And that’s why I though it was a soldering issue at first…
board is still running well, i finally charged my 14s lifepo4 battery to 3.65/cell (51.1V), and was getting some braking issues.
It was cutting out, so I would let off the brake, then back on, and that usually brought them back.
looks like I was throwing a bunch of over voltage, and a couple over abs current, codes:
The following faults were registered since start:
Fault : FAULT_CODE_OVER_VOLTAGE
Motor : 1
Current : -11.4
Current filtered : -9.6
Voltage : 57.14
Duty : 0.014
RPM : 2083.4
Tacho : 553775
Cycles running : 45172
TIM duty : 116
TIM val samp : 4200
TIM current samp : 4200
TIM top : 8400
Comm step : 0
Temperature : 36.29
Fault : FAULT_CODE_ABS_OVER_CURRENT
Motor : 1
Current : -10.6
Current filtered : 48.9
Voltage : 39.74
Duty : 0.512
RPM : 25431.2
Tacho : 1160140
Cycles running : 92970
TIM duty : 4299
TIM val samp : 4200
TIM current samp : 4200
TIM top : 8400
Comm step : 0
Temperature : 35.00
I guess it seems like the board was protecting itself, which is great, but I’m wondering why it was seeing such high voltages, and why it reported abs_over_curr when it was only 48.9A
motor: 60,-60,90
battery: 27,-7
3 Likes
I just opened a quality complaint through JLCPCB’s order page menu.
What are the chances we will receive the refunds?
I have just looked at by DRV batch, it is 88ASYCTG4. So on my side, 8 good (at least for now as I remaining components are still on the way), 2 are bad. However, I am just a bit worried that even though DRVs seems good now, are they capable of delivering intended performance? It would sad to throw 200€ out of the window.
Also, as I a not EE, I had discussions with some good ones and they also were interested in some PCB design decisions of FOCer 2, especially thermal reliefs as based on their opinion, these might lead to poor soldering during SMT process. Results also might highly depend on position of your PCBs on the conveyor (if you are lucky to be somewhere in the middle). If that is the case, there still might be some poorly soldered contacts that can deteriorate overtime. @shaman What is your experience regarding this? Do you think it is possible to have some hidden potential problems?
Thanks! and really appreciate the work you have done!
1 Like
They offered me to refund 25 DRV chips.
Just to clarify, when testing your DRVs with the diode tester method you need to use one that does 3V. Otherwise this test is useless.
Good
NEG - POS + 2.615
NEG + POS - 0.555
BAD
NEG - POS + >3V
NEG + POS - 0.576
Also the 0.55V measurements are just for reference, only a 2.6V measurement means a good DRV.
7 Likes
Did they offered to refund just DRV or entire boards?
Just the DRV 
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Basterds.
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Offering a refund for the DRV chips is not enough, for me the DRV killed other components on the PCB that needs replacement. Who knows what other components will fail over time due to this?
Regardless, people who purchased the FOCer with no access to a reflow station will gain no benefits from a refund/replacement for the DRV.
to JLCPCB.
Yeah you are right. They recommend not to use the DRV chip and its not even a refund, they offer a cupon!
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That’s a good joke! What about shipping fees???
I think that if we gather as a group and open a complaint to them we will have more influence.
The way they handle this is ridiculous. The same with the issue I had with them when JLCPCB
system chose the incorrect USB port for me, they didn’t help at all in that case.
I’ve talked about the hole and vias before for the DRV ground pad. I’ve changed to using just vias. Yes I’m aware my approach for this is unorthodox to traditional PCB design but I’m trying to enable DIYers with only a regular soldering iron. Give and take.
5 Likes
Was this happening only during braking? If so, looks like the regenerated energy is causing the supply voltage to spike.
Two approaches here. Reduce negative motor current or try adding some more bulk capacitance to the DC link. You could try tacking on 1 or 2 more of those 330uF caps.
you could also try to increase the max voltage setting in the VESC tool to say 59V to keep it from triggering but this is a little riskier.
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looks like the drv issues are back. I wonder if even the “good” ones are still not performing quite right.
The following faults were registered since start:
(tried lowering motor amps, will lower it further)
Fault : FAULT_CODE_OVER_VOLTAGE
Motor : 1
Current : -19.8
Current filtered : -19.3
Voltage : 59.02
Duty : 0.108
RPM : 9193.3
Tacho : 85796
Cycles running : 92484
TIM duty : 910
TIM val samp : 4200
TIM current samp : 4200
TIM top : 8400
Comm step : 0
Temperature : 34.15
this one presents itself as the board seeming to go full reverse when I get to about half throttle-ish. I’m not sure if it’s actually going full reverse, but it sounds like it and the motor/wheel locks up and kinda tosses me off (haven’t had any bad wipeouts yet, but i have started wearing full pads with my helmet lol)
Fault : FAULT_CODE_DRV
Motor : 1
Current : 3.8
Current filtered : 9.8
Voltage : 41.09
Duty : 0.579
RPM : 27161.4
Tacho : 200540
Cycles running : 50181
TIM duty : 4867
TIM val samp : 4200
TIM current samp : 4200
TIM top : 8400
Comm step : 0
Temperature : 36.43
DRV8301_FAULTS : | FETLC_OC | FETHC_OC | FETLB_OC | FETHB_OC | FETLA_OC | FETHA_OC | OTW | OTSD | PVDD_UV | GVDD_UV | GVDD_OV |
I have a legit DRV from digikey (nine h*ckin bucks), would it be an interesting test to see if swapping it helps?
1 Like
Lower the negative battery current too. I think that actually has more to do with the issue.
If you get a severe enough fault like the last one where it throws every fault in the book, you need to power cycle the controller. Reason being is that it loses its saved current sense gain value and goes back to default. Has to be reset to be corrected
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do you think the braking issue is a limitation of the design, or more likely related to my implementation (soldering etc)
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If I recall correctly, braking with a 12s battery at full charge does some wonky stuff on most controllers not just this one.
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@alwaysmohawk its the controller’s design and/or ability of the battery to absorb regenerated energy.
The improvements I’ve done to v1.0 should help a little with this. More bulk capacitance in the DC link and some gate drive stuff to dampen transients and voltage spikes even further. We’ll see though. The DRV will still have a max operating voltage of 60V no matter what.
5 Likes
Also the issue with the DRV losing its current sense amp gain setting will be solved in v1.0. I’m just changing the hardware slightly so that it just works with the default values. This will also make it easier to merge the code into the official VESC project for official support.
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