Can you link me to this? I wasn’t aware you’re not supposed to use the 5v pin on the can bus
Hello all,
I too will be joining the ‘Replace your DRV8302 chip’ club…
Luckily I am in college at Georgia Tech and we have a workshop with professional rework equipment.
I noticed that my VESC seems to have also lost it’s C26 capacitor, can anyone tell me what exactly that does?
Replacement parts have been ordered from Mouser based on the BOM on the VESC GitHub.
After the board stopped working (I was running FOC mode with long wires) I tried to plug the vesc in again for power and it short-circuited and blew the DIY electric skateboards power switch I had on the board and vaporized the nickel strip attaching the positive wire to the battery.
Based on this, I am a bit hesitant to try the VESC again, even after I fix it.
So a few questions:
- What does the C26 capacitor do?
- I see that some legs of the DRV are fused, it that the issue?
- Is there anything else that looks abnormal about the VESC?
- Anything else that could have lead to the short
- Can the VESC be powered from a lab bench power supply? (Because those have short circuit protection and more importantly wont cause fires)
C26 is mostly use for adding capacity over FOC option, without it you will most likely burn the drv, also if you bought your VESC from DiyElectricSkateboard it is normal they use the BOM for the 4.10 version, witch don’t have the c26 capacitor.
The drv have two set of pin that are short, you can always refer to the schematic available on vedder web site.
and yes you can power it using a bench power supply.
And if you need someone to replace you drv, maybe I can help you.
http://www.electric-skateboard.builders/t/johnny-vesc-repair-services/11267
So if I add the c26 capacitor and do a c18 mod with a 4.7 capacitor I should be much better off running FOC?
Because I’m on a college campus and occasionally ride through buildings and need a quiet board, my plan is to run dual VESC setup in FOC mode, but the way my board is laid out means I will have about 40cm of wiring between battery and VESC.
I am currently using 12gauge flat wire, should I double up on that?
Also, can I combine the capacitor boards of the 2 vescs into one larger capacitor board and then pass wires from there to both vescs? (Cheaper and easier than buying different capacitors if it works)
Just adding C26 will help. The mod with the 4,7uF is a bit more complex and dosen’t require to change c18.
Also, yes you can combine the 2 capacitor board into one, but I highly suggest that you change the capacitor for bigger one, but I can be done.
For the flat wire I’m not a expert but If can double it, it should be better.
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Thanks. Very nice dual VESC holder concept.
Which capacitors would you recommend? As in what is the biggest capacitor pair that I can use?
Also, my build thread is up now: http://www.electric-skateboard.builders/t/boosted-pro-loaded-vanguard-rear-dual-6355-sensored-18650-10s2p-with-bms-dual-vesc-in-foc-custom-kydex-enclosure/13236
Here are also some pictures of my burned VESC. You can see the burned DRV and missing C26. Parts have come in from mouser, and I will attempt the repair after my thanksgiving break.
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In is setup @Blasto have use 2 x 2200uF instead of 6 x 680uF witch give approximately the same capacity.
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Cool. I think I will go with either 2 or 3 or those to make sure that FOC works reliably.
Also, I have decided that I will braid 3 strands of the 12amg flat wire together and then inlay and epoxy it into the board a bit. That should give me plenty of capacity to push through the wires.
OMG, joined the club
8s BLDC, nothing fancy.
I think it was while pushing the board unpowered. 
I noticed it suddenly locked the motor.
The following faults were registered since start:
Fault : FAULT_CODE_DRV8302 Current : -0.9 Current filtered : 0.8 Voltage : 30.32 Duty : 0.02 RPM : 72.2 Tacho : 8 Cycles running : 3 TIM duty : 792 TIM val samp : 421 TIM current samp : 23542 TIM top : 46242 Comm step : 3 Temperature : 25.85
I you feel any resistance, it’s probably the motor who’s burn (shorted phase)
And also maybe burn the drv
the motor runs free, it locked while pushing the board unpowered, but then freed again. Its not a deal with other ESCS ive dealt with but IDK if this could have caused the damage.
Ok if the motor run free when unplug… it’s maybe one of the mosfet who’s shorted… because there no protection against overvoltage, wich can damage the gate of a mosfet.
It runs free plugged in too. Can the FETs cause DRV faults?
No if it runnig free when plug, it’s probably the drv, sorry 
Now it’s not giving any more DRV faults, only Under Voltage Fault, motor stutters a bit but doesnt turn. Ordered 3 DRV chips, lets have a go.
Now I get this Fault : FAULT_CODE_UNDER_VOLTAGE Current : 61.5 Current filtered : 63.1 Voltage : 7.18 Duty : 0.28 RPM : 449.4 Tacho : 196 Cycles running : 633 TIM duty : 3520 TIM val samp : 1688 TIM current samp : 7977 TIM top : 12578 Comm step : 6 Temperature : 22.90
yea 7 is definitely undervoltage. Check your cells!
Cells are good. When I just got it, I could do detection on this motor with a current limited supply no problem. Its sounds fishy that the current goes so high. Something is causing the voltage to drop drastically. The motor spins erratically on KB control. I wanted to try reflashing the FW. maybe, who knows… Funny the DRV faults went away for good.
It could still be the DRV being broken. Maybe it’s not providing the correct voltage which leads to the undervolt error.
Fumbling around I can make the motor spin, detection still wont work. The behaviour is very erratic, different from when it arrived…
stranger things…