2 short weeks after QS205 and 100A controller installed, something blew

[lookinglikejesus]

Hi all,

I made 2 previous posts troubleshooting the damn bike. Finally I was able to configure a 50H QS205 V3 with a SIAECOSYS 100A controller (sabvoton clone) by passing the hall test, putting the correct parameters (245 hall angle, 16 poles, etc.) By putting it into the spare halls, I was able to get it to run optimally except for a slow takeoff where I had to go easy on the throttle, and not being able to hit it too hard lest the bike shut off. I assume this was only due to an issue of the battery I had only pulling 50A.

Well, after minimal riding in 2 short weeks, something definitely blew. Putting the key in and turning the bike on, I felt something inside the motor and it was vibrating a lot when it was in use (ie. when regen was on or through throttle, non when rolling.) It would not go fast at all (10mph roughly), with intensified vibration inside the motor. I was planning on going home to diagnose the issue, until all of a sudden the bike just shut off midride. Controller lights don't go on when ignition switch is on. Like it was completely DONE.

Not sure where even to start diagnosing the issue, if the motor was faulty/blew, the controller or possibly both. Where do I start in uncovering the source of the issue?

 

[calab]

You have to methodically go through each part. First start with the hub motor, unplug everything and see if the phases have shorted, I assume its direct drive so if the phases are shorted you will feel resistance spinning the hub. Look at the phase wiring out the axle.

After that plug in the controller and just check if there is resistance, if there is a mosfet inside the controller is bad.

Analyze how that might have happened, replace controller. Probably an expensive controller so stay sharp and investigate it, how did it happen, go over your ride, what happened.

I made 2 previous posts troubleshooting the damn bike. Finally I was able to configure a 50H QS205 V3 with a SIAECOSYS 100A controller (sabvoton clone) by passing the hall test, putting the correct parameters (245 hall angle, 16 poles, etc.) By putting it into the spare halls, I was able to get it to run optimally except for a slow takeoff where I had to go easy on the throttle, and not being able to hit it too hard lest the bike shut off. I assume this was only due to an issue of the battery I had only pulling 50A.

Well, after minimal riding in 2 short weeks, something definitely blew. Putting the key in and turning the bike on, I felt something inside the motor and it was vibrating a lot when it was in use (ie. when regen was on or through throttle, non when rolling.) It would not go fast at all (10mph roughly), with intensified vibration inside the motor. I was planning on going home to diagnose the issue, until all of a sudden the bike just shut off midride. Controller lights don't go on when ignition switch is on. Like it was completely DONE.

Not sure where even to start diagnosing the issue, if the motor was faulty/blew, the controller or possibly both. Where do I start in uncovering the source of the issue?

 

[lookinglikejesus]

ok understood, thank you. I somehow was able to get in contact with someone in possession of a few Sabvotons who also has experience with these types of bikes. My biggest worry is the motor fried or something. I'll reach back on Wednesday and update what he says. All I remember is the motor was working fine, jumped back on the bike turned the ignition on, hit the throttle and felt extremely sluggish, vibrating riding with no speed whatsoever.

 

[amberwolf]

Based on the symptoms before this problem occured, and those after, it sounds similar to when the wrong phase/hall combination is used, which often overloads the controller and motor, causing excessive heat especially at higher currents (like pushing the throttle hard suddenly, especially), and can cause vibration, shuddering, and other undesirable behavior before something actually fails.

Usually what fails is the controller, where FETs blow, but occasionally it is not a hard failure; it can even be the gate drives that partially fail, or just some FETs in a bridge, so its still "works" just not at full power.

Sometimes it's the hall sensors in the motor that fail, from repeated overheating.

Sometimes it's the wiring that fails, either the motor coil insulation from overheating, or the phase or hall wiring inside the motor cable (especially inside the axle where there is no cooling airflow).

Sometimes it is the connector that fails, where the shell or plastic mounting overheats and deforms, causing high-resistance connection.


Some of these are easy to visually check, and some require a multimeter to test. Some require opening things up to verify; some don't. Ebikes.ca - learn - troubleshooting has some good test documentation you can check out.

 

[lookinglikejesus]

Appreciate the advice, I'll check out the link. Starting out with the lowest hanging fruit, the battery connector. Voltage is correct, 80.3V on the actual discharge connector as well as battery + and - on the controller. Light just doesn't come on, might change the connector and see if that does anything and work from there.
EDIT: not the connectors.

 

[lookinglikejesus]

So I've purchased the "ebike tester" device ready to test out the hall and phase connections on both the motor and controller. Controller might be a complete dud, motor will be interesting. Only thing is, the connectors on both are different, with the tester having the standard 6 pin and the QS/Sabvoton both having what's called a DJ7061Y 6 pin connector which is hard to come by. Guessing I will need to create some kind of an adapter so I can connect both?

 

[DogDipstick]

Hi all,

I made 2 previous posts troubleshooting the damn bike. Finally I was able to configure a 50H QS205 V3 with a SIAECOSYS 100A controller (sabvoton clone) by passing the hall test, putting the correct parameters (245 hall angle, 16 poles, etc.) By putting it into the spare halls, I was able to get it to run optimally except for a slow takeoff where I had to go easy on the throttle, and not being able to hit it too hard lest the bike shut off. I assume this was only due to an issue of the battery I had only pulling 50A.

Well, after minim...

I thought the QS V3 50H motor has 16 pole PAIRS, not " 16 poles". ... I dont know if it would matter.




"Pole pairs" is not the number of coils in the motor. The # of pole pairs is equal to the # of magnets divided by 2, assuming each magnet has a single pole facing towards the air gap arranged in a N S N S .... sequence around the rotor. Most BLDC motors use a stator having a # of coils different from the # of poles or pole pairs. " - major

 

[lookinglikejesus]

Honestly not sure, ebikes are certainly not my expertise. All I recall is to put 16 in that category because the QS 205 has 16 pole pairs.

Anyway, update. So I was able to connect the tester to the device into the motor by simply sticking ends to the back of the 6 pin connector of the hall sensor connector (DJ7061Y that I can't find locally and would take weeks to ship) and just making sure the colors match. Phase were just alligator clips.

Looks like the halls are totally fine, because all the lights for the halls go off on a sequential order. For the phase test, not sure how it's supposed to go but faint lights go off every rotation or so for those lights. I have video of it.

So would that mean the hall sequence is bad, or the fault would've been on the controller end?

 

[lookinglikejesus]

Latest update: Got it working by using a cheap, $30 controller from Ebay that runs with and without halls. Actually running it with halls too. The motor is working perfect, seems like the controller was the bad part the whole time.