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!
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.
This is above my pay grade and ability so I will settle for asking a question. Do you need exact terminated cables or exact terminal related cables? Just wondering.
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.
Looking at your emoji, I suspect you are a dog “person”. Does that perhaps color your outlook on cats in general? I suspect so.
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.
How did you come to name your cat “Tomato”?
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.
Sounds like the timer ran out.
Find the coin slot and insert another quarter.
Buy, borrow, or steal a resistive battery load tester and independently check each battery. I’m with the others that think one of your batteries is toast.
“Because I’m not some Internet Shadetree…”
In my defense it’s a mature Douglas fir, so it’s a rather nice shade tree.
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”.
And the Rich would want to diesel convert it…. see their current project ‘Model D’.
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?
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.
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.
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”.
Did you really just twist and tape that wire together on a 63V system? Crimp or solder them together, please, for the love of god.
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.
“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
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.
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.
Agreed. And cats pee on everything. Feline urine and batteries do not mix.
Footnote: That also explains that funky smell in the ‘Li. This whole time you thought it was Otto.
Let’s not forget other possibilities of rodent or animal damage don’t just blame tomato.
I want the ‘Li to be healthy and working, I really do.
But what we all really want, what we need, what we DESERVE is more Tomato content!
I see a guest columnist opportunity here!
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.
Bwahahahahah. Cook the goat/chicken under the hood of an XJ.
I would also look into rustproofing it since DT was close to it.
Why are sacrifices always a goat or a chicken? Why does no one ever sacrifice a porcupine or a skunk?
“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.
Now this is worth fixing. Great article.
So the original shoddy tape work was something of a sacrificial element?
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.
– 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.
The rack is also bolted so probably okay
With China bolts I recommend some thick (China) cable ties also!
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.
As other point out, check the Cells first.
Next, I forgot– is this a brushless motor with three connections, or brushed DC?