Sudden death and two months to replacement!

[rust]

OK, so I've been EV'ing it for a year and a half, had been dying to get into it for five years.

Year and a half ago I bought an electric bike at a local retailer -- no kind of documentation, instructions, not even what brands of motor/controller and so on. I felt kind of lucky to find one in this city even though this place is known for its bicycles.

Forget about SERVICE! Doesn't exist, and if I wanted to get some kind of servicing done, I'd have to haul the carcass into Santiago (two hours by train, more by bus) and MAYBE find some place that understands the binary language of moisture vaporators, which in this part of the galaxy, is not very common.

Anyway, back to our story: after the initial purchase --yes, they gave me a defective cell in the battery pack, which they replaced, I got to tooling around town in my all-steel bike (26"wheels, 36V 3x12Ah Pb, unknown controller, 250W unknown motor on the back), equipped with a cheesy squeeze horn (which people CANNOT ignore), wearing my bell helmet and enjoying the autonomy.

Then about six months later I had a pedestrian run out in front of me... sent me flying and put me in the hospital with four broken ribs, and were it not for my helmet, skull intact. Apart from the idiot prosecutor who had never heard of a pedestrian causing an accident, I came out of it alive. The bike had a damaged chain guard, BENT crank axle, and other scrapes and scratches. So much for my nice shiny bike. Obviously I couldn't ride it for a while because of the ribs, but I got it taken apart and went in search of a replacement shaft for the pedal crank (also known to the locals here as a unicorn horn). Well, there wasn't one. Nowhere to be found. It was more likely to buy ten winning lottery tickets for the jackpot in a row than to find the shaft. But... there were some turners in town. And I got it straightened pretty much. So I could at least pedal without the chain falling off.

I had to stop by the Medical Legal Service, so I got on my bike and got off to a shakey start. Totally ok, round trip about three miles. Better than walking. Next morning I went to take the bike out again, throttle wouldn't work. Son of a... tested it, yeah it had taken a pretty strong hit and it was a no-go. Ordered a new one off eBay. Two months later, it gets here and I get it installed. Everything okey-doke.

Months go by, and come September, I hit a steel grate a little too hard and it puts a good dent in the rear rim. Being a heavy guy (over a 100Kg), I figure I better get that replaced, so I took it to the local butcher shop. Actually there are probably two dozen bike workshops in just the downtown area here, so I take it where I've bought bike stuff before. Yeah, so he'll put a new rim on it installed for $12,000 pesos. Which works out to about 25 bucks. So I leave it with him.

I come back and the IDIOT has CUT the cable running to the motor! I was seething. Don't worry, he says. He's gonna solder it all back together. Come back two hours later, and he's still working on the soldering. He had to borrow someone else's soldering iron, paste, solder and replace the damn electrical plug. Forty-five minutes later he's finished. I put the key in and hey presto! it works!

Months pass by and no issues with the soldering job. But it worries me, just the same.

Monday I go into terminal's lunch room, kiss the wife, have lunch, stand in front of the fan to cool off (it's over 30C here, not unusual) and then outside to hop on the bike to go back to the house. Turn the key, nothing. Whaaaaa... Ok, key on, key off, nothing. Wiggle the power connector. Nothing. Check the LED's: on. Headlight? Working. Brake lights? Working. Crank the throttle. Nothin' honey. OK, so I hop on and pedal home to take a look.

Get on the Internet, check ebikes dot ca for the troubleshooting pdfs. Ok, so 5 volts to the throttle (everything else disconnected), check voltage on the return (in this case, it's a yellow wire, the old one was white) yeah, just about a volt at rest, and 4 and some volts at full throttle. CHECK.

Check the Hall circuit in the hub. OK, 0V, 5V, 0V, 5V etc., all three phases. Hall sensors OK. Re-did the suspect soldering job (this guy loved to do it wrong, but it was ok) using barrier strips.

Opened the no-name controller (sealed with silicone), nothing smells inside. Exterior wiring: nothing melted or scorched.

I also spun the wheel while measuring voltage: varying results (difficult to do alone while watching the meter) on the three phases while disconnected from the controller...

Checked for open circuit on the MOSFETS: they ramp down... I guess that's normal.

I'd like to check the three phases on the controller, but I can't seem to get a reading... shouldn't I be getting (equivalent to square tooth) something like an intermittent 36V or what?

*EDIT* I should mention that I charged up the battery pack and it shows 39.8V. Also, I checked the fuses (one in the battery pack, the other to the headlamp/LED indicator), all good.

But still I'm walking!

Any ideas, suggestions? HEEEEEEeeeelp.

Oh, and before I go, if it's the motor that's borked, can a 500W motor be put on a 250W controller without major issues?

 

[amberwolf]

Turn the key, nothing. Whaaaaa... Ok, key on, key off, nothing. Wiggle the power connector. Nothing. Check the LED's: on. Headlight? Working. Brake lights? Working. Crank the throttle. Nothin' honey. OK, so I hop on and pedal home to take a look.

Get on the Internet, check ebikes dot ca for the troubleshooting pdfs. Ok, so 5 volts to the throttle (everything else disconnected), check voltage on the return (in this case, it's a yellow wire, the old one was white) yeah, just about a volt at rest, and 4 and some volts at full throttle. CHECK.

Check the Hall circuit in the hub. OK, 0V, 5V, 0V, 5V etc., all three phases. Hall sensors OK. Re-did the suspect soldering job (this guy loved to do it wrong, but it was ok) using barrier strips.

Opened the no-name controller (sealed with silicone), nothing smells inside. Exterior wiring: nothing melted or scorched.

I also spun the wheel while measuring voltage: varying results (difficult to do alone while watching the meter) on the three phases while disconnected from the controller...

Checked for open circuit on the MOSFETS: they ramp down... I guess that's normal.

I'd like to check the three phases on the controller, but I can't seem to get a reading... shouldn't I be getting (equivalent to square tooth) something like an intermittent 36V or what?

You won't get expected output from it unless it is plugged into the motor and turning it, because it operates on feedback from the halls; if it doesnt' get any it probably shuts off, if you get nothing.

Does it feel "sticky" at specific points or have a high resistance to turning when turnign the wheel by hand either forwards *or* backwards (in the case of a geared motor), while connected tot he controller but not powered on?

If so, disconnect from the controller, and see if it keeps happening.

If so, the motor probably has a short either at the repair point in the cable or inside at the phase wires, etc.

If not, the controller probably has toasted FETs.


But if you get absolutely no response from the controller to throttle, my first suspect is the connection from throttle to controller (does it get the same voltages where the wire goes to the the PCB inside it?). Sometimes wires break off isnide controllers.

Often, connections get corroded and need to be unplugged and replugged (or cleaned and then replugged). Also, crimps on contacts are often poor, and may appear to be connected but fail later, either by wire falling out or by corrosion at the wire end of the contacts.

or a problem with the battery sagging too much when you try to run the bike, even though it works before that. (probably isn't this).

Oh, and before I go, if it's the motor that's borked, can a 500W motor be put on a 250W controller without major issues?

Probably, it'll just perform like the 250W motor rather than the 500W motor. If the original is a geared motor, and the new one is a DD (direct drive), then it's possible the performance would be worse on startups or even require heavy pedalling to start out with.

 

[rust]

Turn the key, nothing. Whaaaaa... Ok, key on, key off, nothing. Wiggle the power connector. Nothing. Check the LED's: on. Headlight? Working. Brake lights? Working. Crank the throttle. Nothin' honey. OK, so I hop on and pedal home to take a look.

... but I can't seem to get a reading... shouldn't I be getting (equivalent to square tooth) something like an intermittent 36V or what?

You won't get expected output from it unless it is plugged into the motor and turning it, because it operates on feedback from the halls; if it doesnt' get any it probably shuts off, if you get nothing.

Does it feel "sticky" at specific points or have a high resistance to turning when turnign the wheel by hand either forwards *or* backwards (in the case of a geared motor), while connected tot he controller but not powered on?

If so, disconnect from the controller, and see if it keeps happening.

If so, the motor probably has a short either at the repair point in the cable or inside at the phase wires, etc.

If not, the controller probably has toasted FETs.


But if you get absolutely no response from the controller to throttle, my first suspect is the connection from throttle to controller (does it get the same voltages where the wire goes to the the PCB inside it?). Sometimes wires break off isnide controllers.

Often, connections get corroded and need to be unplugged and replugged (or cleaned and then replugged). Also, crimps on contacts are often poor, and may appear to be connected but fail later, either by wire falling out or by corrosion at the wire end of the contacts.

or a problem with the battery sagging too much when you try to run the bike, even though it works before that. (probably isn't this).

Oh, and before I go, if it's the motor that's borked, can a 500W motor be put on a 250W controller without major issues?

Probably, it'll just perform like the 250W motor rather than the 500W motor. If the original is a geared motor, and the new one is a DD (direct drive), then it's possible the performance would be worse on startups or even require heavy pedalling to start out with.

It would appear it's a direct drive. This question was because of the difference in pricing on a 500W versus 200W -- which would be available in only hours as opposed to two months for a controller. For me, shipping is a killer. I can't justify 200 bucks in shipping. Or even a hundred! Not when I can get locally (within Santiago) a motor for what I would have to pay just in shipping. On the other hand, shipping for controllers is much less, so I can justify getting something direct from China for a decent price, especially these multi-voltage learning types.

Questions asked above:
Doesn't feel sticky at all in any direction.

Repair point at the cable is SUPER CLEAN. Continuity checks out from connector at the controller through to the repair point. From the repair point on inside the motor is unknown for the phase wires. The Hall wires seem ok, having checked out 0V, 5V on rotation.

The throttle checks out good at the controller connector, voltage applied at that point (5V), measured .8V at rest and 4.7 at full.

All connectors are clean and oxide free. Not a touch of copper/iron/aluminum oxide at any contact. Every connector is clean and shiny.

Visual inspection of the controller with a magnifier and a flashlight doesn't reveal any burned resistors or popped caps. Smell is pristine -- was sealed until I opened it just yesterday. Dismantling the controller from its aluminum case is problematic, but could be done.

Battery sag unlikely. Performance degradation has been noted by way of diminished autonomy, however not to the point where current application shows horrible performance. I know what the bike does (rather, what the MOTOR does) when I've hit the low end of a charge. Groooaan, groooaaan, waaaahhhh, pedal pedal pedal!

In the beginning by the way, I had been told erroneously (the locals are famous for being WRONG) that I should run down the charge completely on the battery -- as though it were Nickel-cadmium! Of course, SLA should always be topped up even after short hops. Right?

Here's a question for you: with the 3 phase connectors disconnected from the motor, power to the controller and throttle full, I should be able to measure something at the phase connectors at the controller with the wheel spinning, right? Basically I would be simulating the feedback to the controller via the Hall sensors on the spinning motor, and the controller should be providing voltage at the phase wires... voltage that would be relative to what? ground? another phase wire? that's something I'm not clear on.

Hey, thanks for the quick reply! Still wracking my noggin on this.

 

[dnmun]

you said you tested the hall sensors while disconnected from the controller. you will not see the voltage toggle when you do that so how is it that you said it did?

 

[d8veh]

Here's a question for you: with the 3 phase connectors disconnected from the motor, power to the controller and throttle full, I should be able to measure something at the phase connectors at the controller with the wheel spinning, right? Basically I would be simulating the feedback to the controller via the Hall sensors on the spinning motor, and the controller should be providing voltage at the phase wires... voltage that would be relative to what? ground? another phase wire? that's something I'm not clear on.

Hey, thanks for the quick reply! Still wracking my noggin on this.

With the motor phase wires disconnected from the controller, you get AC between each pair of phase wires when you spin the wheel.

 

[rust]

you said you tested the hall sensors while disconnected from the controller. you will not see the voltage toggle when you do that so how is it that you said it did?

Apply 5 volts on red black, measure voltage between Blue-black Green-black Yellow-black. As the wheel is rotated slowly you'll get 0V, 5V alternately and if you do it with three meters you'll see the three combos "cascading" ie 0 5 5, 5 0 5, 5 5 0 etc -- or is it 0 0 5 I forget. Spin too fast, you get a jumbled reading.

Also "the hall sensors while disconnected from the controller" should say that the PHASE WIRES are disconnected.

 

[rust]

With the motor phase wires disconnected from the controller, you get AC between each pair of phase wires when you spin the wheel.

So, at a reasonably constant velocity, I should get a reasonably stable reading on AC... And each pair should give a reasonably equal result. I need to channel Nikolai Tesla for this!

I would have thought it would be DC. I imagine the magnets are arranged alternating polarity then...

Now, if the above is true, that all three phases produce much the same AC voltage for a given rotational speed, that would mean the motor is good, right? And I should point the finger at this no-name controller.

Thanks for the input.

 

[rust]

So, at a reasonably constant velocity, I should get a reasonably stable reading on AC... And each pair should give a reasonably equal result. I need to channel Nikolai Tesla for this!

Now, if the above is true, that all three phases produce much the same AC voltage for a given rotational speed, that would mean the motor is good, right? And I should point the finger at this no-name controller.

Test results: I get a good reading of up to 12VAC on each pair doing the crank test at a moderate velocity. I had to buy some alligator clips and hang the frame from the ceiling.

I think this points to a futzy borked controller... opinions, anyone?

 

[shock]

Sounds like a bad controller to me. I like lyens controllers, high quality and he supports them. My theory is always buy more controller than you need

 

[shock]

Also, since there are no pics, don;t put the controller in a bag. Great way to overheat it. Controllers need airflow.

 

[rust]

Update: it was the controller. Bought a YK85S on eBay to replace it. After some nonsense with the thing, I got it running. Took it out today for a test ride: everything A-OK

Thanks to everyone for your guidance and suggestions