2 VESCs dead in 1 week?

hmm, not too lucky with my trampa - first a DRV8302 blows up with a poof and lots of smoke when I tried FOC with PPM and current noreverse settings (i pressed write and it was gone when I pressed the throttle on my remote). and now, after riding for a little with 1 motor and the remaining vesc, this one blew up too.

what i wanted to test was uphill driving. my single vesc couldnt take any hills really, it got slower and slower up to a point where it was only crawling - a joke compared to my single vesc tesseract and even more of a joke compared to my dual torqueboard topspeed which is utterly stable with tons of torque. so, I went out with my laptop connected to see what the vescs problem was - everything was cool, just switched on, I suspected heat because it seemed to happen after a moment and the power on hills got increasingly worse - basically the board was slowly dieing on me.

I accellerated hard up the hill, laptop in my hand, remote on the other, board speeded up the slope for 20meter with normal torque ... and then it switched off. thought it was a soft off of the vesc, but when I opened the box all lights were out and it was simply dead and my laptop was disconnected. my settings were 80A motor current max, 60A battery max, connected was an SK6374!

these were the last life signals of the vesc - doesnt look critical at all? anyone got any idea what might have happened?

Im far from an expert on the matter, but I also noticed that my single drive 8s VESC setup cannot do hills. the oddest part is how my 6s setup with a hobbyking 150a ESC could, even with reduced gear ratio!

Should be more VESC's being tested soon too. I'll be doing a lot more testing too.

Sucks.. I wonder why it's not performing..

yea, i grabbed the torqueboard escs from my topspeed and the trampa was running like a dream up any hill!

the vesc thing felt like a heat issue, you can also on the screenshot see the steep increase of mosfet temperature. and on my other tests it felt timingwise like a heat issue. its weird cause i added heatsinks to the vesc and the same hill i took crawling with the vesc was easily taken with tbs escs and they were just ambient cool afterwards. :?

Yeah... I have a feeling.. we'll eventually have to upgrade with heatsinks with the vesc.

Ben on his forum made an update post a few days ago. http://vedder.se/forums/viewtopic.php?f=6&t=149

But it should at least handle that hill...

Have you checked with Vedder on what he say's about long motor cables vs. long battery cables? Longer motor cables could maybe introduce problems in the calculation/flux.

torqueboards said:

Yeah... I have a feeling.. we'll eventually have to upgrade with heatsinks with the vesc.

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its really weird cause it feels like the vescs are generating WAY more heat than your ESCs while they draw less current at the same time. I can tell from my battery heat, that your ESCs were probably close or even beyond 60A battery current whereas the VESCs were limited to 60A battery and 80A motor current ... and they were MILES off these currents in the screenshot before death ... and still shooting straight to 60°C, rising. and thats with 6 GFX memory coolers on each mosfet. your ESCs werent even mildly warm, just ambient temperature.

:?

The second one could be a bad stm chip or tvs diode or something else. Those are the first two components I would check. The trouble is some of these vesc's are made with the cheapest components you can find, many of the capacitors were switched out for other brands made with different materials and simply do not have the same properties at higher voltages. This all leads to a lot of ????? when something goes wrong. Best not to attribute the problems you are having with the design of the VESC without looking into these factors. Too many unknown variables to really know what initiated the failure. If you have trouble getting components or the shipping is crazy high let me know and I can send you some on first class usps.

Overheating on a single drive on steep hills is an issue for some. Heat sinking helps but if you are trying to pull to many amps it just delays the overheating outcome. The direct fets in the new design will create less heat due to less resistance and allow for a much more efficient heat sink. I think the TB 12s esc's use a direct fet and that is why you are seeing a difference.

chaka said:

The second one could be a bad stm chip or tvs diode or something else. Those are the first two components I would check. The trouble is some of these vesc's are made with the cheapest components you can find, many of the capacitors were switched out for other brands made with different materials and simply do not have the same properties at higher voltages. This all leads to a lot of ????? when something goes wrong. Best not to attribute the problems you are having with the design of the VESC without looking into these factors. Too many unknown variables to really know what initiated the failure. If you have trouble getting components or the shipping is crazy high let me know and I can send you some on first class usps.

Overheating on a single drive on steep hills is an issue for some. Heat sinking helps but if you are trying to pull to many amps it just delays the overheating outcome. The direct fets in the new design will create less heat due to less resistance and allow for a much more efficient heat sink. I think the TB 12s esc's use a direct fet and that is why you are seeing a difference.

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thanks for your offer, I sent my vescs in for repair @ http://www.lp-electronic.com/vesc/ which are related to the german manufacturer of vescs (http://www.esk8.de).

you saw the plots - do you think that amount of heat for that amount of battery & motor current is normal with an ambient temperature of roughly 10°C outside and 20°C inside the trampa battery box? :?

The temps started to increase after you attempted to run more than 60 amps. I wonder if this has anything to do with running a lower battery max than motor max. I use a bms with a max current of 80 to 90 amps so my battery max is in line with my motor max. FYI...limiting battery max does not mean the vesc will never exceed 60 amps, it simply acts as a buffer.

Also the VESC will overheat more easily if you are asking for high amps at low rpm, this may have more to due with passive ventilation than anything else. If your enclosure is completely sealed this can be a problem.

chaka said:

The temps started to increase after you attempted to run more than 60 amps. I wonder if this has anything to do with running a lower battery max than motor max. I use a bms with a max current of 80 to 90 amps so my battery max is in line with my motor max. FYI...limiting battery max does not mean the vesc will never exceed 60 amps, it simply acts as a buffer.

Also the VESC will overheat more easily if you are asking for high amps at low rpm, this may have more to due with passive ventilation than anything else. If your enclosure is completely sealed this can be a problem.

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from what I understand, phase currents can always easily exceed battery currents, thats why I felt 80A motor, 60A battery was the most reasonable choice (cause thats actually their limits). and you can see that the motor is at 60A while the battery is at 40A, thats still very moderate compared to currents that people pull off on these 40C lipos!

not sure what happens if the vesc hits these limits - soft backoff or these DRV_CURRENT_ABS errors with 2-3sec recover time most likely. that didnt happen to me yet, so I most likely didnt hit the limits yet!

and yea, I made 6x0.5mm diameter venting holes by now, basically a stream of air exactly past the escs. screw waterproof, I dont want to loose more vescs and I dont want to grill my battery either. :|