Mercane Dual motor underbelly

being one to always like to look under the covers (as well as check all the screws) I decided this afternoon to to pull the cover off the battery pack on the Mercane and have a look. Compared to the single motor its quite "pregnant" under there. Basically everything below the red line is unique to the bigger battery system of the dual motor.

Its certainly made the whole thing heavier, with my scales suggesting that the weight is actually more like 23kg. Interestingly it has a front rear weight distribution which puts 14kg on the front and 9kg on the back (bathroom scales under each wheel and confirmed with my digital luggage scales and also with my holding it and getting onto the bathroom scales). Update: my single motor variant is 11kg front.

Interesting.

So what's under the cover?

In this shot we see that the battery runs the full length of the available tray, as well as the wonderful webbing cast that strengthen that entire platform and the controllers.

plural you say?

Yes, two controllers, stacked one atop the other and thus hanging down lower than the battery pack.

as well as seeing where the plastic belly pan screws into we see the location two controllers. Which is interesting and confirms my suspicion that the way the dual motor version was implemented was to just double the controllers and bung a back wheel on the front with its own controller. Simple and quick upgrade, run some more wires and voilla. Indeed that cable that powers the front wheel jutting out of the goose-neck at the front sticks out like an after thought to me when I think of it.

The basic maths on the controller is that being rated at 15 Amps it can handle 720W which is more than the peak draw of each motor, so there is built in margins there, which is nice.

Now its interesting to look at these controllers and observe that they are passively cooled (fins give that away), given how much heat controllers need to shed (from switching as much power as they do) is this a bad thing in an enclosed and sealed case? Perhaps, lets recall that the Wide Wheel has its origins in a indigogo campaign (link here) and when it was envisaged it was a single motor design.

Now owners of Mercanes may have noticed this set of 4 bolts directly above the controller ...

I understand that this is for a seat (I'd feel shame) ... none the less mounting the controllers up against the chassis looks to me a very tidy way of making use of that big cast aluminium frame as a heat sink. Cunning and well designed!

So it would appear that the original single wheel version planned for this from the outset, but the dual motor version just whacks that controller onto the bottom of (not a big heat sink) but the other side of a hot controller.

I'd hope that this was tested before being done, but somehow I have some reservations. Indeed I've seen examples of burnt out controllers on the dual wheel on YouTube already (by perplexed non technical owners).

I dunno ...

Anyway, moving up front we see more clearly that lovely webbed cast plate which is the main chassis of the scooter. It actually looks fantastically well designed and made. Looking at the lip around the bottom of the chassis you can see that the belly pan fits snugly into that. However also you can see that any water throw up from the front wheel will be likely to gradually work its way into that crack and down into the belly pan (where there is no way out). This is why I put duct tape over that join to prevent such (as I've owned old English cars in the past ;-)  (post on that here)

as well we can see the underside of the XT60 charging port (so clearly no problem if a little moisture found its way in there past the plugs and cover)as well as one of the belly pan mounts and holy moses look at the bracing around where the goose-neck mounts.

I'd have to pull it apart to see, but it looks like the goose-neck goes down into there and mounts somehow. I'm keen to pull that apart and look (especially after seeing a few Zero's bite the dust exactly due to insufficient engineering there (this is a shot from the internet):

as an engineering sort of guy that even looks inadequate before it broke. Sure, the front part looks solid, but you know what they say about the weakest link in a chain right?

Round up

Well that about rounds up what I've got to present tonight. The Mercane chassis looks great, I love the way the controller uses the chassis as a heat sink, but I have my reservations about the piggybacking of the second controller down there.

Then theres the weight ... its a lot heavier to heft around than my Single motor version ... which to me is shaping up as the sweet spot of the design (and indeed closer to the original conception of the designers. As I see it the original concept of the single engine 8.8Ah battery is not only sufficient (as I've already found) but robust.

I'm starting to feel like the move to dual wheel was more about being seen as "not competitive" in a market which is more interested in bling and "hot looks" than in good robust transport.

So basically I'm saying I'm thinking of seeing if I can send the dual motor one back and sticking with the single ... but then again, maybe I'll just keep it longer. Besides, its convenient to have two right now.