Board cuts out under load / when accelerating (Nunchuk & VESC)

[Charlie_H]

Although there is already some information out there on how to stop the nyko nunchuk remotes from cutting out, i am still having problems with mine.

Upon acceleration (even on flat ground) when the throttle is around 90% the board will momentarily cut out and then keep going, it also does this when going up hills

-I have checked all my solder joint and have only one wire for each connection going directly from the receiver to the VESC (previously i had a JST connector.) -Shaking the board and pulling on wires does not make the board cut out, it’s only under load. -The board runs off of two 4s lipos in series. although i have tested it on a 6s and it still happens -cut outs still occur even when not cased in aluminium housing. -I have changed my low voltage cutt off to well below the necessary level to check that the vesc wasn’t getting confused and thinking the LiPos were flat.

The only other thing i can think of that i have done wrong is set my settings wrong in the BLDC Tool.

Please if anyone has any other potential solutions, ideas on how to fix it, or the very least ways to rule out certain things it would be greatly appreciated!

Thanks!

[flatsp0t]

Sounds like you trigger the over-current cutoff. Could you please do some screenshots of your BLDC tool configuration tab? Or could you tell me Motor-/Battery Max values and your battery ratings?

[Charlie_H]

Admittedly, I Iack knowledge about the BLDC Tool so hopefully it’s a simple fix.

NOTE: the voltage cut off has intentionally been set super low as to check that was not not the problem.

[elkick]

Better set max input voltage back to default 57V.

There are too many tutorials out there giving the wrong advice to lower that value and it always leads to those problems and questions.

[flatsp0t]

You battery max input voltage seems too low, voltage spikes can cause a shutoff.

[Charlie_H]

I’m running the board off of 30 volts. Do you think 40 volts is high enough?

Also what is the purpose of this function?

[elkick]

It prevents the VESC of taking a higher voltage than it can handle. And that’s 60V, so it’s safe to leave that value at 57V.

[Charlie_H]

I see, Thank you for your help! I will adjust my settings accordingly and see what happens. Fingers crossed.

[Charlie_H]

Problem is still occurring , Please if anyone has any other suggestions please let me know.

[Ackmaniac]

Please show us pictures again of your current settings. And also add a screenshot of the advanced screen in motor config.

[Bender]

I had very similar problems in FOC (but not in BLDC)

I did some research and you can set the vesc to a absolute max of 240 which prevents abs over current spikes when breaking or accelerating hard Default is 130

[boards]

Try adding a (4-20)uf cap between 3.3 and on the vesc side. I think the 3.3 line just sucks.

[Charlie_H]

[Namasaki]

your battery max current seems too low. Your Lipo batteries should be able to handle more than 25amps. AH x C = discharge capability example: 5000mah = 5ah x 20C = 100 amps continuous discharge capability. If your batteries are 5000mah with a 20C rating you could set your single or even dual vesc much higher on the batt max amp. I think your cutting out because your not feeding the vesc enough current from the battery It’s like your running out of gas as you accelerate. Funny, I had a similar problem on my Jet Boat. 350 chevy with a 4 barrel carb and a stock mechanical fuel pump The motor would start and idle but as soon as I punched it, it would die. It would start back up and idle no problem, but every time I hit the throttle it would die. The solution was a high volume electric fuel pump. After I installed the new fuel pump, it ran great! The mechanical fuel pump just couldn’t supply enough gas.

[Charlie_H]

I’m running the board on two 10ah 4s lipos in series, each rated up to 10c. is 100 amps a safe number though? i left that value as the default 25 because i was paranoid about damaging something. I’m a bit nervous to increase that value by more than 4 x without fully understanding the implications of doing so.

I will look more into it! thanks for the tip!!

[Namasaki]

Those batteries can deliver 100amps continuously. If your running a single vesc, try raising the max batt current to 50a and see if that fixes the problem. The battery max current setting is for protecting the battery. So even at 50a your way under what the battery can handle. while your at it, you might want to turn the motor max current down to 50a. The Vesc is rated for 50a cont output

[Charlie_H]

I will give it a shot! assuming that problems still occur after i test 50amps, is it safe to continue to increase the batt max by + 10 too see if it stops? all the way up to 100 amps? thanks again for taking the time to help me

[chris.hunt]

Hey how do you like you nunchuk remote I am looking and remotes and this one popped up on my radar.

[Ackmaniac]

You have the Firmware with the bug in Min current ramp step. It always increasdes by the factor of 10 when you read and write the settings. Get the latest firmware or always check that value before you write your settings. By default it is at 0,0400. This can damage your vesc. Maybe that is also the reasen for your issues,

[Pyrax]

I had a similar problem with my board. Whenever accelerating or braking, about 2 seconds later the board would just stop responding until about 1 second later. It was due to there being a poor connection between the remote (winning remote) and the receiver. I moved the receiver to a better location and it worked fine. Maybe try your board with the receiver on the outside? (btw this also did only happen whilst the board was under load)