Since the beginning, voltage has been on the rise in electric skateboards. From what started as low voltage, then standardised as 10s Li-Ion, we are now at a turning point where major brands are fighting to push boundaries up to 12s and further. What is the point you might ask?
Well its not about more power. It's a little deeper than that, and we are diving in.
Following on from our previous talk, we know so far that motor Kv doesn't affect performance much as long as the correct power is applied.
Therefore, we know that increasing our voltage and lowering a Kv is not giving a greater final power. Of course, the motor is not experiencing a benefit in thermal performance either, with the electrical conductive mass being unchanged and the resistance increasing with lower Kv. Then what is happening?
We have to see the big picture; There are more variables than just how much power is going down to the wheels. How long can that power be maintained? Cost? Charge time? Form factor? Overall system efficiency? All of these factors combined make or break a good system, and increased voltage is one of the keys to ticking all of the boxes bar one.
Back to basics;
- Voltage and Amperes make power.
- Conductive masses resist Amperes to varying degrees, which generates heat.
Naturally, if there is less Amperes, there will be less heat. To make a desired power, we must increase the voltage. This process generally improves system efficiency and is the same principle that power grids utilise, as well as most high performance electric vehicles; like the 1000V Formula E systems. Generating less heat will lead to better reliability, more useable capacity from a pack and maintaining power for a longer consistent time before overheating.
The current VESC based offerings are on the trend of higher voltage, and the overall size and ampere throughput is staying closely the same. This means that higher power motor controllers in the same or similar size is a possibility, and is mostly due to higher voltage. This is important for electric skateboards, where the ideal size is a limited range and power needs are ever-growing. A side effect is that the wiring and connections required don't need to change much, if at all. Again reducing the size of a high power system.
Another important point of higher voltage involves the charging period and the port used. Once again, the connection required doesn't have to increase to huge proportions while allowing a lot of charge power. Subsequently, the charge time can be decreased dramatically with the popular small charge ports. This is particularly effective for racing applications, where charge intervals need to be fast.
One of the few real drawbacks of a higher voltage system is cost, and this is directly why most consumer products are taking so long to get there. In some cases, it just isn't economically viable to sell something so expensive. We believe more in innovation and pushing boundaries than we do in profit margins alone, and I think that is reflected in our current projects with high-voltage performance in mind.
Who knows what the future holds, but one thing is for certain, it can only go up.
- High voltage is a way to gain more power in a smaller size than equivalent high Ampere systems.
- High voltage systems are expensive, and not always viable.
- This is one way to manage thermal performance of the system as a whole, not the motors alone.
- Faster charging is good for the soul.
This is subjective, simplified information and is open to error.