The Cheapest Car In The World (The Changli) Is Broken And I’m Stumped

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I want to preface this by reminding everyone that overall, my Changli, the Cheapest Car In The World, has been incredibly reliable. After about a year and a half of ownership, I’ve only really had one breakdown, and I was able to fix that with some electrical tape. This time, though, there seems to be something more significant going on, and I’m a little stumped.

Last week, the Changli was doing just great! David was by for a visit, and my kid Otto and David and I drove that little 1.1 horsepower Chinese electron-burner all over town. Zero problems, just good, honest Changli fun.

I was in Detroit for a week, and when I got back and wanted to take the old ‘Li out, I was met with a pretty basic problem: It didn’t want to move. And moving is something that I personally think is a real desirable quality in a car, even if you wouldn’t necessarily know that from looking at my driveway.

It turns on fine, dash display comes on, the voltage shows the expected number of 63 volts, but when I attempt to drive, this happens:

Hear that weird pulsing? It sounds like some kind of strange, intermittent short, maybe? Like the motor is being stopped and started over and over. I checked back at the motor assembly itself to confirm, and that’s what it seems to be doing: pulsing on and off, I think. Here, look:

It’s funny to me that I still asked my kid to hit the “gas” even though, of course, there’s no gas involved here. The sounds and motion do kind of remind me of a poorly-running small gasoline motor, but that’s just a silly coincidence.

I checked the under-seat battery area again, where the problem was last time, and did find some evidence of a similar issue to what happened before, in the Changli’s one breakdown:

Something is still causing this wire bundle to heat up and melt things and cause problems. Last time it just melted its own tape off and came disconnected; this time, because of my better-than-factory twisting and taping skills, the bundle stayed together, and instead actually got hot enough to melt through the plastic battery handle, which isn’t great.

The picture up there shows the condition of things after I un-taped and disconnected things. That revealed this:

So, the heat had melted the insulation, and two close wires ended up with bare wire touching, causing a short. I thought this had to be the issue, so I got everything apart, cleaned up, taped up the exposed wiring, and figured that’d be it, but no luck. Still the same pulsing behavior.

So, now I’m wondering if maybe the short fried something in the motor controller? And, is the motor being pulsed on and off, or is it possible it’s getting polarity reversed over and over?

I tried in forward and reverse, and each time I got a small motion in the selected direction before the rhythmic pulsations began, so I think it’s at least moving in the right direction.

I’m not exactly sure how to diagnose this; I suppose I could try to put 63 volts directly to the motor and see if it spins normally, bypassing all of the controls in between, and confirm that the motor itself is okay.

I can also open up the controller and look for obviously burned/charred/etc. components. I didn’t see any smoke coming from them, or smell anything too odd, though as I type this I think I recall smelling something as we drove last week.

But, like the legendary ads say, it ran when parked. What changed? It’s been pretty wet here, and water conducts, so perhaps that was a factor?

I may try to reach out to Changli, too. After all, they kinda owe me for all the good publicity I’ve given them, after all. They even have me on their Alibaba page. They can at least hook me up with a motor controller, right? I mean, if that’s what this is.

So, right now, the Changli is just an expensive bed for my cat, Tomato:

It needs to be more than that, I think. If there’s any electrical or EV engineers out there who may have an idea how to best diagnose or fix this, I’d love to know! Tell me in the comments, and if you need more pics or video or whatever, I’ll get it to you!

I use this silly thing a lot, I now realize. I want it running again!

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128 Responses

  1. Torch, is the roof rack on the General ‘Li actually being held on with zip ties?
    Come on, man. For real “utility truck” action you could at least bind it down
    with bailing wire.

  2. Look it’s a used car, do the smart thing. Sell it for 25K, order a new Changli for 2K, wait a few months for it to arrive and you’ll come out way ahead, Heck, you could even start a fresh series about the new one. Content!

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      1. This is my guess. I totally get it sounds like a starter with not enough power just clicking, but if that were true you’d think the whole car would shake. The fact that the motor is shaking but the car isn’t moving to me means the chain is broken or something stripped and is beating around in there.

  3. The BMS could be toasted from the short or the motor controller itself. From the way its acting and still turning on I would think the motor controller. You could test for appropriate voltage. I think if its toast then you buy a wrecked model 3 and drop that drivetrain in the Changli.

  4. If the motor were simply pulsing on and off I’d expect to see slight movement of the vehicle. This looks and sounds like something may instead be physically broken in the drivetrain and you’re getting a chattering of broken metal against broken metal. If you separate the motor from the axle unit, you may be able to check whether (1) the motor then spins normally when power is applied and (2) any damaged components are visible. At least that’s the first thing I’d check.

    1. Yeah, this is something I would look into as well. It certainly sounds like a gear or a spline is slipping. In the video posted your speedometer claims that you are moving when sitting still possibly supports this (I’m assuming the gauge reads the engine speed).
      Though I wouldn’t doubt that there is something possibly wrong with the electrics as well, based on the overheating wiring.

      1. Yeah, none of the other theories explain the bogus speedo reading. _Something_ in the drivetrain is moving fast enough to convince the car that it’s doing 24 kph.

        Which, incidentally, is probably the fastest 0-24 run a Changli has ever done, even if it is complete nonsense. 😉

    2. Torch, I’d check the possibility of mechanical failure as per the above first, if possible. If anyone can diagnose a fault in a ‘so bad it’s good’ car and get it running, it’s mdharrel. (seriously – check his collection. Please. I beg you. You will want to thank him for keeping the unusual and mostly unloved, alive. Well in various states of semi-functionality at least. Which is the best sort of functionality I think you can hope to achieve when you’re talking… the sorts of cars for which mdharrel has an affinity.)

      Just be very careful, there’s potentially (see what I did there) very high fault currents running around those things.

      If it’s not the above mechanical issue, then it sounds as if the controller is fried. Electrically speaking, an electric motor at zero RPM is a dead short. Put an electric motor under load straight across a battery/power source without a suitable controller or resistor, things tend get hot or go bang – usually at the battery end. That’s why controllers exist in application where high loads or variable speeds are required.

      Which is why my take – if the problem turns out to be electrical – is that the controller is no longer able to control the power to the motor adequately. I think maybe it’s overloading then shutting down with every attempt to send current to the motor, then trying again, then shutting down, trying again, shutting down etc. – hence the ‘chattering’ that you’re describing.

      1. Editing to add another (again electrical) possibility – when the battery voltage drops that much when under load, it’s can also be a sign of a dead battery cell. It’ll show full charge with no/minimal load, but the higher internal resistance of the battery means that the voltage drops a lot to try to deliver the required current for turning the motor.

  5. i guess i should explain the noise.. if your battery(s) have a dead cell, when you attempt to move the car you apply a large load to that battery back, the voltage drops precipitously, which will cause the motor controller to drop out, then voltage recovers once the load is no longer there. wash, rinse, repeat… you should be able to see that on a scope (if you have one) or a multimeter connected to the power input to the motor controller. you can also pull and test each of your batteries. they look like 12V SLA, so you can take them to an auto store and convince them its a lawnmower battery. in all likelihood your motor and controller are fine. first rule of electronics diagnosis, ensure your power is fine before suspecting anything else.

      1. yes, provided its quick enough to register the changes. you can do once battery at a time to figure out which one it is. also… you can lift the drive wheels and see if it can spin those at all. if it can, its almost certainly a battery/power issue.

        1. perhaps a more fun way to diagnose the batteries is with a sealed beam headlight. i know you have one, probably hundreds. you can connect one to a single battery and see just how quickly it gets dim. if the a SLA battery has a bad cell it’ll usually go dim(mer) in less than a minute, while a healthy battery will be able to power it for quite some time.

      2. Let me reiterate the importance of getting that wiring sorted out safely. Simply put, that car is a fire hazard, and your insurance company will find your blog posts if things go south. There is enough current in that little BEV to weld. If you’re uncomfortable sorting out that wiring mess, I’ll gladly help you do a proper job, even if that means flying out to that sweatbox you call home. You are too valuable to cheap out on the world’s cheapest car. rootwyrm is basically correct, if not a bit alarmist. you may very well have dead batteries, but that wiring is a one-way ticket to a blog post titled “the world’s cheapest car destroyed everything i own”

        1. When I was a little younger I used to race 1/10 scale electric remote controlled cars. They run on 7 volts and would have spontaneous combustion of the electronics if they were not sorted correctly. Toledogeek is absolutely correct here. That wiring is a disaster and makes me nervous for your cat.

      3. Disconnect all the batteries and check the voltage on each one. They should all be within +/- 1 volt of eachother.

        If one is way off, that’s your dead battery.

        If it this tests normal, put the voltmeter across all the batteries and note the voltage. Try the go pedal, if the voltage drops more than 20%, all the batteries are toast.

        Even if it looks like only one dead battery, I’d replace them all. If you do decide to only replace one, make sure all the batteries are charged to within 1 volt (after sitting for an hour off the charger). You’ll make the batteries much happier this way.

      4. Suggestion: use a multimeter to measure the resistance of each battery. They should all be close. If one of them isn’t similar to the others, it likely has a bad cell. You will need a large resister. There are guides online on how to measure this.

        https://www.instructables.com/How-to-measure-the-internal-resistance-of-a-batter/

        Alternatively, you could have the drive wheels lifted, and see if it spins under light loading. If so, find a way to keep the load steady(perhaps a brick under the accelerator), and look for consistent current/voltage values. While putting it under load, measure each battery’s voltage. If one of them drops to a lower voltage than any of the others, you’ve found a battery with either a bad cell or bad connectors/cables.

        1. A broken battery will show an infinite resistance and 0 voltage.

          Now seeing how burned the cabling is, I’d recommend to replace all the power cables by cables from a bigger gauge.

          If a cable heats enough to melt it’s insulation it means that too much power ( amps ) for the gauge is going through the cable. ( I burned a few at university learing about electrical motor powering long ago. )

          1. A cheap $8 multimeter from Harbor Freight or some other crap hardware store will do the job.

            A friend of mine converted a Mazda B2200 to electric back in 2010 and had a similar problem. The truck would see a massive voltage dip and then shut off even under light loading. I immediately knew that it was a high likelihood he had a bad battery. We located the bad battery, removed it from the series string, and the truck ran as good as it used to. It was a 168V conversion using Marine batteries, and we dropped it to 156V, so the performance loss wasn’t noticeable. It also had no BMS. I advised him that he was also using the wrong kind of batteries for the application and to replace them ASAP, which he did. Unfortunately, that truck got totaled 4 years later by some yuppie wrecklessly test driving a Porsche who broadsided it at a high rate of speed.

            If Torch has a bad battery and locates it, it is very likely the Changli will still run with it removed, depending upon the minimum voltage parameters the controller is set at. Although, he’d want to replace the bad battery ASAP, because his range will be crap(moreso than it normally is) before the controller and/or BMS shuts off. And it shuts off to prevent damage to the transistors and other components. Being that the batteries in the Changli are lead acid, and a single series string, it really shouldn’t need a BMS.

              1. Isn’t the Autopian “powered by Optima?” This seems like a great promotional thing. Get an Optima rep out there, make a video, talk about differences in battery types and quality. Involve your sponsor! And slap a “Powered by Optima” sticker on the Changli.

                1. this is absolutely the right approach. this would be a great way to involve your sponsor in the story, get the changli up and going, and increase its performance/endurance/safety and create a bunch of content at the same time. everybody wins here.

  6. that wiring looks rough, not to mention unsafe. you should really separate the positive and negative wires in that loom from each other before they start a fire and burn your house down. use some split loom if yer feeling lazy. or just rewire it properly..
    the battery casing is showing some warping, so i’d suspect that you have a battery with a dead cell. the voltage will look fine but drop a ton when there is a load. i also suspect that you left it on the charger while you were gone, which could have boiled the electrolyte right out of it. need more photos!

    1. I didn’t have any idea except take it to your local Changali dealer. Hey one year must still be under warranty. But this comment reminds me of an issue I had with my ICE when doing some wiring on my JH had the wiring melt the 2 wires together in several places. I found and fixed 1 but still had the problem more investigating showed 6 spots where pos/neg had melted together.

  7. 1) I wouldn’t trust any of the high load carrying cable you’ve pictured – the insulation is damaged quite badly. It needs to be re-wired with good copper wire.
    2) A good (or cheap) IR camera would help some diagnostics with bad connections if you’re not handy with a DVOM – Given the projects on the site it may see a lot of use?
    3) What changed was probably the carting of 3 people vs the standard 1 or 2 – you likely pulled a LOT more current from the batteries in your jaunts about town. High current and temperatures would make the batteries, wiring, motor, and controllers the first place I’d start poking about.
    4) Be careful with the 60V+ system – do a quick amount of research – this is is not considered low voltage (which is less dangerous). We all want more non-hospital related content.

  8. Just to reiterate what many others have said, get that wiring issue fixed properly before doing anything else. Also, be very careful. Many people think that because it is battery power, it is not dangerous. There is more than enough current and voltage in those batteries to kill you. If the batteries got that hot (hard to tell in picture) you should replace them regardless of what the voltage / current says.

    As my professor once told me; “There old electricians, and bold electricians, but there are no old, bold electricians”.

  9. Yep, it’s busted. The direct to the motor is the next good step. That will tell you where the fault lies.

    While it may not work as a car, the cat approves of the bed. When you have a cat, you are not the owner rather a manservant.

    I must stop typing now as my two masters are hungry and need food.

  10. Maybe I missed something but that acts like a loose/worn/corroded/burned connection somewhere.

    Voltage reads fine across it because there’s almost no current involved so it doesn’t take much of a connection to read good voltage. Just a whisker of a conductor or the tiniest little contact patch on a connection will provide enough contact for a good reading on a volt meter. Then you try to draw seriours current across it but the resistance in the bad connection is super high so the voltage is low, resulting in the meter suddenly giving you a properly low voltage reading. The connection heats up from the resistance, which causes the resistance to increase, which causes more heating, feedback loop, till the conductors become so warped from heating they break contact, allowing the conductors to cool and settle back in place where they make contact, poorly, and start the cycle over again. Meanwhile the high current is melting your puny wiring harness which wasn’t designed with this level of current in mind.

    Or it is a bad connection with an entirely mechanical presentation. The tiniest bit of contact gets a reading, then you hit the power and things move and the bad contact breaks, resulting in loss voltage reading and of current carrying, resulting in propulsion dying, resulting in things going back to their resting state, resulting the the connection being made again, things move and the bad contact breaks, etc, etc.

    BTW, bout time for some fuses before you burn that thing to the ground, no?

    1. I doubt this is it because you wouldn’t be melting wires. The high resistance caused by worn out connections/wires would cause the current to be low, not high. The melting is from excessive current draw – most likely the engine or some of the high-current electronics in the motor controller are burnt out. Unfortunately, those are the most expensive parts on the car.

  11. Hmmm….The Autopian partners with Rich Rebuilds to diagnose and fix the Changli?

    Then maybe Otto won’t sound so much like he’s rolling his eyes when Dad asks what he’s driving, and he has to say “the Changli”.

  12. Jason,

    As many others have said it could be a bad battery, which is a good place to start. As far as hooking the battery directly to the motor you need to determine if it is a brushed DC motor which will spin with a direct battery connection or a Brushless DC motor BLDC, or induction motor which require a sinusoidal AC signal to drive the motor. If it is an AC motor and you hook up DC voltage to it you will cause significant damage to the motor and batteries. An easy way to check this is to trace the wires going into the motor back to the speed controller and check if there are 2 or 3 wires connected to the motor. Two wires means brushed DC, similar to an automotive starter, 3 wires (or more) indicate it is an AC motor. To check the electrical health of the motor, check resistance between all 3 pairs of wires for an AC motor and verify they are close to one another and then check the resistance between each wire and the motor case and verify it is not shorted.

    To check the health of the speed controller (motor controller or inverter) you can disconnect it from the motor and connect the the 3 leads to an oscilloscope and look for sine waves (or square or trapezoidal) when the throttle is pressed.

    I work as a power systems engineer at Ampaire where we are developing hybrid electric airplanes so if you need any help feel free to reach out.

  13. Jason, just an FYI – outdoor cats are terrible for the environment as they decimate native wildlife and spread disease through their waste. I’d recommend bringing your cat inside and maybe build a catio.

      1. Nope. Cats are the #1 human caused killer of birds, and they kill tons of other native wildlife as well. I don’t support people letting their dogs roam the outdoors, but in most places that’s not allowed anyway.

  14. Remember, lower voltage means higher current. In order to maintain the voltage the current is being raised. Happened to several older ford trucks I’ve owned. Weak battery equals low voltage/higher current draw which welded the contacts on the starter relay; which results in constant crank which means lightening quick disconnect of the battery before everything melts down. Fun times.

  15. “Jason, just an FYI – outdoor cats are terrible for the environment as they decimate native wildlife and spread disease through their waste.”

    By that logic no human should ever be allowed outside ever. Hope you like the great indoors.

  16. Pulsing and grinding noise, you say? Don’t ask me – my only suggestion would be similar to this classic Peanuts comic (republished today, coincidentally):
    Charlie Brown: You think my dad doesn’t know anything about cars? Yesterday he heard a strange grinding noise coming from the engine.
    Linus: Don’t tell me he stopped the car and fixed it.
    Charlie Brown: No, he just turned the radio up louder so he couldn’t hear it.

  17. Jason – the reason for the failure is quite simple. You are experiencing planned obsolescence from a car manufacturer that couldn’t build a reliable lawn mower. You definitely got what you paid for. Recycle everything you can, throw away the rest.

  18. Before you troubleshoot the mechanical you gotta take care of the known electrical problems.

    1. Disconnect all the batteries and have them tested under load. Seeing the voltage plummet under load in the video I bet you have a bad battery in your string.

    Whatever is causing the excess current draw has also severely damaged the wiring so….
    2. Do NOT re-use those wires. Do not repair those wires. Do not temporally splice those wires. As others have said. lower voltage = ALL THE CURRENT. Fix the obvious problem correctly that way when you troubleshoot further you know for certain it isn’t your “fix”.

    If you want to keep the Changli (please do) then get rid of those power wires and replace them. If get got hot enough to snap then odds are they’re toasted elsewhere as well. Also invest in an appropriate sized automotive breaker so the new wires don’t run the risk of burning/overheating.

    3. If the batteries and wiring is happy I would lift the drive axle off the ground and see if you get the drivetrain to move and move without protest.

  19. its definitely mechanical, not electrical. well electrical too, but that’s not what causing the rattle and not moving…
    the hub or whatever it is has its cheap metal gears stripped.

    too much weight was on the car due to David 😛

  20. Just to echo many others, that electrical shit needs to be fixed NOW! It’s clear they used the minimum gauge wire and that it should be replaced with a heavier gauge. Do that first.

    Second, the current problem (see what I did there?) sure seems like a purely mechanical failure. Broken gear or spline. Changli should certainly be able to ship you replacement parts.

    Or maybe just buy a new one? They sell these for so little it’s almost a sane option in today’s vehicle market.

  21. “David was by for a visit, and my kid Otto and David and I drove that little 1.1 horsepower Chinese electron-burner all over town.”

    “though as I type this I think I recall smelling something as we drove last week.”

    No doubt followed by waves of uncontrollable laughing

  22. So now, in addition to worrying about DT catching tetanus, we have to be concerned about JT getting electrocuted.

    Be safe out there guys…

    Unrelated and only half joking. How many miles is the manufacturer’s warranty for this thing?

  23. When a friend of mine was studying to be a motorcycle mechanic 25+ years ago, he used a book. to help him understand electricity. This book recommended viewing electricity as little green guys chasing little green girls. Perhaps your little green guys and girls escaped.

  24. My god, David lives on rust and ATF, and Torch hasn’t washed a car in years. No wonder the xB is a Petri dish. Perhaps hire a tall person to wash the roofs of your cars. Poor VW Beetle.

      1. I have seen mung like that in Oregon. Yeah, pollen makes cars instantly dirty, but what I see is base neglect, a combination of dust, biofilm, pollen, mildew…
        The Scion xB. It grew stuff on the interior. Gross.

  25. A great and little-appreciated benefit of being a popular automotive writer: 101 experts at your beck & call for the odd car problem — or is that: a problem with an odd car?

    BTW, in my uneducated opinion, the electrical guys have a much better and more fully-developed diagnosis than do the mechanical types. (Check the batteries first.)

  26. You need to fix that wiring correctly before you do anything.

    Jack the rear end up and try it with no load. It really does sound mechanical, and this will immediately rule that out.

    It would not surprise me if that control display does not have some diagnostic screen, even if it is in Chinese, instead of Blinkurium.

    Somewhere on that thing will be a sticker with some form of ratings. Replace the wire with proper wire rated to work with what it tells you on that sticker.

    Oh, you probably have a pinch point on those wires…. fix that too. You had lots of back seat passengers crushing all of that.

  27. I’m not gonna act like I know better than other commenters on this but I do know.. wire burning once on a Chinese appliance, not surprising. Wire burning twice on a Chinese appliance, that’s a problem.

  28. I can’t remotely fault seek your car, but I also think, that when it’s running again, you should replace all the shoddy wiring with some proper thick EV wiring! Preferably orange of course, so it looks like an expensive EV 🙂

    There was an Edd China episode on YouTube recently, where he made a proper thick wiring loom for some EV (was it the Ice Cream Van?). That looked very good. Just for inspiration.

    1. – And do get some thicker cable ties for that roof rack! For Tomato’s safety 😉

      Drove some years with two ordinary galvanised 1/2″ water pipes tied to the side bars of my Citroën BX 19 RD Break with metal straps (the kind you use for coolant hoses). That held hundreds of kiloes of all kinds of crap.

  29. 1. You let DT ride in the Changli
    2. The Changli is broken

    You will need to consult with a shaman and exorcise the DT demons out of the Changli prior to it ever running again. It may be necessary to sacrifice a goat or a chicken, or both for anything in that car to ever work properly again.

  30. You know how cats jump on the keyboard to keep you from interacting with the outside world?
    I’m guessing Tomato is pissed that your were gone for a few days and has somehow sabotaged the ‘Li to keep you from leaving home again.

    1. “You need to do a full reset: Turn on the power, set the turn signal to left, turn on the wipers, push the horn button 3 times quickly, press the accelerator once quickly, turn off the power and hold the steering wheel firmly for two minutes. Now turn the power back on, set the turn signal to right, turn on the lights…

      I love fucking with these Americans. What are they going to do? Come after me? They don’t even know where Hyderabad is.”

  31. Oh god. I was out at a cruise-in and then beer shopping.
    So. Hey Torch.
    I can tell you exactly what’s wrong.

    I wish I’d known about the melting cables post-initial repair because I would have warned you to immediately disconnect them and do a dead short test. And now it appears to have completely let go internally. Now, hypothetically, you could replace the motor. Absolutely.
    1HP motors are not at all hard to find, in fact. There’s two problems though.
    One, you need one with the exact same bolt pattern. That might not be too hard in and of itself. It’s probably a very common part. Hell, it’s probably just a standard face mount NEMA setup.
    Two, it needs to be a 60 VDC 1HP motor identical to that one. NOW you have a problem.

    If you refer to your own handy article on how cheap Chinese LSEVs are made, you have a great photo of what’s going on in the motor. Most likely the shaft broke or it just was poorly epoxied together or take your pick. That internal short’s what destroyed your electrical. Remember, the 6/12V’s separate from the motor load, so it’s probably been protected while the motor itself’s been melting your everything. And as you yourself said: motors are available in a staggering number of variants. So you’ll need to find one that fits exactly. Or that exact motor.
    Oh, and be able to order it in quantities less than 1000.
    So yeah, if Changli can’t help you directly (who knows there) then you’re really up a creek.

    Because I’m not some Internet Shadetree, The Mandatory Disclaimer:
    YOU ASSUME ALL RISK WORKING ON THE VEHICLE. YOU WILL BE WORKING IN DIRECT PROXIMITY TO AND WITH ELECTRICITY WHICH CAN MAIM, INJURE, AND KILL YOU. AND IT WILL HURT THE WHOLE TIME. SERIOUSLY. DO NOT FUCK AROUND WITH THIS SHIT, BECAUSE YOU WILL FIND OUT. IF YOU ARE UNSURE OR DIRECTIONS ARE UNCLEAR TO YOU, DO NOT PROCEED! I’M SCREAMING BECAUSE SERIOUSLY, SKIPPING STEPS WILL GET YOU KILLED HERE!

    Unfortunately, this one is easy to confirm. Grab a DMM. Select continuity mode. DISCONNECT ALL POWER SOURCES AND BATTERIES OR YOU RISK INSTANT DEATH.
    Red lead to the positive battery cable, black lead to the motor – make sure it’s to an unpainted area, preferably with minimal corrosion. IF YOU HAVE CONTINUITY, IMMEDIATELY REMOVE ALL POWER AND DO NOT APPLY ANY POWER. That indicates a dead short to ground and the vehicle is absolutely unsafe to have any power in. It’s a fire risk and an electrocution risk.
    If you do not have continuity, switch to internal short testing. Connect to the positive and negative inputs on the motor and select resistance mode. Low resistance means the motor is okay. Anything over 100 ohms, FULLY DISCONNECT, REMOVE, AND UNDER NO CIRCUMSTANCES APPLY ANY POWER TO THE MOTOR. It has internally shorted to an open circuit and is a fire and safety hazard.
    If that passes, next select continuity. Red lead to motor positive input, black lead to the motor chassis NOT the motor wiring. If you have continuity here, UNDER NO CIRCUMSTANCES APPLY ANY POWER TO THE VEHICLE! The motor is shorting to chassis ground. This can potentially result in the ENTIRE MOTOR INPUT going to the chassis ground.

    If all of that tests good, well. It won’t. You have a short in there somewhere, period. That’s why the cables melted. That’s not just from loading. The question is where the short is and why. That MUST be addressed before anything else. If the short is the motor, then that’s the short. There’s nowhere else it can be that does not require immediate repair first. And even if it’s in the motor, again: immediate repairs required first.

    And Jason, I really cannot emphasize this anywhere enough: the car is not just unsafe right now, it is potentially lethal. Even discharged, the batteries are carrying more than enough amps to kill. You absolutely cannot ‘fix’ the cables the way you did. They have to be completely replaced and properly terminated. Until that’s done, the batteries need to be completely removed from the car.
    Even a slightly loose connection can cause these cables to get incredibly hot, melt through the jackets, and subsequently send all 63 volts and dozens of amps through the chassis. I’m not saying you need to go buy some $500 set of magic custom cables. But you must use properly sized and terminated cables with undamaged jackets. Past that? Make ’em blue and white or both purple or chartreuse for all I care. Just use proper gauges and proper crimps or solder-balls, okay? Harbor Freight sells perfectly adequate stuff for this. This is literally the biggest and most dangerous safety issue by far and away.
    So please for the love of all that is holy, understand that the BIG SHOUTY TEXT is because this is genuinely dangerous stuff and I am screaming my head off because I am fucking terrified that you are going to just fob it off as “it’s the cheapest car ever, I’m just gonna crank till it stops” and cause severe injuries or even death. Or worse, somebody with absolutely no electrical training is going to give you bad advice and get you killed. (Thankfully none of that so far.)

    If you need someone to help talk you through any of it, please reach out to me directly. I will MAKE time to answer your questions and help ensure nobody gets hurt anywhere besides the wallet and bruised knuckles.
    ‘Cause, uh, yeah. 63V 15A, 85% efficient… that’ll be 8 AWG copper minimum hardened weatherproof jacket (NOT low voltage battery wire, this is NOT low voltage,) but I’d prefer 6 for surge. It’s about $8/ft at McMaster-Carr – 7479K14.

    1. “Cause, uh, yeah. 63V 15A, 85% efficient… that’ll be 8 AWG copper minimum hardened weatherproof jacket (NOT low voltage battery wire, this is NOT low voltage,) but I’d prefer 6 for surge. It’s about $8/ft at McMaster-Carr – 7479K14.”

      Why not just use automotive starter lead and ground wires? Those are weatherproof and should be able to handle that kind of power just fine.

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