Mercane Widewheel battery and durability testing

So, about 5 months back I did this test on my Widewheel capacity and found that it performed pretty well and indeed pretty much within expectable specs as delivered. This is despite my regularly (audience gasp) charging it to 100% (because kiddies on reddit are so much more competent battery experts than the engineers who design BMS's and that's clearly going to destroy my battery).

Then again (because it was a fun way to spend half a day) last month took my Widewheel out on another long trip but as that has less hills (than this one) I wanted to do my torture test. Also I wanted to add another few km to the journey to see if it "still made it" and see what the outcome was with respect to voltages.

I thought I'd start not with the full trip, but with just the fastest parts of the down hill, which shows the sorts of speeds happening in more details

So pretty much what I experience in this older video:

As I mentioned this time I added a little extra distance to the trip (compared to the one last year) and so this is the new journey:

which is about 3 and a bit km longer back down off the mountain.

Data

I returned up my street (mild uphill) with about 44.5V showing on the handle bar and it recovered as soon as I stopped (because taking the load off) to 46.5V and a little later recovered to 46.9V. I discussed this discharge curve of batteries in this post about what I believe represents a good model of my own batteries (even though this is a cell) and I've adjusted the Y axis to reflect the series numbers of batteries in my pack.

On this occasion 431Wh was absorbed by the battery during charging, as opposed to the 410 of the last trip.

Considering this in gross terms (ignoring hills, winds and whatnot) this is 17.91Wh/km and on the previous run 19.7Wh/km. Given this run had less hills for the last additional 3.3km and that the previous above mentioned distance run (also not up a mountain) returned results of  16.4Wh/km that's about right.

So (depending on hills) about 15 minutes more riding would be expected before walking at this point, or about another 5 km remaining in the battery. This is essentially very close to what I recorded 5 months ago, and while I wasn't getting as detailed what I found nearly a year back too; which bodes well for "no measurable loss in battery" in the last year of operations.

Looking in details to the trip there and back (I zoomed in on the app for higher precision than seen in the summary) while I had a head wind all the way there which seemed to weaken somewhat as a lesser tail wind on the way back its interesting to see that despite the lower voltage the cruise control clearly does not "suck the battery hard" because similar speeds were seen both sides of the mountain

Worth noting that the climb on the way back is a down hill seen in reverse, so the beginning of the up hill and the end of the down hill were still making around 24kmh.

Consistency is good in this respect and the scoot does not feel significantly like its running out of grunt; which were one running on "unrestricted mode" not only would it not get this distance it most surely would feel more "limp" on the way back (from whatever trip it could make).

Discussion

Generally speaking the scooter gives pretty consistent consumption of energy over distances that are at the limits of its range. It has continued to do this for its life with me so far. Lacking a speedo on the Widewheel I can only estimate the distances done, however if I draw from the experience of my MX60 (which does have a speedo) it's done over 600km in the first month I owned it, and as I've had the Widewheel dual for 10 months now I think that well over 2000km is about the least it would be.

Meaning that its fair to conclude from these tests the following:

• the Widewheel is durable if maintained in at least a simple manner (adjust the brakes, keep an eye on things)
• the battery in the Widewheel (who gives a fuck what it is) is up to spec and also durable
• fully charging the battery would seem to have no observable influence on the batterys ability to perform over that year of hard work (and I don't fully charge it on every trip, I follow the charge it when needed approach)
• one can estimate that "flat" routes will use 17Wh per km and steep routes (where you'll come back down) may use about 19Wh/km. Using this and knowing the Wh of the battery and adding in a little common sense about the difficult nature of the last few Wh contained in the battery you can plan trips reliably.

Hope this helps

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PS I redid this test on the 10th of April 2021 and got similar results

1. return voltage was 46.4V
2. charge required 406Wh

Points to consider on this

• I went up to Johns (adding a couple of km)
• on the way up to Queen Mary I had a tail wind (which would have assisted somewhat)
• on the way down (of course) I had a head wind, but for the steepest parts the speeds were still sufficiently high that back EMF would almost fully negate any additional power demands for that