On the lower settings, it is the same - full throttle = fall off from the skateboard. But I would like you to show something that may be interesting. I used VESC DataLogAnalyzer to observe what is happening during motor coggling and it seems, that it does not receive enough current from the battery (I use BMS in charge only mode).
If you take a look at a picture, you will see that at moment 1 engine should start spinning faster and faster, but it didn’t start spinning until moment two (was coggling between moment 1 and 2). Am I right that there is something wrong with the battery?
that is above my paygrade, but it is weird behavior compared to before. Motor current goes up like crazy but the battery is not delivering. Did you inspect the battery for any damage? I am by no means an expert, but it seems to come down to the battery. @pat.speed can you look at what he postet. i have no eduacted guess left but battery.
Ok, here I registered the moment in which skateboard stopped/started coggling during acceleration (in result I fell off the skateboard):
It looks that before the skateboard stopped there was the decrease in current both on the motor and battery. Tested spec:
- current motor 40A/-30A
- current battery 30A/-30A
Specs that I was able to ride slow (AF) but safe were:
- current motor 20A/-20A
- current battery 20A/-20A And
- current motor 30A/-30A
- current battery 30A/-30A
did you a full visual inspection of all parts. especialy the battery?
All except battery looks good, I will check the battery tomorrow as I decided to change some cables around battery after switching BMS into charge only mode. However, because of the last chart that I posted, I will also call my VESC manufacturer on Monday.
Hi, generally I probably solved the problem (I say probably because I have to test it more). I did several things and don’t know exactly which one solved the problem so I will describe all of them:
-
wires from the battery to the VESC - I soldered them again changing phases just in case
Also, I double checked if any of the phases don’t interfere with another one (the result of bad work during soldering wires to the VESC). -
checked battery - I found out that one cell was disconnected (probably it was a result of disassembling the battery, so I don’t think it was the reason of the problem with a skateboard - but you can check it just in case)
-
last one and I think the real reason for my problems with the skateboard - lack of capacitor between battery and VESC!
Yes, I know, you can call me ignorant etc, you can ask how did you omit this part? Well, I’ve naively thought that if I buy VESC then I have everything I need. But on Sunday I took a look on the VESC schema and I realized there is lacking part in my build. So, I installed 2200 uF capacitor and the skateboard works perfectly.
Best regards, Arek
weird. but if it works it works.