14S VESC ?

General topics and discussions about the VESC and its development.
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Ecyclist
Posts: 30
Joined: 24 Jun 2017, 01:26
Location: San Diego, CA

Re: 14S VESC ?

Postby Ecyclist » 25 Dec 2017, 18:50

Unfortunately, I don't have a test station to measure efficiency of electric motors. I can build almost anything and I have tools for that, so maybe one day.
About theses Chinese motors. I suspect that they are all made in one mega factory, but I can't find anything over 63 mm on Maytech website.
TheFallen, can you please post a link to the Maytech page with 80 mm and larger motors? It took me forever to find two different 8072 motors and I would love to have one extra source.
BTW: How are you doing with your robot combats? 18 years ago, my neighbor was into battle bots and asked me to join, but I was too busy making money at the time.

mdagbro
Posts: 2
Joined: 25 Dec 2017, 23:06
Location: Sweden

Re: 14S VESC ?

Postby mdagbro » 25 Dec 2017, 23:18

Hi guys.

I've messed up and bought a VESC for my 13S5P E-bike. I didn't do enough research beforehand, I thought the 60V input rating meant that it would take my 54.6Vmax battery, but now I know the voltage on the input side can well exceed the battery voltage. How screwed am I?

Will I be OK if I limit regen to a low current, trying to keep input voltage below say 57V? I have real brakes too so limiting regen wouldn't be the end of the world. Or will the input voltage exceed battery voltage even when driving forwards?

My VESC is one of those heatsinked, heatshrinked ones, and it has 2x 63V 470 uF Rubycon YXJ caps soldered directly to the board. Should I add more? Battery leads are ~25 cm in total.

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TheFallen
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Location: UK
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Re: 14S VESC ?

Postby TheFallen » 26 Dec 2017, 02:15

I've heard they're fairly responsive over email which is the best place to go for custom/specials.

But for links try Alibaba: https://maytech.en.alibaba.com/product/ ... e_uav.html

Doing alright in general, but the lack of decent ~160A ESCs is limiting. Our team page is: https://www.facebook.com/teamcyberwar/

ThierryGTLTS
Posts: 86
Joined: 09 Aug 2017, 11:10

Re: 14S VESC ?

Postby ThierryGTLTS » 26 Dec 2017, 10:54

mdagbro wrote:Hi guys.

I've messed up and bought a VESC for my 13S5P E-bike. I didn't do enough research beforehand, I thought the 60V input rating meant that it would take my 54.6Vmax battery, but now I know the voltage on the input side can well exceed the battery voltage. How screwed am I?

Will I be OK if I limit regen to a low current, trying to keep input voltage below say 57V? I have real brakes too so limiting regen wouldn't be the end of the world. Or will the input voltage exceed battery voltage even when driving forwards?

My VESC is one of those heatsinked, heatshrinked ones, and it has 2x 63V 470 uF Rubycon YXJ caps soldered directly to the board. Should I add more? Battery leads are ~25 cm in total.


Yes you are right about regen limitation, if you don't wanna blow up your MOSFET and DRV :!:

Your set-up seems to be OK.

Thierry

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Ecyclist
Posts: 30
Joined: 24 Jun 2017, 01:26
Location: San Diego, CA

Re: 14S VESC ?

Postby Ecyclist » 26 Dec 2017, 17:47

mdagbro wrote:Hi guys.

I've messed up and bought a VESC for my 13S5P E-bike. I didn't do enough research beforehand, I thought the 60V input rating meant that it would take my 54.6Vmax battery, but now I know the voltage on the input side can well exceed the battery voltage. How screwed am I?

Will I be OK if I limit regen to a low current, trying to keep input voltage below say 57V? I have real brakes too so limiting regen wouldn't be the end of the world. Or will the input voltage exceed battery voltage even when driving forwards?

My VESC is one of those heatsinked, heatshrinked ones, and it has 2x 63V 470 uF Rubycon YXJ caps soldered directly to the board. Should I add more? Battery leads are ~25 cm in total.

I'm sorry to tell you this, but I don't think that your VESC will survive that set-up.
Too high voltage, re-gen at high voltage or small caps with re-gen can kill VESC. You have all three stacked against you.
I hope that I'm wrong, but I doubt it.
You might have more luck without the re-gen.
E-sk8 forum is the good place to read about this. These guys are using re-gen for braking and blowing VESCs at 12S on a regular basis. https://www.electric-skateboard.builders/
If you decide to go for it and it works, please let us know. And if it doesn't, you can claim that you did it for science and for that you will be eligible for 5 extra points on the Richter scale. :D
Good luck and have fun.

mdagbro
Posts: 2
Joined: 25 Dec 2017, 23:06
Location: Sweden

Re: 14S VESC ?

Postby mdagbro » 26 Dec 2017, 18:40

Thanks Ecyclist! Do you think it's safer if I add two of these in parallel with my 2x470uF?

https://www.electrokit.com/uhe1j102mhd- ... 35-5.48500

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Ecyclist
Posts: 30
Joined: 24 Jun 2017, 01:26
Location: San Diego, CA

Re: 14S VESC ?

Postby Ecyclist » 26 Dec 2017, 18:52

TheFallen wrote:I've heard they're fairly responsive over email which is the best place to go for custom/specials.

But for links try Alibaba: https://maytech.en.alibaba.com/product/ ... e_uav.html

Doing alright in general, but the lack of decent ~160A ESCs is limiting. Our team page is: https://www.facebook.com/teamcyberwar/

Thank you for links.
These robot combats look like tons of fun. I also like your idea of using banana for scale. It really helps to realize how big these monsters are.
I think that I will join a local team and try my luck.

I checked the link for Maytech motors on Ali and found it hilarious.
According to these specs, 12090 motor is 74g and rated for 446W. Just goes to show you how incompetent the Chinese sellers are.
It looks like the only thing they can do is copy and paste.

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Ecyclist
Posts: 30
Joined: 24 Jun 2017, 01:26
Location: San Diego, CA

Re: 14S VESC ?

Postby Ecyclist » 26 Dec 2017, 19:00

mdagbro wrote:Thanks Ecyclist! Do you think it's safer if I add two of these in parallel with my 2x470uF?

https://www.electrokit.com/uhe1j102mhd- ... 35-5.48500

It will be safer, but still no go in my book. Maybe it will work if you keep your 13S at low charge. That is my plan but without re-gen.
Marry Christmas. I'm assuming you have two days of Christmas in Sweden.


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