BKB dual surging and out of ideas

How-Tos & Esk8 mechanics Esk8 Mechanics
#1

So I’ve had my dual sense late fall of 2019 and it has worked flawlessly (apart from a small charging issue what I later found out was a blown circuit). About 2 weeks ago the board started surging when I give it throttle. I hooked it up to vesc tool, updated it to the latest firmware, and set everything where it should be. I have checked all the connections and wires and everything looks good.
Does anyone have any ideas what this could be from? I am not sure if it is a connection problem because apart from one incident where it locked up, it only happens on acceleration. The vx1 is ppm. Here are some video snips from when it happens.
https://drive.google.com/drive/folders/1dBCnT-EmNmvkRyzaXKj7ifQACIRuOZ9s?usp=sharing

Quack

#2

Hook it back up to vesc tool on the bench. Run your motors. If the issue happens, go to terminal and type “Faults” and see what it says.

1 Like
#3

I have. No faults.

1 Like
#4

Does the issue happen under no load (on the bench)?

1 Like
#5

Not that I have been able to tell, no.

1 Like
#6

So only while you’re riding then?

Can you post your vesc settings?

1 Like
#7

Might be worth installing either a fresh version of the FW youre running now or downgrading to a firmware that is considered stable

1 Like
#8

20200408_193258
20200408_1932584032×2268 4.57 MB
20200408_193318
20200408_1933184032×2268 3.48 MB
20200408_193335
20200408_1933354032×2268 4.62 MB
20200408_193341
20200408_1933414032×2268 3.91 MB
20200408_193346
20200408_1933464032×2268 2.78 MB
20200408_193325
20200408_1933254032×2268 4.68 MB
20200408_193358
20200408_1933584032×2268 4 MB
20200408_193416
20200408_1934164032×2268 4.06 MB
20200408_193426
20200408_1934264032×2268 2.05 MB
20200408_193429
20200408_1934294032×2268 3.31 MB

1 Like
#9

Just for laughs, try 40/-40 and see if that changes anything.

1 Like
#10

it looks like the 4.2’s are cutting out, might be too high of a motor current.

1 Like
#11

Definitely not that because it is my 80 pound brother and he uses about 1/4 throttle in green mode.

#12

Fsesc 4.2’s have been known to cutout at 30a, and realitevly light people.

1 Like
#13

I have tried changing all the motor and battery current settings and got the same result. I even tried making the end in .69

1 Like
#14

tried it in BLDC sensored yet?

1 Like
#15

No, just foc.

1 Like
#16

try it in BLDC and see how it does, cheap esc’s generally react better with BLDC

3 Likes
#17

Good call. The 4.20 before upgrade was better in bldc.

2 Likes
#18

What firmware would you consider stable, and where could I find it Also, doesn’t the setup wizard force you to use the latest firmware?

#19

3.62fw and don’t use the wizard

Learn to configure it manually:

This video shows it for vesc tool 2.0 (which I think is more complicated )

This is for BLDC tool, the version I think is easier to navigate. This will be ‘outdated’ but you can still learn about all the values you need to correct/change

2 Likes
#20

it looks like the battery is the problem. If your BMS is not bypassed for discharge, sometimes my BMS cuts current supply to protect the cells when the battery is low (to prevent the cells from sagging too low). And it behaves exactly like this. Could be your battery pack if damaged or the BMS is damaged and is reading a voltage too low and then cutting out power.