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Jobby Lane | Clutch Underdog | Carvon V2 Dual Hubs (ABEC 11s) | 18650 Battery Pack Undecided | Dual VESC


#1

Hey Guys,

I’ve been steady lurkin’ for a while now. I’m a huge fan of this community. You guys have inspired me to start my first build and get in the game.

I plan on using this board to walk/run my dog. I weigh 180lbs. The route is just over 1 mile and it’s relatively flat (however outside that route is fairly steep).

Here’s what I know so far:

The biggest unknown is the battery. I prefer to use 18650s for convenience. I’m trying to figure out if I can get away with a 10S pack. I see @AbrownMN and @LukeM are going with @torqueboards 12S3P. I would love to use this 12S3P pack too but it’s just a bit too long for my board once you add up the pack, VESCs, receiver wires and enclosure.

Some people get great results with the SPACE Cell and Carvon V2s. Is that just because they weigh < 180 lbs? I was hoping 10S3P would be enough since I’m only going 1.2 miles.

I mentioned the dog walking route was relatively flat. Here are the details of that route:


#2

Here is a video of Carvon V2 duals going up a 10% grade.
12s lipo
Torqueboards 120A 12s Esc’s
Half throttle
185 lbs rider
Amp draw for both motors combined going up this hill was 54 amps.
Amp draw would be more with 10s
Probably best to have a battery that can handle more than 50amps for climbing hills.


#3

Hola Hombre, welcome to the forums! Glad to see you decided to take the plunge. In regards to your battery question it would seem that most people, including @RunPlayBack aren’t complaining about the 10s Pack, though he may be a bad example because I think he’s like 130? Either way, the issue is moreso going to be the draw required from the battery to feed the two motors at high throttle. Some people experience cut offs when they get on top of it hard. Long story short, this is why I went with the 12s pack. You will probably be satisfied with the 10s pack, but you may have some cutoff issues under heavy load. Let me know if you need help with anything else. I have learned a ton since I started researching this project.


#4

I had issues with the space cells limitation of only 15 amps per motor. VESC can take 50 amps each and motors can take 80 amps. So limiting yourself to 15 amps means issues while climbing hills. I blew out a VESC while hitting either a heat limit or amp limit for an unknown reason.

My soltuion is I am going to up my amps to 25 per VESC, and I hope this helps.

My recommendation would get something that can pull 50 amps per motor (since that is the VESC amp limit) and 12s, since you will get more torque.


#5

Lol yeah I think I’m lightest one in here. @TheWrongHombre 10s pack is fine if your riding on flats. I’ve definitely had friends around 180 ride my dual board. If you’re over 200lbs a belt system is probably better. My components with dual VESC’s and Space Cell is around 21" in length so that should be plenty of room with your deck.


#6

You are right about the flats. I’m between 190-200 lbs, and I have no issues with the space cell and carvOn combo on flat. The hills become the issue, even medium to small hills.


#7

@Namasaki it’s awesome to see you’re taking on 10% grade on hubs. I have a couple monsters like that just outside the dog run.

Do you know how many amps you pull on 6% grade?


#8

Mucho gusto @AbrownMN!

Your build was a huge inspiration. Do you know how many amps the 12S3P will draw? Are you still going with that monster 25 inch enclosure? Will you have to make any mods to get it to fit the Vugenhausen?


#9

Not sure about 6%. I’ve only tested the amp on the 10%. We also have a longer hill that is about 3.5% grade and I can fly up that one easily at 20-28mph
The 3.5% is at the beginning of this video.


#10

Have the 180 pounders hit any hills with this bad boy?


#11

The new space cells states the following:

Space Cell PRO3

Pack rated to peak output of 60AMP, However incorporates a 40A Fuse for protection

Space Cell PRO4

Pack rated to peak output of 80AMP, However incorporates a 40A Fuse for protection

Am I right in assuming that’s 20 amps per motor now?

When you say:

My soltuion is I am going to up my amps to 25 per VESC, and I hope this helps.

Are you modifying the space cell to get 25A per VESC or do you have a different battery pack you’re using to get 25A per VESC?

Also, you mentioned you ran into issues even on small hills. Can you give any more details on small hills? My main route has at most 6% grade according to findhills (although it feels steeper in the real world).


Custom 18650 Battery (Pre-Build)
#12

I had issue on 7% grade hills, I make it up one and then by the second, it starts dying down. It sounds more like heat, but Chaka this it might be the amp limit, since I should be drawing more amps than 15 per motor to get up that hill.

About the space cell, I am in the process of all of this, hopefully I will finish in a few hours. But I am wiring around the bms. If I still have issues after this mod, then I will know where the problem is, which would be heat.

Either way, more amps is preferable.


#13

Glad to hear it man! I tried to be very thorough so far to help others out in the future…So far I am going to work with that enclosure and see what I can do. Ultimately, I will end up with a custom CNC wood enclosure most likely. As soon as I get the enclosure I can comment on if I will need to modify it at all, but I have a feeling that it will basically sit perfect on there given the boards shape. We shall see! Getting everything else this week or early next week hopefully! I believe the setup is rated for 30A continuous and 80A peak power.


#14

@Namasaki I see you’ve stepped up your game in choosing the music track for your video. Great choice!

This video has been really helpful. The terrain is pretty similar to what I’ll be dealing with.


#15

Can’t wait to see the board with the enclosure on it.

Based on everything I’m hearing, it seems like the flyweights and bantamweights are the only ones having success with 10S + Carvon’s Dual Hubs + Hills.

I guess when it comes down to it, I could either go on a major diet or jump up to 12S.

I’ve decided to go with @torqueboards 12S3P pack since I’m not a fan of cutting weight.


#16

Thanks, glad you like it.
It was my first attempt on a real video.


#17

heat is a problem, but it is not THE problem…

You have a set of motors that are designed to operate at a top speed of 106km/h (66mph) when powered by a fully charged 10S battery

If you are not operating them in their optimal RPM range they will be very inefficient, using more power than necessary & generating lots of heat

Drive trains should be designed to deliver a useable top speed. You want to try & keep the RPM in the optimal range to get optimal performance whilst reaching speeds you can manage. This is the problem with hub motors…

Example: I don’t like riding much faster than about 45km/h, mostly because it’s not safe in an urban environment. So I design my drive train to reach a max speed of approx 45km/h. When I am riding I ride at top speed when possible. When I approach a hill it’s at top speed. I have maximum RPM, maximum momentum, This is how electric skateboards (motors) like to work.

Let’s put it in perspective, The drive train I use for my systems
Motor pulley 15T
Wheel Pulley 36T
Motor 190kv
Battery Nominal Voltage 36v
Wheel 83mm
Why do I use this setup? Because top speed is around 45km/h…& that’s the speed I want to ride It makes sense. right?

Now If I swap the motor to a 450KV motor… the top speed is now 106km/h… it wouldn’t make sense, there is no advantage. There is not a single person on this forum that would agree that using a 450KV motor is a good idea.

The expected issues of using a 450kv motor on my skateboard

  1. Very poor starting performance
  2. Very poor hill climbing performance
  3. Very high current draw at low speed, High current peaks whenever loaded.
  4. Battery discharge problems, reduced life expectancy.
  5. ESC Problems.
  6. Overheating motors.

Increasing voltage
Using 12S battery on Carvon hubs won’t really solve any problems, It may actually stress your motors more. Your top speed now is 126km/h (79mph). The motor RPM when “at cruising speed” is now even lower than before. The higher voltage will simply make your motors want to spin faster, However, they will not necessarily be able to if they don’t have enough torque in that RPM range to reduce the load of the rider. The load on the motors & the torque output at low RPM is the problem Because torque is current you will need to pull more current until the load is reduced, which won’t really happen unless you reach the optimal (higher) RPM range, which won’t happen either. So your hill climbing performance probably won’t improve.

If anything, it might actually make sense to use lower voltage on Carvon HUBS. 6S is probably better suited. It may actually be more efficient.


#18

I don’t dispute your argument. but ride them and try. Even if the science doesn’t back us up, they feel really good. The larger wheels with a tad sponge to absorb some vibrations feel great. Check out this video to see a sneak peak of what they can do, including starting from a standstill. (btw, yes this is slow riding, I’m by no means pushing its speed limits)

At the end of the day, we need to get away from math and numbers, and just ride… That’s the only way to know, right?


#19

@evoheyax @onloop

For what it’s worth, I’m thinking about getting both the 12S3P and the space cell to test them out in the real world.

I’ll see which one works best for Jobby Lane and use the other to start a second build :smile:


#20

Most of the recent builds I’ve seen for Carvon V2 have used VESCs. Have you had any experience with the VESC as well?

How do you like the 12S ESC?

I might be wrong about this but I thought I was seeing people really like the Carvon V2 + VESC on FOC setting to reduce the amount of motor noise. Does your board run on the loud side?