VESC Temp Concerns

Hi guys,

I’m concerned about the temperature of my VESC, today I went for a short ride (4.4km) and the temp reached 55ºC (131ºF), it might not sound that bad but it’s -11ºC (12.2ºF) outside, which is kinda of cold… The peak occurred going up at the end of a slight hill (maybe 10m over 1km), just going downhill the VESC was already reaching 34ºC (93.2ºF).

I’m running a single 190kv 63mm motor from DIY with a 10S5P, I’m about 80kg / 175lbs. Here is the ride:

So basically my question is, is it normal?


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@pyttroll - Did you get a VESC from DIY? If so, you might have gotten a bad VESC which has a damaged R1 component. You can ship it back and we can send you a new one and/or you can replace the R1 component. Let me know.

Yeah @torqueboards I got it from you, how expensive is that R1 component? And how easy is it to change?

@pyttroll, how is your VESC enclosed? If the FETs were open to the air, then I would say 55° is extremely hot, but if it’s in any kind of case, and with shrink-wrap over the FETs, then I suspect there is just too much insolation for the outdoor temperature to matter once it heats up inside. If you let the board sit for 10 minutes, THEN you’d get a ton of power, but once the heat shrink and foam warm up, that effect wears off.

I haven’t implemented any sort of cooling on my VESC, and so going up a steep enough hill to cause 100% current draw brings my FETs up to the 80-100°C limit in about ~10 seconds. I know 100° is hot, but the only problem I think I’d ever have is melting the foam tape I use to cushion the inside of the enclosure.

Hey @Montiey my VESC is in a tight 3mm ABS enclosure, sharing space with part of the battery, a buck converter and an anti-spark switch. I don’t seem to have a loss of power when the temp goes up.

@pyttroll It’s a fairly cheap component. I’d have to double check and it’s easy to fix since it’s on the outside.

If you didn’t want to deal with changing it out though you can just send it back. We have a new batch that should arrive today. I’ll send you a PM with more info.

@Montiey - It’s specifically a bad R1 sensor so it’s not actually hot. Awesome answer though :slight_smile:

EDIT: Torqueboards just confirmed R1. That’s what I get for taking too long to reply! :stuck_out_tongue:

Hmm… I’m reading now about a bad batch of VESCs from DIYElectricSkateboard. I would investigate the accuracy of those temperatures… If you can, take it out of the enclosure, and see what it reads idle outside, and inside. For example, I would expect 20° inside and -11° outside.

@pytroll - Actually, I think yours might not be that issue. At least, I don’t think yours was part of the bad batch since your order was before the fact.

After your VESC has been sitting for a while can you connect to it and check the real time data tab for what the mosfet temp is?

From actually reading your initial post the symptoms are actually different so @Montiey this might be a different issue.

Yeah @torqueboards, it reads 13.6ºC right now, which is my garage temp, so the sensor seems ok.

Interesting. So that’s not the problem, then, unless the sensor only becomes inaccurate at higher temperatures.

Perhaps you could post your BLDC tool settings pages? If this isn’t in fact a hardware issue, then that’s probably where we’ll find the problem.

Here you go:

Put batt max at around 30amp. That should help. But also don’t really take for granted the data from the app, specially if the outside temperature is bellow -10, we’ve got some weird data last time we try a board at low temperature :wink:

Also your way over the temps cutoff, so if the data was right it should had slow you down.

Has it done this before? I’d try riding again and see if the issue comes up again.

Where is the sensor located? I ask because if you can rub it with a finger or give it a little warm air from a blow dryer, etc. you might be able to see if it reacts accurately.

I thought they were integrated into the FETs but I can’t be sure.

Thanks for the advice @JohnnyMeduse, the biggest draw logged by the app was 24.6A so I’m not sure reducing the batt max to 30A would help, unless the reading for the amps is also wildly innacurate…

could it just be the units that are wrong? your starting temp is 23deg, if in F that would be -5C, which sounds right

I thought about that but the temp is good when the board has been idle for a while…

Does the app read anything related to the motor temps? If you don’t have a motor sensor, then obviously you should disable it if possible. Try setting the motor start and end values to 0 and see what happens.

You just want to be sure that everything is under control, I’m still not sure is the app might have some delay, or don’t show you fast peak current. Don’t forget that these are app and give you a average data, they are not precise as a thousand dollar meter can be.

For a normal VESC 4.12 in a enclosure without heatsinks this is absolutely normal. For a single drive the normal VESC get’s temperature problems. So once you reach 80 degrees it will start to reduce the power. Add some passive heatsinks and it will get better. When go up a long hill my single easily overheats.

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