Sunday, 6 October 2019

Dual vs Single: power proving a theory (or two)

When I bought the Mercane dual motor Wide Wheel it was also to clarify a point.

I knew (of course) that the 1000W (pair of) motor(s) would provide much better hill climbing (that much was obvious), and my use of a calculator (explored in this post) made that an expected outcome. Experiencing it was actually more fun than I'd expected.

However what I was unsure about was this: did more battery translate to different range between the two scooters when there was double the motor? Given that there were a few considerations to make:

  • twice the torque on hills must use more power
  • however at fixed speed (governed by the speed limiter) power needs would be more or less the same between the scoots on a flat path
  • the dual will have a bit more rolling resistance (which I've measured as being about double) due to the additional motor
  • 422Wh battery on the Single and 633Wh on the Dual = 50% more battery on the Dual but 100% more power


The answer it seems is that having more power available does not use that much more battery, it actually gives a greater range. and this has been emerging as a picture in the fact that I've been able to go places, which are hilly, that I couldn't do on the single.

Hypothesis Clarified

Yesterday I went for a scoot with a mate and he took the single and I took the dual. The route is below:


The red arrow is where the single motor ran out on the way back.We walked along for a while (about another 1.5 km and then decided to do a "tow" where he balanced on the scooter and put a hand on my shoulder and I towed him. Of course I had to accelerate slowly and we found that a speed of about 10kmh was pretty ideal.

So this means that for the remaining (about) 2km the dual motor pulled him and me. I can say from the pressure on my shoulder that a few kilograms of force was needed to get him rolling and while of course less a few kilograms needed to keep him rolling.

My dual motor scoot was still at 49V when we got back to the car.

He had a great time (as did I) and the entire thing was a great fun afternoon with a bit of "team building" type cooperative behaviour tossed in for good measure.

Take outs:

  • The Dual motors is amply compensated for by the 50% increase in battery.
  • My friend had never scooted nor used a skateboard, but done a fair bit of rollerblading, so had the basic intuition for good balance. After the basic safety introduction (braking and stance) I moved into teaching him that balance is through your feet, and that if you feel wobbles in the bars its because you aren't balanced on your feet.
  • He picked that up pretty fast and within a few km was exporing which foot was better back and agreed that while one is naturally dominant that being comfortable with both is important
  • After he'd had 10 km on the Single I gave him the dual and he was impressed by the extra power
  • People love these things almost immediately and find that doing trips on them is just great fun.
The second theory I proved is that basic instruction makes a huge difference in learning curve and confidence levels (and growth of them) in a novice. There probably should be courses for scooting.

Happy Scooting

No comments: