48V dd hub on 36V bike?

[JayS]

Hi,

Bought an ebike (not going) to learn something about ebikes.
Batt is good 52.3V; batt meter on the handlebar reads full; no response from throttle.

Tested the controller as per-
viewtopic.php?f=2&t=52871&p=786074&hilit=logic+supply+is+good#p786074
and found 0V at the red and black wires on the Hall and throttle plugs - so the controller logic is fried, I think.

There is wheel resistance with shorted phase wires.

I opened the controller and resoldered a few dodgy looking joints, just in case, but no luck.

Looks to be a Trotter kit.

Can I connect my 48V 1500W dd hub to a 36V 10A (gear hub) bike to see if the 48v hub turns?

Thank You for your advice,

Cheers,
Jay

 

[dogman dan]

Don't do that just yet. Don't risk a good controller just yet. You can test the motor in other safer ways. Since the wire order of one motor is likely different from another, you'd have to test a lot of combinations to prove anything, wasting a ton of time.

Does the resistance to turning the motor wheel go away if you unplug the controller? If so , it's likely the controller blew a fet. That causes a short, which increases the resistance to turning the motor.

If the resistance persists, and none of the big phase wires are touching each other, then the short is in the motor itself. If the phases are shorted, try to find a flaw in the wiring. It could be inside the axle, from melted insulation. Fried windings are fairly obvious, really black and stinking.

Testing the halls in the motor is fairly simple. 4-5v power to the red and black wires. Turn the motor while looking at a voltmeter, or even just a 6v test light bulb. That tester is connected to the red, and one of the b g or y wires.

Look for the voltage to turn on and off as you rotate the wheel, or turn the axle with a wrench.

That gets you through testing the motor itself.

 

[JayS]

There is wheel resistance with shorted phase wires.

Sorry, that shouldn't've been included in the post.

With all of the hub wires disconnected from the controller, I shorted two phase wires at a time; Y/B, Y/G & B/G, and felt resistance to the hub turning each time. At all other times, there is no resistance.

Grin Tech: Testing for Blown Mosfets - FET's tested ok.

With everything connected and ignition ON, there is 0V at the Hall and throttle plugs.

Should I disconnect the Hall/Phase ccts and connect a 5V external source to test the Hall sensors?

 

[dogman dan]

I would. Now you know the phases and wires are ok. Next will be trying to find the right colors to run with a different controller.

I would not want to try that without knowing for sure that you have good halls in the motor.

The controller should be fixable, if you are smarter than I. I'm pretty much, it's broken get another kind of guy. I can't understand explanations of how to fix the black box at all.

Sounds like the whatever it is that converts your pack voltage to 5v for the halls and throttle went.

 

[Drunkskunk]

It would help to know what controller you have. Pics would be a bigger help.

Since you mentioned switching on the ignition, the first place I would look is that switch. High voltage DC and switches don't play nice, so any switch on an ebike is suspect. it may just be a bad switch.

 

[dogman dan]

Yep, investigate all switches and all plugs before you dump the controller. That's always step one of a troubleshoot. 90% of the time, a plug is the culprit.

 

[aroundqube]

Door lock wire could get to be an inside joke around here. Anyway, the battery in the picture mounted on the bike could have an inline fuse. Look for a cap that unscrews on the battery,covering a fuse holder.

 

[JayS]

trying to find the right colors to run with a different controller

I've started reading about this.

Sounds like the whatever it is that converts your pack voltage to 5v for the halls and throttle went

I'll see if I can trace it back.
==========

Pics would be a bigger help

I uploaded pics - aren't they viewable?

it may just be a bad switch

The battery display on the handlebars show full battery and there is 53V at the display plug.
==========

inline fuse

Yes, I read a thread about the door lock wire, mine is hard wired to the controller plug. The inline fuse is ok (batt to display meter).
==========
Awesome help, Thanks!

I'll read up on the hub motor construction and how to test run a hub.
I'll see if I can restore the 5V to the Hall/Throttle plugs.
Ebike tester is on it's way but may take a while.
I couldn't buy one bike, I had to have two (for testing etc) - just didn't realise they came in different voltages that's how much I knew about ebikes one week ago

Cheers

 

[dogman dan]

Super good pic of the inside of that controller, then one of the resident geniuses can point out which bit inside is the resistor that likely burnt, that powers up the low voltage part of the controller.