Friday 12 July 2019

Mercane Wide Wheel: benefits to more power?


I've struggled with this idea for a while and decided that while I don't really need more power most of the time (and I doubt it will significantly influence travel times) that I just wanted to try it.

So while my Mercane Wide Wheel (500W) single motor is "perfectly sufficient" I decided that I'd try out the 1000W dual motor model (yep, one on each wheel).

In my explorations of the 500W model I've found that the cycle calculator I've been using suggests that by adding a few more watts I can get up the hills in my area with no slowdown. My calculations show this (I say mine, because I've had to tweak my parameters based on measurements):


Note: the 8% grade is actually about the standard for a wheel chair ramp. My hill is 9degrees which is 16%.  I picked 21kmh as this is pretty close to what I've found the speed limiter kicks in at anyway. Meaning that I could be going along a flat, and as I approach a hill it can increase to as steep as 8% and the scooters cruise control should just compensate by turning on more power.

In theory the scooter is able to provide 1,000W (sustainable, lets not go into peak), however as I've mentioned before as the battery voltage buckles under strain (batteries are not like regulated power supplies) down to 47V (which I commonly see under load and half way through the discharge cycle (see this post) that means that each motor will be able to deliver more like 450W to the ground (cos like nothing is 100% efficient right).

If I'm right then this means

  • the batteries will not be being hammered as hard on hills
  • flat roads will still be limited to 25kmh by the computer system
  • and down hills may be a bit less fast in peak speed due to the extra resistance of an extra motor.
So, all things being equal I'll be testing this tomorrow and will put in a video under this line to show findings.

Fingers Crossed :-)


Ok well I put my GoPro on and dragged it out of the house for its first start up. I had not run it (meaning fresh out of the box, over night charged) before this, so it was as fresh to me as it will be to you.

Just a warning, some "Aussie Guy" sort of language involved


Summary


  • Hill climbing power is WOW, the "pinch" up the last bit of my street before turning into the other street is 9 degrees (yes, degrees)
  • man, does it hammer that battery down if used unrestricted (wait for the comment about unlimited in the vid)
  • build quality is still excellent
  • change of surface coating materials may have it looking less beautiful with wear
  • observable torque steering, which makes for a surprise and can drag you off line on a corner when you "hit the power button"
  • a little lower clearance
  • a significantly heavier ... I notice its heavier but its still OK (just) for lifting in and out of the house. Car boot I dunno ... my wagon is fine thou
So, in short fuhhken great mate.

I went into the "hidden" settings and found that it had been set with speed restriction off, so I re-enabled it. My view is that this is not just a good and sane mode for operation (and legal compliance) but will enable you to get anything like decent distances out of your battery and (importantly) not fuck your battery as I see many have done to their scooters on Reddit by disabling exactly these features.

Disabling this is a bit like running Nitrous into your engine ... sure it'll surge like nothing on earth, but it'll be stuffed pretty soon.

HTH

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