motor/controller issue.

[dan.bates]

Hello,

I have a faulty rear hub motor, geared, brushless.

Bought from Saili Motor Co. Ltd..

Seems water damage cause the SW900 display to pop, I replaced it and the display comes back up. However there's a funny thing going on with the motor now.

When I press the throttle the motor runs for a second, and then is cut. I can keep doing this and it keeps cutting.

I opened the motor and there was a powder of either aluminium from corrosion or magnets scraping against the side, not sure.

Is there any diagnosis I can do to work out what's wrong? Any settings relevant on the SW900 to make it work? Shall I buy a new controller and if so which controller will work with the sw900 display?

Thanks in advance.

Dan

 

[Andy-Mat]

Hello,

I have a faulty rear hub motor, geared, brushless.

Bought from Saili Motor Co. Ltd..

Seems water damage cause the SW900 display to pop, I replaced it and the display comes back up. However there's a funny thing going on with the motor now.

When I press the throttle the motor runs for a second, and then is cut. I can keep doing this and it keeps cutting.

I opened the motor and there was a powder of either aluminium from corrosion or magnets scraping against the side, not sure.

Is there any diagnosis I can do to work out what's wrong? Any settings relevant on the SW900 to make it work? Shall I buy a new controller and if so which controller will work with the sw900 display?

Thanks in advance.

Dan

View attachment 34593

Some people buy and e-bike tester, which are available on ebay for under 10 UK Pounds.
Get one with the "circle" of LEDs display, as shown on the first video.
Some only have a "line of LEDs", which make understanding of the motor action less easy to follow I feel....
It tests the outputs of the controller going to the motor, the motor windings and the Hall effect sensors.
I even know of a bike shop, with fully qualified mechanics, who use one as it is apparently far faster in use than using a Meter, which requires a lot of technical knowledge to interpret the readings!
These units interpret the results for you!
These videos will give you some ideas:-

Best of luck
Andy
PS. I almost forgot, you should not have any metal filings in a motor, that is really "bad" to say the least!!

 

[dan.bates]

That's super helpful thanks. Yes they're cheap on ebay.

Do you know what Q4 is on my board? Sorry the blur is terrible, it's the component with three leads coming back towards the middle from the PCB and a white plastic spacer.. guessing temperature sensor but not sure.

The first video was very informative, shows the halls have a digital output, indicating also when the wheel was stationary. So I've managed to test my halls with a probe quite easily knowing they're digital.

Dreading to consider having to rewire in a new controller. Damned if I'm able to get one with the same connectors.

 

[Andy-Mat]

That's super helpful thanks. Yes they're cheap on ebay.

Do you know what Q4 is on my board? Sorry the blur is terrible, it's the component with three leads coming back towards the middle from the PCB and a white plastic spacer.. guessing temperature sensor but not sure.

The first video was very informative, shows the halls have a digital output, indicating also when the wheel was stationary. So I've managed to test my halls with a probe quite easily knowing they're digital.

Dreading to consider having to rewire in a new controller. Damned if I'm able to get one with the same connectors.

I understand your worries on that point, as Chinese firms are not always using the same wire colours, or the same connectors either, but the connectors are all available on ebay.
Furthermore, I am sure that someone here can help you better than I can, once you have identified where your own bike has problems. That needs to be done first. So do you know if you have a motor problem or a controller/LCD problem? That is where the e-bike tester can be very very helpful, as it can test several signals at the same time, difficult with just one meter.
But it's very good that you know how to use a meter, as that will also save you a lot of difficult detective work.
Controllers and LCD displays can be bought cheaply on ebay, ones with throttle and PAS and other needed features, from memory, from about 30 UK pounds upwards. Sadly, often with poor information, so make sure that the seller is able to supply full information about the units, wire colour code and signal names, before buying....
Have you measured your battery voltage yet when fully charged? Post it 's value here, and the "nominal" voltage that it has. Thats a good place to start, as battery and charger problems, are a large part of e-bike problems.
regards and best wishes
Andy

 

[wheeliepete]

Do you know what Q4 is on my board?

It's a speed sensor.

 

[dan.bates]

It's a speed sensor.

Excellent, the 'speed measuring magnet' setting on the display has become slightly less confusing..



found the magnet.
Wondering now if this sensor is critical to the function of the controller...
...tried testing it, bending the sensor closer to the magnet, no luck there. I'll be opening the controller next for any obvious faults.

Will probably just end up buying a controller, making sure it works with sw900 display and throttle..
Thank you both.