QS 205 main hall connector fails test, spare one passes?

Joined
Mar 14, 2022
Messages
26
Hi,

so recently the positive end of discharge connector on my pack tore and that damaged my controller, which I will replace. I have the ebike tester device (the generic chinese one) and it showed that the coils on the motor are fine, but the halls for the main hall sensor showed two lights stuck and one frozen upon spinning the wheel, indicating bad halls. However, when I plugged the tester into the spare set, the halls were shown to work perfectly.

So what exactly does this entail? From what I understand, there's only one set of halls, and the spare acts as a backup. What exactly is damaged, the harness? The wire? What's the process of replacing it, if there is any, and can I ride with the spare for now?
 
Are you wanting to just use the spare set? If so, you can just do that, the same way you plugged the tester into them, but using the controller instead.

Are you wanting to repair the other set? If so, you would need to open the motor, which usually requires a 3-jaw puller to do easily and safely; there are a number of threads around the forum that show and/or describe disassembling a motor for various kinds of repairs. There are a few that also show the internals of the QS205, including some of my posts from a couple of years back or so, probalby in my SB Cruiser thread. (not sure if I showed the disassembly process itself for those, but earlier posts about an MXUS 450x motor do, as do various earlier posts about earlier motors in the SBC and the CrazyBike2 threads, etc).

Then you'd replace the specific hall sensor(s) that are not working, usually with p/n SS41 or SS411 (latching bipolar open-collector).

Unless you had axle wire damage (such as from a crash, or the axle spinning out in the dropouts, etc, for a hubmotor) or other physical wire damage (again usually caused by externally-caused damage to the cable), it's unlikley to be a wiring issue.

To get cable damage from an electrical problem, it would usually mean such high currents flowed thru phase wires that they melted insulation on themselves and then on any other wires in the motor cable that were touching them; this usually results in shorting phases together and making the motor very hard to turn by hand. If phase and hall wires were shorted together in the process, then battery voltage (switched by controller to feed to motor phases) gets applied to the halls and controller, and usually damages or destroys them, and anything else connected to them (like a speedometer or Cycle Analyst using a motor hall for speed sensing). From the description of the failure you had, it's unlikely that any of that has happened.


BTW, "two lights stuck and one frozen" sounds like all three are "stuck" or "frozen", because those essentially mean the same thing--not changing state (always on or always off). If you mean something else, you'll need to restate it more clearly / specifically for the exact results you get on the test.




lookinglikejesus said:
so recently the positive end of discharge connector on my pack tore and that damaged my controller, which I will replace. I have the ebike tester device (the generic chinese one) and it showed that the coils on the motor are fine, but the halls for the main hall sensor showed two lights stuck and one frozen upon spinning the wheel, indicating bad halls. However, when I plugged the tester into the spare set, the halls were shown to work perfectly.

So what exactly does this entail? From what I understand, there's only one set of halls, and the spare acts as a backup. What exactly is damaged, the harness? The wire? What's the process of replacing it, if there is any, and can I ride with the spare for now?
 
appreciate the response, Im mostly trying to understand what happened. So yes, what I mean by the lights "stuck" and "frozen" is, yes they are not changing state at all. Two of them are always on, one of them is off. However, for the spare hall this isn't the case. All of them work.

It is possible it is a wiring issue, all I know is when I came over to the bike, it wouldn't work, and upon further investigation the positive end of the discharge wire was torn from the cell side. I resoldered that.

So from what I understand, the two sets of hall harnesses go to the same hall sensors right? Or is there two seperate sets of halls and each connector goes to a different one respectively?

Also, apparently the controller does still work. It's just from the tester the light doesn't come on.
 
lookinglikejesus said:
So from what I understand, the two sets of hall harnesses go to the same hall sensors right? Or is there two seperate sets of halls and each connector goes to a different one respectively?
Two completely independent sets. AFAICR on mine even the power and ground are independently wired.
 
amberwolf said:
lookinglikejesus said:
So from what I understand, the two sets of hall harnesses go to the same hall sensors right? Or is there two seperate sets of halls and each connector goes to a different one respectively?
Two completely independent sets. AFAICR on mine even the power and ground are independently wired.

Ah okay, didn't know that.

So the controller is still fine, by the way. I'm running it hallless mode, in fact I can't even tell a difference without the hall sensors plugged in. The ebike tester doesn't show the 5V controller light come on, but the controller still works so not sure what that entails. I didn't have any real components on it like a display or anything etc. for it to have been a short issue. All I know is that the positive end was pulled off the discharge end of the battery, I resoldered that and battery works. Could it be just something inside the hall harness is just not in correctly?
 
lookinglikejesus said:
So the controller is still fine, by the way. I'm running it hallless mode, in fact I can't even tell a difference without the hall sensors plugged in.
If there's no difference in operation at all, then it is easily possible that the halls have never actually worked.

Normally without halls, there is some extra noise, vibration, etc., when starting up from a stop under load. With halls, this is usually less or nonexistent.

Is your system completely silent regardless of conditions?



The ebike tester doesn't show the 5V controller light come on, but the controller still works so not sure what that entails.

I don't know how the original problem you had, of the battery pack's discharge wiring tearing, could cause the 5v for the halls to fail, without also causing the 5v for everything else to fail, because there is only one 5v source in the controller.

The only difference between the hall 5v and all the other 5v wires out of the controller is that often a diode is placed between the 5v source and the pad the hall 5v is wired to inside the controller, so that the 5v source is protected in the event of a phase wire shorting to the hall 5v wire when motor cable damage happens. (though it doesn't protect against the hall *signals* being shorted to phase wires; when that happens it can kill the MCU as well as the halls).

But if you didn't have any motor cable damage, then there should be no way to short the hall 5v wire to anything else, and so there should be no damage to the halls nor to the controller's hall 5v output.




Could it be just something inside the hall harness is just not in correctly?

I'm not sure what you mean by that, but if you think there is a wiring issue you would need to physically examine and then electrically test each wire all the way from inside the controller to inside the motor, including the connections between the two.
 
Now that you mention it, it's always been kind of noisy. I do know that I've used the tester on it, for this set of halls and the halls were shown to work perfectly.

One thing to note is that, I had to make "converter" type connector to connect the controller and the motor's halls. The motor has like a strange 6 pin connector suited for a car, and the controller has the standard 6 pin. I don't know the names but I could show a picture, so basically I created a connector that would go to each respective color, the 3 hall wires, positive and ground. I mention that because you said there should be no way to short hall 5v to other things or itself.

I'll definitely inspect the wires physically. Is it safe to depin them and physically touch them? I remember the QS205 guide said something about your hands transmitting way more than 5V and not to actually touch those hall wires, but I do remember people also talked about finding the right hall combination in cases where the were not shipped correct. Aside from there being a physical issue, it could be something shorted those halls, or possibly the halls never working correctly. I just know that just a few short months ago the ebike tester showed the halls were perfect.
 
When no power is applied (battery disconnected from system) it should be perfectly safe to handle whichever parts or wires you need to, as long as you observe proper ESD precautions. ESD is electrostatic discharge, and can be thousands to millions of volts (the latter in lightning, etc, rather than from human-body sources). It may not actually destroy parts, but instead just damage them in a way that makes them unreliable. :(

A tested ESD-protective wrist or ankle strap, properly grounded and properly fitted to you, is the most certain easy way to prevent such damage, but in a pinch you can just touch a known-well-grounded surface prior to handling the wiring, as long as you're not wearing clothing you know generates a lot of static electricity, and/or it's not really dry weather, etc. If you touch things and get zapped from static, you should probably use the grounded ESD strap to prevent static build up on you that will then discharge into the electronics instead.

(since it's fairly likely that none have been used on any of these parts during manufacture of the motor, then it's not all that likely you'll do any more damage than has already been done, even if you don't use any...though it doesn't mean you won't damage anything.)



lookinglikejesus said:
Now that you mention it, it's always been kind of noisy. I do know that I've used the tester on it, for this set of halls and the halls were shown to work perfectly.

One thing to note is that, I had to make "converter" type connector to connect the controller and the motor's halls. The motor has like a strange 6 pin connector suited for a car, and the controller has the standard 6 pin. I don't know the names but I could show a picture, so basically I created a connector that would go to each respective color, the 3 hall wires, positive and ground. I mention that because you said there should be no way to short hall 5v to other things or itself.

I'll definitely inspect the wires physically. Is it safe to depin them and physically touch them? I remember the QS205 guide said something about your hands transmitting way more than 5V and not to actually touch those hall wires, but I do remember people also talked about finding the right hall combination in cases where the were not shipped correct. Aside from there being a physical issue, it could be something shorted those halls, or possibly the halls never working correctly. I just know that just a few short months ago the ebike tester showed the halls were perfect.
 
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