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[Electric Cowboy]

Wrote up a clear article on how battery capacity is stupidly calculated today. Not the OEMs fault. Required by government bodies. Hopefully, the info helps us see the actual capacities of bikes. Also, it clears up the fake number stuff and shows consistency across OEMs, so the numbers are comparable at least...


https://www.electric.motorcycles/post/how-oems-calculate-battery-capacity-and-why-it-s-not-totally-their-fault-they-are-wrong

[DonTom]

Wrote up a clear article on how battery capacity is stupidly calculated today. Not the OEMs fault. Required by government bodies. Hopefully, the info helps us see the actual capacities of bikes. Also, it clears up the fake number stuff and shows consistency across OEMs, so the numbers are comparable at least...

I don't know why we should care if we are happy with our range on a "full" charge".

But to compare range can be a problem. I think only Tesla does it the right way with a chart  showing range at various speeds. A 310 mile M3 gets more than 400 miles range at 38 MPH at reasonable temps.

I would prefer the electric cycles to all do the same--have a chart, showing the temps done and on level ground, etc. Then compare.

But perhaps they can do something to compare what we really don't need to know, such a KWH standard. For an example, as I am sure you know that an amp hour is not always an amp hour when there is  a battery involved.  That used to be a problem with lead acid deep cycle batteries. They would give the AH rating where it is best, knowing perhaps nobody will be using it right at that current where it actually gives the  best AH. So they came up with a new number called "Reserve Capacity" to show the AH at the draw current level  where it is expected to be used.

Seems like both the range and KWHs will be an easy thing to standardize to stop all the BS.

-Don-  Auburn, CA

[Richard230]

At one time the Zero app showed the kWh remaining in the battery pack, which I thought was quite useful.  Based upon electrical usage shown on my Kill-A-Watt meter, it seemed fairly accurate, too.  But then one day that useful information disappeared from the app.  I wonder why?   

[Doug S]

I used to get upset about all this specsmanship too, but then the point you make in the end of your article finally sank in fully. Actual capacities aren't all that important. I mean, who really has a gut feel for what a kWh is anyhow? We know what a gallon of gas is, and have a feel for what a 12- versus a 15-gallon tank will do, but none of us really "get" kWh. The important thing is that the manufacturers are all doing the same rating by the same technique -- not surprisingly, they use the highest number. But that's okay. As long as we compare apples to apples, it doesn't really matter that what we're really buying is oranges.

They sell vehicles with apples, but it's all oranges underneath.

[NEW2elec]

To piggyback on Doug's and Dontom's points, I think the real question is what can the BIKE do with that kWh of power.  We know a gallon of gas, but that gallon goes much farther in a compact car than a cargo van, thus the MPG rating.
A heavy framed bike with liquid cooling and big tires and other add on features won't go as far as a lighter more streamlined bike.

A standard oval track with a standard rider weight (weights added to get a lite rider up to weight) at a set speed to give one standard miles per kWh rating.
 The buyer then knows this is likely the best range possible for the bike/battery combo and can subtract for the different variables from there.

[Electric Cowboy]

Also, I can see kWh just as we see gallons of gas. I can watch wh/mi just like mi/ga so for me it is important to know the right amount. But as you mentioned, that closing statement...

Also related to what the battery can deliver, when you get into the nuts and bolts we have to know the real capacity to understand how it works with the motor. As the information is all skewed up now, it is hard for most people to correlate things with factual info. When you post correlations based on bad numbers... people who know the science behind things question your ability to analyze what you see and can discredit you by saying "the numbers don't add up" and they are right... black magic you say. In-fact if we had all accurate numbers people could draw much better conclusions from anecdotal experience. Anecdotes atop inaccurate data though.. whew that's rough.

With all that said, given an understanding of the power a controller can output and a batteries true size, we can get a reasonable estimation, in our heads about how long it can ride, how badly it will heat/not heat, how long it can maintain peak power out excluding motor or controller thermal issues.

It's really important to understand the truth otherwise you may as well just stop thinking and believe anything anyone tells you just because. I don't subscribe to this is how people say it is, so why should I care about how it really is. I prefer the scientific approach, make assumptions based on accurate data and then learn from there, when the data is inaccurate, it makes working on things exponentially harder.

And once again, I am not faulting the OEMs for doing things with bad math, it is how they were told to do it by the governing bodies. I just want to put the info out there for anyone that cares to do some science.