Troubleshooting hub motor

General Discussion about electric bicycles.
Post Reply
Butch1   1 mW

1 mW
Posts: 15
Joined: May 26 2018 4:01pm

Troubleshooting hub motor

Post by Butch1 » Jan 26 2020 4:03pm

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.

User avatar
motomech   1 GW

1 GW
Posts: 3383
Joined: Sep 11 2010 12:21am
Location: Punta Cana Baja Mexico

Re: Troubleshooting hub motor

Post by motomech » Jan 26 2020 10:30pm

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.
Motomech

'03 Rocky Mountain Edge 2WD 260 Q100H frt and Ezee V1 rear 2 Elifebike 20A & 25A 9-FET controllers 12S/10Ah Multistar Lipo rear 4Ah Turnigy frt Luna Cyclops Extra lite Alex 24DM rims, Crazy Bobs run ghetto tubeless. 25 mph. Mean Well HLG-320H-54A
https://endless-sphere.com/forums/viewt ... =3&t=83430
'07 GT Idive 4 4.0, Q100C 201 14S LiPoly elifebike 9-FET 20A controller. 23 MPH.
https://endless-sphere.com/forums/viewt ... 4#p1378484

Butch1   1 mW

1 mW
Posts: 15
Joined: May 26 2018 4:01pm

Re: Troubleshooting hub motor

Post by Butch1 » Jan 26 2020 10:52pm

motomech wrote:
Jan 26 2020 10:30pm
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.
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.

markz   100 GW

100 GW
Posts: 8610
Joined: Jan 09 2014 11:38pm
Location: Alberta Canada

Re: Troubleshooting hub motor

Post by markz » Jan 26 2020 11:48pm

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.

User avatar
motomech   1 GW

1 GW
Posts: 3383
Joined: Sep 11 2010 12:21am
Location: Punta Cana Baja Mexico

Re: Troubleshooting hub motor

Post by motomech » Jan 27 2020 12:00am

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:)
Motomech

'03 Rocky Mountain Edge 2WD 260 Q100H frt and Ezee V1 rear 2 Elifebike 20A & 25A 9-FET controllers 12S/10Ah Multistar Lipo rear 4Ah Turnigy frt Luna Cyclops Extra lite Alex 24DM rims, Crazy Bobs run ghetto tubeless. 25 mph. Mean Well HLG-320H-54A
https://endless-sphere.com/forums/viewt ... =3&t=83430
'07 GT Idive 4 4.0, Q100C 201 14S LiPoly elifebike 9-FET 20A controller. 23 MPH.
https://endless-sphere.com/forums/viewt ... 4#p1378484

User avatar
amberwolf   100 GW

100 GW
Posts: 29087
Joined: Aug 17 2009 6:43am
Location: Phoenix, AZ, USA, Earth, Sol, Local Bubble, Orion Arm, Milky Way, Local Group
Contact:

Re: Troubleshooting hub motor

Post by amberwolf » Jan 27 2020 12:46am

Butch1 wrote:
Jan 26 2020 4:03pm
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.
the most common causes of sudden system stoppage are battery failure and wiring problems.

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?

Butch1   1 mW

1 mW
Posts: 15
Joined: May 26 2018 4:01pm

Re: Troubleshooting hub motor

Post by Butch1 » Jan 27 2020 2:41am

amberwolf wrote:
Jan 27 2020 12:46am
Butch1 wrote:
Jan 26 2020 4:03pm
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.
the most common causes of sudden system stoppage are battery failure and wiring problems.

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.

OK, I was riding along and hit a few rough bumps/potholes, bike kept going fine for another 2-300Ft or so then shuddered a few seconds and quit. Usually this meant the battery connection got rocked loose but I never lost power to the console at all so I know power if flowing to the controller since the LED console gets it's power from there. Pedaled home and started looking at the 3 phase wiring to the motor, (it has no hall's) everything looked intact. Checked wiring from PAS, brake levers, nothing looked out of place or chafed, I think it's possible I might have upset the controller with the bumps, it is 5ys old at least, low power setup though so a 250 watt motor doesn't ask for a lot current-wise. I'll find out more tomorrow with a visual inspection of the controller and will post back, thanks for responding.

next:
by the various parts being "fine", what exactly was tested, and how?

User avatar
dogman dan   100 GW

100 GW
Posts: 35418
Joined: May 17 2008 12:53pm
Location: Las Cruces New Mexico USA

Re: Troubleshooting hub motor

Post by dogman dan » Jan 27 2020 8:15am

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.

Butch1   1 mW

1 mW
Posts: 15
Joined: May 26 2018 4:01pm

Re: Troubleshooting hub motor

Post by Butch1 » Feb 08 2020 5:36pm

dogman dan wrote:
Jan 27 2020 8:15am
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.
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.

markz   100 GW

100 GW
Posts: 8610
Joined: Jan 09 2014 11:38pm
Location: Alberta Canada

Re: Troubleshooting hub motor

Post by markz » Feb 08 2020 7:30pm

Not sure if any ole mosfet will do, they might have to be somewhat in the "ballpark"..... "matched" but its worth a try.

Butch1   1 mW

1 mW
Posts: 15
Joined: May 26 2018 4:01pm

Re: Troubleshooting hub motor

Post by Butch1 » Feb 08 2020 7:53pm

markz wrote:
Feb 08 2020 7:30pm
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.

Voltron   10 MW

10 MW
Posts: 2172
Joined: May 02 2013 4:53pm
Location: Santa Barbara CA

Re: Troubleshooting hub motor

Post by Voltron » Feb 09 2020 8:41am

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.

Butch1   1 mW

1 mW
Posts: 15
Joined: May 26 2018 4:01pm

Re: Troubleshooting hub motor

Post by Butch1 » Feb 09 2020 10:49am

Voltron wrote:
Feb 09 2020 8:41am
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   10 MW

10 MW
Posts: 2172
Joined: May 02 2013 4:53pm
Location: Santa Barbara CA

Re: Troubleshooting hub motor

Post by Voltron » Feb 09 2020 12:41pm

It works with a gear motor also, as long as you spin it forwards.

Butch1   1 mW

1 mW
Posts: 15
Joined: May 26 2018 4:01pm

Re: Troubleshooting hub motor

Post by Butch1 » Feb 09 2020 3:01pm

Voltron wrote:
Feb 09 2020 12:41pm
It works with a gear motor also, as long as you spin it forwards.
With a gear hub if it's spinning forward, (while not under power), it freewheels on the planetary gear set. I might try it out just for shits and giggles though.

Voltron   10 MW

10 MW
Posts: 2172
Joined: May 02 2013 4:53pm
Location: Santa Barbara CA

Re: Troubleshooting hub motor

Post by Voltron » Feb 09 2020 6:15pm

My bad..I meant backwards so the clutch is engaged..

Butch1   1 mW

1 mW
Posts: 15
Joined: May 26 2018 4:01pm

Re: Troubleshooting hub motor

Post by Butch1 » Feb 15 2020 7:50pm

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 GW

100 GW
Posts: 8610
Joined: Jan 09 2014 11:38pm
Location: Alberta Canada

Re: Troubleshooting hub motor

Post by markz » Feb 15 2020 11:17pm

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 wrote:
Feb 15 2020 7:50pm
damm I missed my bike!.

Butch1   1 mW

1 mW
Posts: 15
Joined: May 26 2018 4:01pm

Re: Troubleshooting hub motor

Post by Butch1 » Feb 15 2020 11:44pm

markz wrote:
Feb 15 2020 11:17pm
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 wrote:
Feb 15 2020 7:50pm
damm I missed my bike!.
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   100 GW

100 GW
Posts: 8610
Joined: Jan 09 2014 11:38pm
Location: Alberta Canada

Re: Troubleshooting hub motor

Post by markz » Feb 17 2020 1:15pm

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.

Butch1   1 mW

1 mW
Posts: 15
Joined: May 26 2018 4:01pm

Re: Troubleshooting hub motor

Post by Butch1 » Feb 17 2020 5:59pm

markz wrote:
Feb 17 2020 1:15pm
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.
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!.

Post Reply