I am curious what the best configuration is with the technology we have. I am not concerned with which motor or battery will be cheap/have longevity. I know its possible to build a 60mph+ board, but that is not what we are about. We want boards that are reliable and safe.
What I envision is to have a board that can accelerate up hills or have enough torque to maintain the speed on a 10% hill grade. Say, you reach max top speed and enter a hill that has a higher grade than 10%. Can the speed be maintained? How much torque is needed to reach top speed on a hill? What is the top speed for hills? The speed and torque should have a nice equilibrium. You don’t need enough torque to throw you from the board, but there needs to be enough to make it up any hill at a decent speed. For people like me, it would be good to know whats the best configuration to make it up hills because once you hit the top, there is no need for a motor.
So my question is what is the best configuration with the VESC? Highest top speed vs. torque to climb the steepest hills
From my research a 12S battery with a 198kv motor might be our max output with the VESC( I heard that the VESC won’t handle 12S with 200kv+). Is this best for top speed or torque? Would 11S with say, 250kv be better? Also, there is the factor of having one vs. two motors. Will two motors and two VESC allow us to build an insane 24S set-up?
I would also like to see what the best configuration is for the pre-built 10S3P or 10S4P batterys, since its lower than 12S. This is probably just an issue of higher and lower kv. What is the max/min for a reliable kv? Should we ever go above 300kv or lower than 150kv?
All this information will change when we test this in the real world. I personally live in a area with lots of hills, so torque should be a bit higher for people like me. Flat areas will need relatively little torque. This tool is great for calculating the max output for setups, but it doesn’t calculate torque or hills. Calculator Link:
I can’t tell you what the BEST setup is, but the dual 6355 motors (194kv…?) and 10s3p battery on the raptor dual can accelerate from a kick push to 20mph up the 15% grade next to my house. Gearing and wheel size also play a big factor. As does rider weight.
Hahaha no I’m just asking questions with my insufficient knowledge. I mostly just browse this forum, but I can see a reoccurring trend revolving around the question of kv and voltage. The only way to find these bits of information is to read every build thread and get each piece of information at a time. It would be nice to have a single thread so we can fully understand what all this is.
Standard knowledge: lower kv, higher torque.
So I have no idea what would be a kv that is too low. I am intending to build a quiver(multiple EBoards - I am also a skier so I have a different ski set-up for different snow conditions.) one for flat ground, one for hills, one for night rides etc…
Hahah … What you should do…is just get it done…not once…not twice … Not anything… Just do it…then break it …then build it …and when that settles in…build a new one…then break that shit…and build it…so on so fourth …
Get your base ride built …then you can build around it …Plus you’ll have some rides for your friends
The question you’re asking is the one all DIY’ers are trying to answer.
12S with 190kv motor seems to be the sweet spot. Check Vedder’s blog for a tutorial on how to select a motor for optimum performance.
Need more torque ? Go dual or go for a longer motor.
Alright, my intro into electricity 101 has officially begun. I have done some research just to double check the claims. I trust you guys, but my curiosity got the best of me I am taking the specs and breaking them down into bite sized chunks. I just got done looking at amps and volts.
VESC specs:
Voltage: 8V – 60V (Safe for 3S to 12S LiPo).
Current: Up to 240A for a couple of seconds or about 50A continuous depending on the temperature and air circulation around the PCB.
1S is what we all know as a lipo cell. Each cell contains (on average) 3.7Volts OR 4.2 Max Volts. 12S would be 3.7 x 12 = 44.4 OR 4.2 x 12 = 50.4 This shows that 12S is withing the safe range of 60V. Looking at the other ESC’s on the market showed me that they will only specify the safe number of cells. As in “Input Voltage: 4-14 cells li-XX or 12-42 Ni-MH/Ni-Cd battery” or “Power Supply: 2s~6s LiPo Battery”
The batteries then have the “C” and mAh ratings. You multiply these together to get your Amps. There are 1,000 mAh in a Ah. So a 5000mAh with a 10C rating is calculated like so: 5000mAh/1000 = 5Ah then, 5Ah x 10C = 50Ah. So by this it looks like a 5000mAh battery with 10C rating is the one to get.
Basics:
S (voltage) is (power) how fast you can go
A (amps) is (time) how far you can travel
I’m still waiting for a VESC haha so I have been slowly crafting my deck. I just got some acrylic paint for my design. It should be finished in the next few days. I’ll post it in my thread.
5000mAh is pretty low, but running a few of these batteries in series should double or triple the ride time? Increasing voltage should increase the power required, which might effect this claim…
Running batteries in series increases the voltage, while keeping the mAh the same. Running in parallel makes the inverse true.
I know this is going to sound like a sales pitch… but it’s just from my experience…
This is the best setup I have found.
10S | 190Kv | 83-90mm Wheels | 15-36 Motor/Wheel Pulley | Dual 6355 Motors | Max 50A Current limit
In terms of top speed, this configuration is 52km/h theoretical at full charge (~ 45km/h in reality)
In terms of hill climbing, this config eats hills… if you are a really heavy rider 100kg+ you might need dual diagonal 6374 motors…
What would I do to make it better?
Bigger (or more) motors, this is the answer to all questions about performance.
Bigger Battery, Bigger battery can output higher current for longer. Increase max current output up to approx 80A
Heat management systems, water or air. For motors, esc & maybe battery.
Wider Belts, Improved Torque transfer, to get all this power to the wheels!
Have your motor spinning up to max of around 8000-9000rpm for optimal performance.
What I wouldn’t do.
Higher voltage… Going 12S might (not enough info yet) introduce problems, especially with higher KV motors… For now, I am staying clear of that. ALSO: 11S is not a good number for battery assembly even numbers are better. So 10S is good.
Less gearing reduction, Never reduce reduction to increase speed. It will just increase current draw & overwork the motors. This is why HUB motors are difficult to perfect. Maximise Reduction & Custom KV motors is the best choice for your drive train… If you want more torque use a smaller wheel.
Ride faster than approx 45km/h… Any faster than this & wind resistance becomes a major problem & you get diminishing returns, basically you start converting energy to heat with minimal thrust. ALSO, any faster in urban environments is dangerous. Faster is ok on track day in controlled env.
Have you ever actually blown a VESC? I’m modifying a chinese device that came with a 60v lithium ion battery pack, and the VESC is rated for 60v in some descriptions, and 50v in others.
I am taking the specs and breaking them down into bite sized chunks. I just got done looking at amps and volts.