I bought a Hobbywing ESC - Is this our Holy Grail?

AlexLTDLX

AlexLTDLX

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Hi all - I've been innundated with all kinds of stuff. Life was supposed to ease up by now, but instead things got even more chaotic. But I'm still doing my best to keep up the research on my end. This Black Friday I took advantage of another sale on a P2 supercharger (for those counting at home, I now have 2... for good reason...) I have yet to unbox that thing. What I DID unbox yesterday was the Hobbywing EzRun Max4 ESC. It's rated for 300 amps continuous (2,000 (!) amps peak); but the bummer is it's only good for 50 volts (12s). However, on lower-power applications (say under 600-650 hp), it should be ideal. Also good for multi-compressor setups (that's why I have have two P2 units).

Mine didn't come with a sensor adapter cable (it was supposed to, apparently there was a run of these recently that didn't have them), but I reached out to the company and we'll see what they say. A good test for company support. Even so, I used the LCD programmer, and got it running in a few short minutes. There are a few quirks for our purposes, but there are a few benefits, too. After the VESC nightmare, having both the MGM and now the Hobbywing just working out of the box is a reminder of how things should be. I was running on 8s (my small 6ah lipos); and I saw ~150 amps in a quick test - enough for the blower to blow itself around on the desk - and with the beefy aluminum base, it's about 20 lbs or so.

The best part - it's less than $450 USD; making it less than half as expensive as the small APD ESC (which was rated for 400 amps continuous, but the programming software showed a 300 amp max; though that one was good for 63 volts) and less than a third of the cost of the bigger APD or the MGM.

I'll make some videos on this as soon as I possibly can:
HobbyWingCU.jpg
HobbyWingWS.jpg
 
AlexLTDLX said:
Why not?
Click to expand...
Well .. for a start the wire gauge is far to small.

Also in the RC world "continuously" doesn't literally mean running at 300 amps like you'd expect.

Lastly it probably doesn't have any limits to ensure that the current stays under 300..

I would expect this to be like the "flyers" ESC's where it lasts for a while.

An electric motor draws more current at 0 rpm and less at high rpm. This therefore means that when the ESC is being used the manufacture will expect the current draw through the ESC to vary too and not sit at a constant 300amps.. For the ESC to deliver a constant 300amps it would need a means of limiting the current to 300. Now ASSUMING that this ESC doesn't have a means of limiting the current to 300amps then they are expecting the current not to be anywhere near 300amps constantly, other than an occasional burst over this..

So at 300amps "real Constant" the question will be how long will it last. This is the unknown answer.
 
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We'll find out. I intend to torture test this thing on video soon. I will say it's a good deal beefier than the small APD ESC; not that that's decisive, but I'm always willing to give the benefit of the doubt. The fliers were downright spindly by comparision (and weighed proably a quarter as much). The 2,000 amp peak probably reflect the MOSFETs' peak combined power rating. I can tell you the VESC has 900 amps of MOSFETs in it, and it's also rated for 300 amps. That's why I was able to run it with 400+ amp phase currents; but I was also carefully monitoring everything because I was having so many other issues with it.
 
The other thing i forgot to say is that the manufacture would have never guessed that it would be put in a hot engine bay, which would reduce the max continuous power greatly.

Also i have always assumed manufactures ratings dont assume that you will be applying max volts and max current at the same time as this would result in the mosfets having to dissipate way more power ( heat ) at max volts than min volts.

With no Temp monitoring or Current monitoring on these dumb ESC's how can you ensure you keep within their "Limits" ?


The vesc has a somewhat believable max current over long term usage because
A it has Current limiting and
B has Temp limiting.
C has 3 wires in and out for delivering the current.
I still wounder if you would have had the issues with the VESC if you just used it on BLDC mode like all these other ESC are running in. On that thanks for the testing you have done on all these ESC's i think it's been a literal life saver (and money saver)

Didn't the MGM 40063-3 also die .. it' lasted a while then stopped working just like alot of other ESC's

This Hobbywing ESC might be great but it seems hard to believe.
 
Unfortunately, the VESC just doesn't perform in the real world. I did try running it in BLDC mode too; it just wasn't up to the task. I think a big part of the problem is turning out to be the 6 pole TP motors. That's a lot of eRPM and many ESCs seem to get unstable. WB's ESC did die, but he was also running a 6 pole motor. I'm thinking that maybe switching losses have something to do with it. My LMT motor is only 2 poles. While that gives up torque (not really important down low for what we're doing), it incurs less switching losses. RPM is both our friend and enemy. Honestly, the APD units were pretty good too, except their physical designs compromised an otherwise good electronic design. The MGM seems decent too. Hobbywing has a lower rpm, higher torque motor that might work if I gear up the P2 supercharger. That's ultimately where I think this is going. The motor/ESC combo would cost 1/3 of the MGM/LMT combo, but provide over half the performance. Everything would be pushed less hard.

I'm going to try to shoot a video here very soon where I torture test the Hobbywing/Castle combination. I feel the weak link will be the drive belt. If life didn't keep getting in the way (things are bad and very busy right now) I'd have already gotten through all of this. Fortunately, the end of the tribulations are in sight, for better or for worse; but still major hurdles to overcome on 3 separate (and unrelated to this) fronts.
 
Well you are right about the higher pole count resulting in higher Erpm for the same rpm .. resulting in more switching losses.
 
Every night I put in a few hours cabling/setting stuff up for the test. I've got power, control circuitry (but not cable - I'll make that tonight), current measurement & rpm measurement worked out. Just need to extend the RPM sensor.

I discovered a few interesting things:

- The Kemet Caps I use have an ESR of ~4.3 milliohms by themselves (as measured by my ESR meter
- With the 16' 2 gauge power cables I have, the total ESR goes up to just under 12 milliohms
- At 300 amps, that means a voltage drop of 3.6 volts
- The batteries I'm using have an ESR that averages 6 milliohms for the 9ah packs and 7.3 for the 6ah packs (and average total in a 12s2p configuration of ~20 milliohms)
- At the same 300 amps, that gives a projected battery voltage drop of 6 volts

This gives us a projected total voltage drop of 9.6 volts. I'd say look more for 10-12 volts; off a 12s pack, we're only going to see 38-40 volts total. At 800kv, that's 32,000 motor rpm. The current pulley step-down is 14/18 - .778:1. Giving us a best-case impeller speed around 24,900 rpm. That's at 300 amps. At 200 amps, we could see 27,385 impeller rpm (a bit over 35,000 motor rpm).

It'll be interesting to see what we really see. Fire and explosion is also an option.
 
Have you seen any ESCs using GANFets? GANFets are taking over switching power supplies and digital audio amps, offering higher switching frequency and ~ double the current capacity for the same size compared to MOSFets.
 
It was a black friday sale. $625 is the regular price, and honestly, still a good deal. I just took a quick look and GaNFets and they look to be a potential game-changer. I wonder if the reverse conduction characteristics might be a problem for ESCs and the associated back EMF.
 
Just finished the first round of high-power testing with the Hobbywing/Castle setup. We hit 9.5kW continuous and everything held up fine. If we can get to 13-14kW I'm sure it'll support 650hp. Our tests today show the current setup is good for 550hp at about 5 psi. Video coming soon.
 
welcome back! I tought you shut the forum down because mine wase down for a good month. anyway I had a light of hope on my side! I ship back my ESC so they can repair it the september 15th I think and the ESC finally arrived to the contry monday this week hahah glad it's winter and I can't do anything anyway.
 
Hahaha not that bad for now! Its stay arround -10c. and a lot of snow! But we will probably see a lot colder then that next month 😅
 
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