We are proud to announce a new product that will suite the eFoil DIY builders very well.
The VESC 6 has been used for some eFoil builds already but our customers demanded more peak power to get the board out of the water quicker. When updating the VESC 6 to the latest MarkVI standard, we managed to get 12 Fets into the same for factor and increase the peak power handling quite a bit.
This design can measure currents up to 210A reliably and push up to 160A peak with a 70A continuous when no additional cooling is applied (sitting on the desk at room temperature).
With these specs it should be the perfect match for hydrofoils, especially if you manage to screw it to some additional thermal mass.
We have a 16S version lined up for next year. I’m not convinced that going beyond 12S is increasing the performance/efficiency a lot. Typically this makes more sense for hub motors on e-bikes where the copper cables are long and thin. A foil should be trimmed to be efficient and run on maybe 40-50A continuous. There is no big gain from stepping up the voltage to 14S. You would decrease the motor KV if you go up in voltage and then the motor has a higher resistance. So you would push less amps but the heat build up is the same because of the increased motor resistance. The only reason to go beyond 12S is the cable from the ESC to the motor. At 16S it can be a bit thinner. 14S is not worth the extra cost.
But 16S is also a lot more dangerous in combination with water…
14S is very much worth it! Ask any of the guys that have foiled at both 12S and 14S. There’s zero reason to decrease the KV if you go up to 14S. With the same motor it simply provides a slight increase in Torque (allowing a higher pitch prop) and a 16% increase in RPM at the prop for a direct drive efoil. That’s a massive advantage.
When you compare systems, you have to adjust the motor accordingly. Obviously you would wind the motor differently if you want to achieve the same RPM at a lower voltage. Your motor simply needs 17% higher KV value if you step down from 14S to 12S. Otherwise you compare apples to oranges… Running the same motor at two different voltages will for sure give you a different experience. But that is no hint that the higher voltage is better or performs better. It only tells you that your chosen motor puts out a higher RPM with a higher voltage. Torque is only proportional to the amps and totally independent from voltage. Copper losses are proportional to the square of the torque produced. This is why electric motors rather spin fast and produce less torque if you want a good efficiency.
The problem is you are assuming that guys change the motor which they don’t because of the cost.
Most DIY efoil builders will buy one of 2 motors, both which can handle 14S. While they may start at 12S, many eventually move to 14S by simply adding extra cells which is a lot cheaper than getting a new motor and speed controller. Also motor torque at any given speed is proportional to the square of the applied voltage. Simply put, with the current generation of efoil motors you going to achieve higher torque and speed at 14S…
If you want a bit more top speed out of the same motor you can also add some field weakening and gain the extra RPM you need for top speed. Filed weakening allows you to operate the motor above the max RPM defined by it’s KV value. You can inject some current into the D-Axis and increase the RPM further.
Motor Settings >> FOC >> Field Weakening >> Filed weakening Current Max
For example add 8 A here.
It is not as good as adding KV to the motor but an option for adding top speed at no extra cost. No extra cells, no new motor, no new ESC. So if you have a 12S System or a certain motor already I would personally start to play with the setting first and see how well it goes.
Torque at a given ERPM is dependent on current only. You simply need to push more current to get more torque out of the same KV motor. Voltage plays no role here.
Torque is proportional to current / KV. So for a given KV you adjust the torque by the current you push.
In most cases battery amps are way lower than motor currents. It depends on duty cycle…
If you wan to water cool, you can screw the VESC 6 HP onto a water cooled plate.
This is not specifically designed for foils, but well suited if you run an energy efficient foil.
Peak motor max current is 160A and spikes can go as high as 220A.
We have some customers using the regular VESC 6 in a hydrofoil.
With this one they would have plenty extra punch.
If you have a foil that draws around 60-70A continuous during your average ride, this unit is pretty bang on power wise. Enough headroom to get out of the water and enough headroom for some speed runs.
