Hello all, my setup is a Bafang 250 watt rear hub with no hall sensors, bike just quit, battery is fine, battery connections are fine, brake cutoff's are fine, wiring looks OK. So I'm left with controller/hub, is it possible to test the 3 hub phase winding's with a multimeter or must I get the $30 testing device?, Thanks in advance, Barry.
-
Howdy! we're looking for donations to finish custom knowledgebase software for this forum. Please see our Funding drive thread
Troubleshooting hub motor
- Thread starter Butch1
- Start date
motomech
10 MW
I think you are at the point where taking apart and seeing what has melted would be the best plan.
I'm not sure how one would test if the winding are be energized, w/ any kind of tester. But then again, all my problems are w/ halls, melted phase wires or controllers, so maybe there is.
On controllers, the best way to test them is to keep at least two.
Maybe you can get another motor cheap and just swap out the cores.
I'm not sure how one would test if the winding are be energized, w/ any kind of tester. But then again, all my problems are w/ halls, melted phase wires or controllers, so maybe there is.
On controllers, the best way to test them is to keep at least two.
Maybe you can get another motor cheap and just swap out the cores.
Yea, I'm off tomorrow so I plan on taking the controller off the bike and testing the mosfet's and checking out the caps as well. It's integrated into a plastic housing where the rack meets the frame, hopefully it's that and not the motor, it did a bit of shuddering for a few seconds before it croaked and it's been in service for 5+ years, the last 3 almost a daily driver. Most of the replacement controllers i see are using the hall's, it's unclear to me if they would run without sensor input.motomech said:
markz
100 TW
Thats why its best to always have spares.
Buy two sensorless controllers from Greentime and call her a day.
Meanwhile open up the controller and sniff it :lol: then look for any black marks.
Then crack open the motors cover plates, do another sniff test and eyeball the mofo.
Buy two sensorless controllers from Greentime and call her a day.
Meanwhile open up the controller and sniff it :lol: then look for any black marks.
Then crack open the motors cover plates, do another sniff test and eyeball the mofo.
motomech
10 MW
Yeah, I could fill a milk crate w/ dead controllers.
Unless they are something special, they aren't worth messing with.
The stuff I use is cheap (maybe not so much w/ freight), just waiting sucks. That's why I stock extras, plus trying to consolidate shipping costs.
I can't believe you went 5 YEARS w/ out smoking something.
Now order two of everything
Unless they are something special, they aren't worth messing with.
The stuff I use is cheap (maybe not so much w/ freight), just waiting sucks. That's why I stock extras, plus trying to consolidate shipping costs.
I can't believe you went 5 YEARS w/ out smoking something.
Now order two of everything
the most common causes of sudden system stoppage are battery failure and wiring problems.Butch1 said:
since there's a lot of possibilities, then before we can really help, we'll need some clarification.
what specifically does "bike just quit" mean?
did all power fail, meaning that all lights, screens, etc., turned off, as well as the motor stop working?
or did lights/screns/etc stay on, while the motor stopped?
the former indicates a problem with power, either the battery not providing power to the system, or the controller no longer being kept on with it's ksi "keyswitch / ignition" input from display, switch, etc.
the latter indicates a problem with many more possible sources, depending on the exact symptoms and the resutls of various tests we can point you to once we have more details.
next:
by the various parts being "fine", what exactly was tested, and how?
dogman dan
1 PW
Testing motors is pretty easy, to do a basic check. Roll the wheel backwards, if it resists a LOT, you have melted and shorted phase wires, or the winding itself.
Checking halls is easy with a voltmeter, and a 4v cell. Hook the cell to the red and black to power up the halls. See if they toggle on and off, with the voltmeter on the black wire, and the red lead on g b or yellow wire. If they stay off, or on, halls cooked off.
But 95% of the time, its something in the wiring. Look again, look hard.
Checking halls is easy with a voltmeter, and a 4v cell. Hook the cell to the red and black to power up the halls. See if they toggle on and off, with the voltmeter on the black wire, and the red lead on g b or yellow wire. If they stay off, or on, halls cooked off.
But 95% of the time, its something in the wiring. Look again, look hard.
Well, finally got around to some serious testing today, one of the Mosfet's has failed, by using this vid from Grin as a guide,https://www.youtube.com/watch?v=lTssCn5YyTw one of the three phases has shorted directly to V+. Although these type of 350 watt controllers are cheap I've decided to try and repair this one, I've got the soldering skill to do so and replacement Mosfet's are dirt cheap. The reason being is finding a replacement controller that has pedal assist and works without Hall sensors, then the connectors will probably be different so a lot of cutting/soldering there as well and the LED dash unit will not work with a new controller either. I have several old computer power supplies lying around, it's possible I might be able to harvest a Mosfet from one of them. Thanks to all who replied, I'll keep you guys informed on how it goes.dogman dan said:
markz
100 TW
Not sure if any ole mosfet will do, they might have to be somewhat in the "ballpark"..... "matched" but its worth a try.
Your correct, I looked at some from the computer PS's I had lying around, those were around 500 volt 8 amp range but the one from the controller came back as 70 volt 75 amp. They are only $1.50/ea at Mouser, probably better quality than what it was originally built with, I might just change out all 6, from where the controller is mounted it's a bit of a pain to take it all apart.markz said:
Voltron
1 MW
A quick field test is to short two of the three phase wires together and hand spin the motor. The motor starts cogging when the windings aren't damaged... If the motor still spins freely the winding are damaged internally.
I don't know if that would work with a geared motor or not, luckily, it seems to be a controller issue. With the way it's stuffed into a clamshell plastic housing behind the seat airflow is all but impossible so I'm surprised it lasted 5 years. The bike saves me considerable $$ in gas and wear and tear on my 14 yr old car, those short 1-3 miles trips are horrible for a car.Voltron said:
Voltron
1 MW
It works with a gear motor also, as long as you spin it forwards.
Voltron
1 MW
My bad..I meant backwards so the clutch is engaged..
Update.........SUCCESS!!!!!! installed replacement Mosfet from Ebay, (5 for $5.50) and she fired right up!. Now as we know these 250-350 watt controllers are dirt cheap but for someone sporting a 1000W model they can be sporting 12 Mosfet's and are not that cheap. Now to assemble everything and take her for a test ride, damm I missed my bike!.
markz
100 TW
I know what you mean. Sometimes I panic when something breaks down, then I feel bummed out if the ebikes down for a day, even one night. Riding today, having more then 1 gear, its a gravy train, a dream cloud riding a half decently powered ebike even if it be only 36V 35A, the hills dont bother me even though I still want to pedal to save juice.
Butch1 said:
Most of the time I use it for quick errands like coffee or eggs, I only live about 3 miles from the most distant store and here in FL it's flat as a pancake, even a 250W Bafang does just fine. I do, at times, think about upping power, I know a Bafang can take more than 250W, (in short blasts and not uphill) but the 48V battery is still too expensive IMO.markz said:
markz
100 TW
In a big city like Calgary Alberta with a population of 1.35M
I have everything I need within 4-5km (2-3 miles). 2 Walmarts, 5 large grocery stores, countless fast food joints and restaurants, coffee joints, banks, conv stores. I could not go outside 4-5km for years and years, but I still constantly go to the other side of town (35km) just because I can.
I like to cruise around aimlessly, was like that even when I had a vehicle.
I have everything I need within 4-5km (2-3 miles). 2 Walmarts, 5 large grocery stores, countless fast food joints and restaurants, coffee joints, banks, conv stores. I could not go outside 4-5km for years and years, but I still constantly go to the other side of town (35km) just because I can.
I like to cruise around aimlessly, was like that even when I had a vehicle.
Yea, riding the bike, (to me) is fun, driving my car is not, (except when it's raining!). You also see a lot more, about a month ago I spotted a huge 70" TV box in the trash, behind it was a 60" TV, no cracked screen or anything so I went home and got my hand dolly and brought it home. A $25 power supply board fixed her right up and now I have an official "big" screen!.markz said:
Similar threads
