint press release to condemn my attempts to get the Changli running again, calling the project “a folly that doesn’t just waste time and resources, but fundamentally debases the human spirit,” and referring to me as a “delusional, unpleasant little troglodyte who looks like what a poorly-shaved chimpanzee would resemble if no one was willing to provide it with decent clothing” and then going on to speculate that, should I lose my life in this endeavor, “the cost to the overall worth of humanity would be less than negligible.

Those words hurt. But they also spurred me on.

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[Editor’s Note: Neither the ADA or the ACLS could be reached for comment to confirm the validity of the press release or associated quotes. These may have been made up. – JT]

Let’s recap the state of the Changli: I’d chainsawed out the batteries, reducing my lifespan considerably thanks to lead inhalation, but I got the swollen batteries out. Here’s what that looked like, if you need more horror in your Halloween:

The end result was a nice, clean battery box to work with, though:

Batterybox

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My, that looks fantastic! You could eat off that battery tray, but I sure as hell wouldn’t recommend it! While I’m here, I should inspect the condition of the main battery wiring, just to be safe:

Superbwiring

Just as I thought: it’s in superb condition. No notes! I re-spliced and added some new tape, but looks like I hardly needed to, right? Glad that’s all still top-notch.

So, now I just need to stuff that battery compartment with some electron-filled batteries. I wanted to do this quick and cheap, but I also did not want to get complete garbage. With that in mind, I went to Wal-Mart to see what was available. There were some small lawn equipment batteries that were tempting because they’d all have fit well in the battery box, but I’m not sure those would have had the endurance I wanted.

Really, conventional car batteries aren’t the best choice here, as they’re designed to kick out a burst of power when starting, then spend the rest of the time getting gently recharged by the alternator. I wanted something more suited to continual power delivery. Fortunately, even at a place like Wal-Mart, there’s a reasonable answer for this problem, even in the lower-tech lead-acid battery space: marine batteries.

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Batteriesinpao

The key difference in marine batteries versus car batteries is that marine batteries are designed for more continual power draw because boats will operate lights and pumps and stereos and harpoon gun targeting systems and other equipment directly from the battery in ways that cars just don’t. From Napa Auto Parts:

…their job continues after firing things up. These [Marine] batteries need to provide enough juice to keep the lights running, the gauges functioning and any pumps or other boat accessories fully operational. This means that they must offer a long draw-down on power before emptying out.

Marine batteries have thicker lead plates inside to facilitate this longer power delivery, and should be better about being depleted and recharged over and over. Also, the price wasn’t really any different than the car batteries, so I think we have a winner.

I found five roughly-matching marine batteries at my local store, so I grabbed them all. The marine batteries also had another significant advantage over car batteries: they had better terminals:

Terminals

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In addition to the usual soft-metal post that gets clamped like a regular battery (why are these the standard? They’re pretty crappy. We should look into that in another story) these also had threaded posts that were roughly the right size to fit the Changli’s original terminal wires, as you can see above. They also came with the proper nuts, stored on a plastic positive terminal cover that looked like a face, laughing maniacally:

Terminalface

The one drawback of these marine batteries is that they are significantly larger than the original batteries, so the battery box can only fit three:

3batts

As a result, I had to re-locate the remaining two to the rear floor, behind the battery box:

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All5

There’s still legroom, but these batteries do eat up a good chunk of floor space:

Legroom

Those are my kid Otto’s legs there. It works, but I think I can improve the experience if I make a little battery cover with drink holders or something, to make it all seem intentional and perhaps even add a touch of luxury to the humble Changli.

Battcover

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The batteries need to be wired up in series so the voltages of the batteries add up to the needed 60V; David wasn’t confident that this would all work, predicting the release of Magic Smoke:

Magicsmoke

What a dick, right? Thanks for the confidence, David! Jeez.

Anyway, I wired the batteries up, using wire from an old outdoor extension cord that’s probably too thin and I should change it out, but I really was being impatient.

Wiredup

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Well, joke’s on you, David! It worked! No magic smoke! Sure, Otto told me the wires got a bit hot while we were driving, but the damn thing is alive again! [Ed Note: I do think some thicker-gauge wire would go a long way for you, Torch. -DT].

I’m delighted. I realize this is hardly a heroic fix, it’s just swapping out batteries, but I’m thrilled all the sitting didn’t cause more things to go wrong, and this all just makes me more dazzled by the improbable fundamental non-crappiness of the Changli.

Unwashed

It was still filthy and leaf-covered, so I vacuumed out all the spiderwebs and washed off the accumulated pine needles and squirrel-stashed acorns and leaf litter, and behold, the Changli was looking as smart and together as the finest $1,200 Chinese semi-legal EV you can imagine.

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Washed

Otto and I took the Changli out into town to pick up some food as I evaluated the performance, which felt pretty much the same as I remembered, which makes sense: It’s the same voltage, and even if these batteries have more amps to give, they’ll only give what the motor demands, and since it’s the same motor, it’s about the same.

I did notice the battery charge indicator seems to vary a lot more than it used to. It drops precipitously under load, and then recovers when you’re off the go-pedal. The voltage reading seems right; it was about at 60 when I first tried it, before I recharged any of the batteries, and was around 65V after a full recharge, which is about what it usually was before.

Incity

I think where I may see an improvement is in range. These batteries are just physically bigger, with more materials and chemicals inside to convert to electrons, so I wouldn’t be surprised to see a nice bump in range. The original batteries gave the Changli a maximum tested range of about 27 miles. I need to perform a full range test with the new batteries, but I bet I can hit, oh, 35? I bet that’s possible! Is 40 too much to dream for? I need a whole afternoon to test this out, so I can drive around in a loop until I deplete the battery. Maybe we can do a livestream head-to-head range challenge with David’s $2,000 Nissan Leaf? We’ll keep you updated.

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Juno

The important thing is that the Changli is back, and I couldn’t be happier. Eventually, I’d still like to try to do some real upgrades to this beast, but for now, I’ll start the benchmarking and testing process for these common store-shelf batteries.

The Changli is back, bitches.

Relatedbar

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How I Used A Chainsaw To Remove Batteries From The Cheapest EV In The World

How Wildly Swollen Batteries Have Derailed My Plans To Resurrect The Cheapest Car In The World

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Toobs-N-Stuff
Toobs-N-Stuff
10 months ago

you need to tear out that whole powertrain and drop in a salvaged LEAF motor and battery pack.

Jason Masters
Jason Masters
10 months ago

Jason, you seriously need to up your wire gauge. if the wires are getting warm, they can and will melt the insulation and cause a fire. go get an old (but decent) jumper cable and cut that up and use it if you insist on being cheap. Ive said it before but it bears repeating, your insurance company will deny you if you burn your house down with this wildly unsafe setup.

Marteau
Marteau
10 months ago
Reply to  Jason Masters

Cables are already cooked and coroded, with broken insulation, from the picture.
So fucking stupid

BubbaMT
BubbaMT
10 months ago

The batteries had to cost at least half of original price of the Chagli! Just like a real ev.

V8 Fairmont Longroof
V8 Fairmont Longroof
10 months ago

I don’t believe anyone has mentioned this already, but pleeeeease straighten the bull-bar! My OCD…

Crank Shaft
Crank Shaft
10 months ago

Inside joke for MH, DT, MS, and JT:

An Electric Aside 😀

Hoonicus
Hoonicus
10 months ago

Torch is a nom de plume NOT a modus operandi !!

Paint-Drinking Thundercock Harvey Park
Paint-Drinking Thundercock Harvey Park
10 months ago
Reply to  Hoonicus

Nom de plume… Of smoke?

Cerberus
Cerberus
10 months ago

I’ll be another damn safety nerd telling you to use thicker wires and proper connectors. I know safety isn’t a big seller for you (it’s not so much for me, either, at least if we’re talking electronic nannies), so I will frame the suggestion as also being more efficient. Go bigger even—the little bit you need won’t cost much more in weight or money.

Last edited 10 months ago by Cerberus
Crank Shaft
Crank Shaft
10 months ago
Reply to  Cerberus

You’re not a safety nerd in this case. Torch keeps doing this and does not seem to comprehend the danger so your reaction is entirely appropriate.

Cerberus
Cerberus
10 months ago
Reply to  Crank Shaft

Yeah, I just tried to appeal to something in addition to the safety he so frequently ignores. Usually, it’s the more longterm risk thinking that gets people, like wearing respirators or hearing protection and I’ll admit to having some hearing damage from being “too cool” to wear protection when I was younger and only really appreciating long term lung damage from watching my mother die of lung disease, but Torch doesn’t even appreciate the more immediate risks.

Crank Shaft
Crank Shaft
10 months ago
Reply to  Cerberus

Hearing damage here too. I am a class fool in so many ways. That said, i still speak up when I see anyone getting risky with electricity or inflammables.

Also, 60C is only 140F. What’s the temp in NC lately? Come July, that battery box will get close to that temp without any resistance heating. Ugh.

Bizness Comma Nunya
Bizness Comma Nunya
10 months ago

Honestly I love hearing updates on this thing, and I love hearing stories about vehicles that people think are down/out but somehow keep chugging along. Kinda like an old Top Gear special.

It’s like the Expedition I bought for $1000 for the Gambler, spent no money fixing it, then a fucking TREE fell on it (and my other car, totaled the good one…) drove it to the gambler after the tree smashing, drifted it around a motocross course while hitting every jump at dumb speeds at the event, drove it home without issue. Then I started commuting in it daily for 100 miles, round trip, 3-4 days a week.

Best money I’ve ever spent on a vehicle, no question.

John Crouch
John Crouch
10 months ago

JT, NAPA will make up really great 4Ga battery cables at a really good price. You’re going to melt those wires and burn up that rolling wonton. Next look at golf cart batteries after those Walmart jobs crap out.

OrigamiSensei
OrigamiSensei
10 months ago

Electrical engineer here chiming in with everyone else – thicker wires!

Mike Harrell
Mike Harrell
10 months ago
Reply to  OrigamiSensei

I’m a geologist and even I wouldn’t have used wires that thin for this. If that doesn’t make Jason worry, nothing will.

Penguin Pete
Penguin Pete
10 months ago
Reply to  Mike Harrell

If it’s only a 1kw motor, at 60v there’s less than 17 amps in those wires. It’s probably a bit over spec for salvaged domestic cable, but not by much.

We’re used to seeing massive battery cables as at 12v there can be 60 amps in those cables, and yeah, needs some serious gauge.

Frankencamry
Frankencamry
10 months ago
Reply to  Penguin Pete

It’s not the sustained amperage, it’s the surge/starting. On larger car engines you need another zero in your 12V starting amp number.

I have a few robotics motors. The roughly 3 amp 12v one I found the sheet for first has a starting amp rating of 14. I would be surprised if the ratio was much different for the Changli.

Bracq P
Bracq P
10 months ago

Thumbs up for fixing it and going through with the plan. Am surprised marine batteries don’t collapse under the load (or do you have a large voltage drop under load?) and would have guessed golf cart batteries would be the way to go.

KennyB
KennyB
10 months ago
Reply to  Bracq P

Marine batteries and golf cart are fundamentally the same. The big difference is amperage – with these he has about 75 amps of capacity, with five 12v golf cart batteries he would double that to 150 amps, but also would drastically increase the size of the batteries and the cost. And also a substantial weight increase. 225lbs or so for what he has (group 24 marine deep cycle), 400 for 12v golf cart (group GC12)

The batteries he bought were roughly $500, five 12v golf cart would be $1300 or so. If he were to use 10 6v golf cart batteries the amperage would jump to 200-230 depending on the brand but now you’re at $1500 and 600lbs (group GC2 6v).

With any of these options, you are dealing with wet cell style batteries that you have to maintain the water levels on by occasionally adding distilled water.

His original batteries, judging by the markings on them were 12v 50ish amps absorbed glass mat (AGM) style lead acid. They probably weighed about between 200 and 250 lbs together. Cost to replace them would be $1000 or more.

I’ve lost track of my point…. oh, yeah. Golf cart would add a lot more weight and cost. And take up a lot more space but the marine batteries will do the job just fine after he takes care of the weak point so many other people have mentioned.

Holy shit Jason replace that wiring NOW. Put in some heavy gauge wire to carry the load and be done with it. This is unnecessarily dangerous.

Data
Data
10 months ago

Jason is like the living embodiment of Tim “The Toolman” Taylor, only he didn’t give it more power!

Jack Beckman
Jack Beckman
10 months ago
Reply to  Data

How long he *stays* living if he keeps up these dangerous stunts is the question. And taking Otto in that vehicle with the bad wiring is a bad decision. Please, Torch, fix the wiring!

Marathag
Marathag
10 months ago
Reply to  Data

Closer to Red Green. But where he falls on the scale of Handiness vs Handsome, will leave others to judge

Andrea Petersen
Andrea Petersen
10 months ago

How lame of the potential battery supplier to back out. Look at how much support there is for this! As I type, there’s 54 comments, God knows that’s probably about 100ish potential vehicles to put batteries in. At a few hundred bucks a pop that’s…uhhh, I can’t do math. But money was left on the table through their lack of faith!

Unclewolverine
Unclewolverine
10 months ago

The battery supplier that backed out really missed out on a good deal. Maybe a couple hundred bucks of wholesale product for exposure to dozens of readers. Dozens I tell you!

OFFLINE
OFFLINE
10 months ago

Dude, that thing is going to catch on fire if you don’t upgrade the battery connections. It’s a genuine no kidding safety hazard. Elon’s darkest autopilot fantasies are safer than this. Go get some 0/0 welding cable and crimps and fix this.

MaximillianMeen
MaximillianMeen
10 months ago

The power meter fluctuation is probably due to the inadequate conductivity of the small gauge wiring for the amps you are pulling under load. Higher resistance = bigger voltage drops between load and no load. You need to listen to all the folks telling you to fix the wiring!

Crank Shaft
Crank Shaft
10 months ago

I went to write this very same post. THICKER WIRES NOW!!! It’s a fire hazard!!!

OverlandingSprinter
OverlandingSprinter
10 months ago
Reply to  Crank Shaft

Those appear to be, at best, 10 gauge wires, and let’s say 10 feet of total length. Off the top of my head, that’s maybe 20 amps the wires can take before bad things happen. If the wire is 12 gauge, then, what, 10 amps of capacity?

Anyone know how many amps the Changli motor draws?

OverlandingSprinter
OverlandingSprinter
10 months ago

Replying to myself. I reread the article. The motor is 1 KW. So, 1000 watts divided by 60 volts is ~17 amps, if I’m recalling Ohm’s law correctly. If my guess is correct and the wire is 10 gauge and its capacity is 20 amps in a 10-foot run, then the wire is barely adequate.

It may seem counter-intuitive that 10-gauge wire is adequate because we’re used to seeing 0 or 1 AWG wire connected to 12-volt starter batteries. But this isn’t the same application as a starter battery.

Last edited 10 months ago by OverlandingSprinter
JunkerDave
JunkerDave
10 months ago

Maybe the existing wire can (barely) handle it. But if it’s getting hot, you’re losing energy there making heat instead of making the wheels go ’round. You don’t want to go to 0.9HP just to have a cabin heater.

Defenestrator
Defenestrator
10 months ago

10AWG would be good to more like 30A, but if it’s an extension cord it’s more likely 14 or maybe 16. Pushing it, especially at 16.

Crank Shaft
Crank Shaft
10 months ago

If it were 10 gauge, 30 amps would be okay. No idea of the exact draw on the Changli, but I’d guess it peaks closer to 50 amps given the voltage, motor power, controller efficiency, etc.

I am not an electrician, but I calculate Torch should be using 6AWG in this case. I’m guessing it used 8AWG from the factory, but as we know, that was not adequate.

Could someone double check my work here?

OverlandingSprinter
OverlandingSprinter
10 months ago
Reply to  Crank Shaft

You’re probably right. Electric motors require a lot of current to start. I’m guessing the Changli’s motor is rated at 1 KW nominal, but some multiple of 1 KW when starting. The wiring would need to be spec’ed to the peak current.

Drive By Commenter
Drive By Commenter
10 months ago

Xwhatever to rewiring that mess properly with actual cables. Old extension cord is janky even for a Changli.

Hoonicus
Hoonicus
10 months ago

delusional, unpleasant little troglodyte who looks like what a poorly-shaved chimpanzee would resemble if no one was willing to provide it with decent clothing
How dare they! We all find you quite pleasant!
But for real, as many have said, Get some proper cable!

notoriousDUG
notoriousDUG
10 months ago

You need to get proper sized cable for those; you are risking not only fire but damage to the motor controller with the irresponsible setup you currently have.

You can also figure out your range by comparing the amp/hour rating of the batteries to the old ones or to the average draw.

Sid Bridge
Sid Bridge
10 months ago

This is cool, but it’s not “Fill that battery compartment with AA batteries and see how far you can get” cool.

Defenestrator
Defenestrator
10 months ago
Reply to  Sid Bridge

I think you’d need around 1300 of them to push enough power, which in bulk would be something like $300. Not as bad as I expected. Building a ~30P43S bank of them sounds pretty painful, though. Especially when the whole thing has to be replaced every few hours of driving. You could go rechargeable, but then it’s more like 54S and $1500.

Andy Individual
Andy Individual
10 months ago

You should have had DT run the battery tray through his dishwasher for you so that you could eat out of it.

I’m not familiar with marine batteries. How do they get recharged? Do outboard motors have alternators? I know my sailor friends get shore power at their marinas, but cottagers usually leave their boats at the shore through the season. My father in law used to put the battery on a trickle charger/maintainer for the winter at his old place. Did that mean it had enough charge to last the entire boating season?

Also, even some cheap 14g romex from the home centre is a better choice of wire. Heck, spend a few cents more and go 10g. You can buy it by the foot. It’s not that hard to wrap around the terminals securely.

ThatGuyWithaFiero
ThatGuyWithaFiero
10 months ago

Romex is perhaps a worse choice, that’s still not enough wire gauge, and solid wire is a no-go for anything exposed to vibration like this is.

Andy Individual
Andy Individual
10 months ago

As I understand, solid wire is less prone to overheating. As for the vibration issue, soldering lugs on would probably be advisable with either type of wire.

What kind of amperage is this system outputting?

OverlandingSprinter
OverlandingSprinter
10 months ago

Hard no on solid wire in this application. No, no, no. If you need extra insulation on wire — this application would certainly qualify — then use Ancor marine grade wire. I use Ancor in my van build and it is, in a word, wonderful to work with.

Bracq P
Bracq P
10 months ago

There is a charge system much like the ones in cars

Andy Individual
Andy Individual
10 months ago
Reply to  Bracq P

Thanks, but I guess unlike a car, it does not provide accessory power? Hence the need for continual power draw?

Chartreuse Bison
Chartreuse Bison
10 months ago

The pumps and lights need to keep running when the engine is off

Cerberus
Cerberus
10 months ago

A lot of smaller boats might have accessories that will draw more than the modest alternators a smaller outboard would be able to provide and some of them will also need to be run with the engine off. Often in those cases, they’ll run two batteries: one deep cycle for accessories/backup, one standard for starting. The DC could be recharged at home or at a dock with power or, if there is enough surplus power in the charging system of a particular boat, they could be charged underway.

ADDvanced
ADDvanced
10 months ago

Torch, Sorry about the battery sponsor deal falling through. I know I mentioned it a few times in the last few articles, as LiTime/AmpereTime sponsored my solar shed build. I’d hate to find out my suggestion delayed this project, they have been good to work with but I have only worked with them once.

Glad she’s on the road again. I would go on amazon and order wire and terminal clamps, like so (this is exactly what I used in my solar shed build):

4AWG wire, 25′ of red and black: https://amzn.to/49dNNzv

Wire Crimper/Cutter for large gauge wire: https://amzn.to/46TXq51

Batter Terminals: https://amzn.to/3SijLVp

This should allow you to safely wire your batteries, and likely get more power/range out of your existing system, due to less loss. That heat you feel means the wiring is too small, and best case it’s hurting performance, worst case it starts melting and causes a fire. As someone who’s experienced an electrical fire while driving before, I highly suggest you spend the $70 or so to avoid this. Cheers!

Defenestrator
Defenestrator
10 months ago
Reply to  ADDvanced

Bigger wire yes, but maybe not that wire specifically. At 60V, it’s only about 17A so 10AWG would be plenty and easier to crimp. I’d also be pretty wary of that specific wire – it’s CCA rather than actual copper, and there’s no voltage rating on the insulation. Fine for car speaker wire where the frequency might be high enough for skin effect to matter and voltages are lower, but for 60VDC it’s iffy. Going all the way to 4AWG should more than make up for it in terms of capacity, but in that environment I’d worry about galvanic corrosion.

Elhigh
Elhigh
10 months ago

A couple of years ago my son and I bought a GE Elec-Trak E20. This was an electric garden tractor, generally deployed as a mower, built in the 1970s. The E20 was the big daddy of the range, described as the equivalent of a 20-hp “super” garden tractor.

That might be a little ambitious, but I can tell you that despite the nominal 2hp rating on the drive motor, the tires slip before the motor quits. And with a 36v battery pack and analog motor controls, it provides more speed control via a four-speed mechanical transaxle.

When we first got it, it had a newish pack of 6 6v golf cart batteries. The combined weight of the batteries was nearly 400 pounds.

Last year, we found a 36v litihum-ion EV pack, a takeoff from a Ford Fusion plug-in hybrid. It perfectly fits the rear battery box on the E20, like it was made to go there. With all the golf cart batteries out and the Fusion battery in, the tractor now weighs only about 650 pounds (down from nearly 1000), has considerably more range than even when the LA pack was new, and the steering is WAY lighter than when there were two big six-volts in the front of the tractor. Nick reports it’s downright light now.

My point is that you might want to consider changing to a completely different battery chemistry.

Isis
Isis
10 months ago

Those wires are way way way too small, especially for the repeated inrush currents of stop and go driving.

Toecutter
Toecutter
10 months ago

How much did that new battery pack cost you? You might have been able to put together a LiFePO4 pack that is much lighter, offers the same voltage, and even more range for the same or less cost. I tried to give you some pointers in earlier comments, but they were not heeded.

Also, those marine batteries are not true deep cycle batteries. If you regularly use more than 50% of their capacity or ever leave them deeply discharged for more than a few days(even once), they will not last. I predict that at least one of them will be dead within 1 year. If you were going to use lead acid, you should have gotten true deep cycle batteries rated for hundreds of cycles to 80% discharge without failure, like say, the Trojan 24TMX, or Exide Orbital XCD.

I could have helped you come up with an inexpensive LiFePO4 pack too. The 1.5 kWh pack I racked up over 20k miles on my electric velomobile with over the last 2.5 years still works and it cost all of $200(I’ve since upgraded). In the Changli, this 1.5 kWh 46.8V/31AH pack would probably give a 20 mile range and weighs all of 19 lbs, albeit, it is 46.8V instead of 60V so there’s an assumption that it could still run the car. And it’s a true deep discharge capable battery.

One of these would probably have set you right for a 40+ mile range and a massive weight reduction:

https://batteryhookup.com/products/new-51-2v-60ah-3-07kwh-lifepo4-battery-with-bms-48v

…under the assumption that the low voltage operating range of this battery would still be allowed by your controller. You’d need a different charger though, but there are LiFePO4 chargers in the sub-$100 range that could do the job.

In any event, glad to see you have it operational again.

Last edited 10 months ago by Toecutter
Cerberus
Cerberus
10 months ago
Reply to  Toecutter

Scrolled to see if this site was suggested for lifepo4 knowing you’d beat me to it. They get some seriously good deals on there and there’s quite the variety. Of course, you can’t always count on what they’re going to have, but that’s kind of the fun, IMO.

Toecutter
Toecutter
10 months ago
Reply to  Cerberus

You certainly have to know what you are looking at. You could easily get burned. I haven’t, yet.

J Hyman
J Hyman
10 months ago
Reply to  Toecutter

Dude, just how many future articles are you trying to deprive us of?

Defenestrator
Defenestrator
10 months ago
Reply to  Toecutter

I’d expect the car to perpetually complain about the battery being dead at 48V, but still run. The lack of voltage drop under load would make up some of the difference, but depending on how it feeds the motor (that is, if input voltage affects output) it could lose about 10% power that it really can’t spare. Probably better to stick with 60V nominal.

Toecutter
Toecutter
10 months ago
Reply to  Defenestrator

That’s a good prediction regarding how the car would behave at such a low voltage.

It would lose 10% power, and lose more than 10% of mass. Top speed would probably lose 2-3 mph, but it would accelerate significantly faster.

Another possibility is to order three 6-packs of these LiFePO4:

https://batteryhookup.com/products/new-case-with-6x-3-2v-74ah-lifepo4-prismatic-cells?variant=43706622902434

$630 + shipping, plus a charger would allow him to arrange a single string of 18 of the 74AH batteries in series for 57.6V nominal. The pack would weigh 86 lbs. If all cells are initially bottom balanced to within 0.001V, when configured as a single series string, no BMS is needed with this chemistry. As long as the connections are consistent between cells, it may never need another balance again for decades. It would be a 4.2 kWh pack and the Changli would have a 60+ mile range. The Changli would retain all of its original power, and then some thanks to less voltage sag under load, and it would lose hundreds of pounds of weight. And its fire risk would be almost non-existent.

I’ve got a working spot welder and a bunch of spare Panasonic NCR18650GA laying around. With a suitable BMS and charger, I could inexpensively build a 60V nominal 3 kWh Li Ion pack weighing roughly 30 lbs that would give an honest 40+ mile range in the Changli. It would be a much bigger fire risk than the lead acid pack the Changli has, but it would only take up about 1/3 the space of the Changli’s battery box and it would lose hundreds of pounds. Further, the capacity of a Li Ion battery pack is not penalized as much by Peukert’s effect as lead acid batteries are, so nearly all of that 3 kWh would be usable capacity.

Last edited 10 months ago by Toecutter
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