NO NO NO… If you have 2 identical motors running an efoil at the identical speed with the identical prop.
The only difference being that one is running 14S battery and the other is running a 12s battery, then the one running the 14S battery will be using less current at that same speed. If you still think it is different, you need to go consult the maths!
3 Likes
Measure it, at full throttle without active regulation, the 14s drive needs more power,
Which is also logical, because it wants to achieve more speed.
Stop trying to be right and actually go do the maths…
2 Likes
And learn to read … 
I hope you are talking about yourself there 
A motor has a set power. P = V x I. Therefore if you increase V, you need less I to get to that same power.
100 kV 40V = 4000 U / min
100kv 48 V = 4800
Assuming the same prop, the 2nd drive needs more power …
It is so and not otherwise!
that is right.
to return to the question 100kv 14 S vs 120 kv 12 S who is better. it would be purely mathematical for many of the 100kv. the hack at the thing is that you can not count everything. the less kv the more magnetic eddy losses can arise. to get around this, many motor manufacturers make more poles instead of making more turns to lower the kv.
1 Like
Some example here:
To reach 20km/h lets say you need 1200W and 3000rpm
With 120kv motor running at 12s you need 1200W / 44V=27A
With 100kv motor running at 14s you need
1200W / 52V = 23A
2 Likes
Kv x V = RPM
Kv x (P/I) = RPM
Therefore for the higher RPM you just demonstrated the current stays the exact same!!!
With 120KV on 14S you’ll also use 23A
1 Like
I know that but I did it for the question of someone earlier in this topic.
1 Like
Yeah it comes down to what you value. Would you rather have a slightly higher top speed, or a slightly more efficient system at the sacrifice of that top speed…
The power consumption is proportional to the 3rd power ( Potenz ) of the true rpm speed. that is an example. if the speed changes by 10%, the required drive power increases by about 30%. if the 120 kv is operated with the propeller x at 12 S, it will work. if you increase to 14 S, it will burn if the Propeller x itself is used as for 12 S. jetboardcolonge has already explicitly explained this.
1 Like
You compare different motors with I different voltage, with the same power, that’s clear that the current then goes down.
But don’t stop with the same engine …
1 Like
Thats true, if you run 120kv at 12s with a prop already on its maximum power than you can not run the same setup on 14s because you exceed its maximum power.
No one is running the 120Kv motor completely saturated at 12S, so this scenario never actually happens… The 120Kv motor can comfortably handle 14S and hence provide a higher top speed if required.
Also true, so thats why i run 120kv at 14s😉
I am running this motor with 12s12p 
I know there are many professionals here 
what I am writing now only applies to new beginners in e-foilsport. The engine setup must be designed so that it can deliver a very high thrust at full throttle. Why? very easily. before the board comes out of the water and you are foiling you need an incredible amount of energy. if you are a professional, you will quickly foil and the power requirement will decrease. but if you start as beginner you will need a lot of power in the water to start foiling. it is even more important if you drive a small wing and have 90 kg yourself. then the 5-7 more kp / h in the water with the board make a huge difference. this is a difference of 2 kilowatts that you need more to get out of the water. please take this into account in your considerations. it’s not just about how much power you need with foiling. who does not believe that has never been foiled
1 Like
Actually, I have taught many friends who never ever foiled before, some weighting about 90kg. They were able to get on the foil really fast (20meters maybe) with 50A motor at 12S (2400W).
The secret is the size of the board and surface of the foil.
- Too long board: you can’t change the angle of incidence of the foil easily. You COG shift will have only a limited effect, therefore it will take time and power to get flying.
- Too small is hard for beginners.
My board is 180cm x 75cm.
2 Likes