CONFUSING CHARGE RATES

Electric vehicles come with a new set of terminology, it's just the reality of the different technology. Vehicle range is still vehicle range - measured in distance, but referencing the battery capacity to provide that distance can be confusing. Kilowatt-hours is a new metric for many, and we're used to measuring our gas tanks in fractions, not percentages. Electric vehicles are closer to your cell phone in some regards than combustion engine vehicles.

Charging is a whole new concept with no real equivalent in the traditional combustion engine world. You pump a liquid into a tank until it's full - that's very easy to understand. But electric vehicles “fill up” at vastly different speeds depending on different factors, many of which aren't immediately obvious. Electric vehicles specify their DC fast-charge rates in a wide variety of ways. Some manufacturers specify the amount of time from 0% - 80% charge, some specify different percentage ranges, and some specify miles gained over time. At Atlis, we feel this is the wrong way to go because it is confusing to customers. One vehicle can add 200 miles in 20 minutes, another vehicle can add 150 miles in 15 minutes, others 0%-80% in 40 minutes, etc. - what does it all mean? How do you compare them? We want to say that we can "fully recharge" from dead empty to "100%" full, the rated range of the vehicle, in 15 minutes. That's clear.

You can see in this chart below a few examples of different charging claims by manufacturers, pulled directly from their websites* at the time of this writing.




You should note that none of the manufacturer specified numbers ever represent a full charge to the rated range, only the maximum possible charge rate under the most ideal conditions, which means the battery is at a low state-of-charge, using a high-power charger (HPC), and the battery is at the correct temperature - not too hot and not too cold. If any of these variables change, you will see slower charge speeds. The reason they avoid a specification approaching full-charge is that of something publicly called charge “taper,” the constant voltage portion of the battery charging curve, which causes the charge rate to slow down as the battery gets closer to being fully charged. We're not going to dive into the details of tapering, but instead, we want to show how these charge rates and state-of-charge percentages are marketed, and how it affects you, the consumer.

State-of-Charge (SOC) is represented in percent and is also misleading. “Percent of what?” is the most important question to ask - when dealing with battery capacity most battery management systems (BMS) prevent access to the entire rated capacity. What you're really driving on is the “available capacity” that the BMS allows the vehicle drive systems to access, which is the total capacity minus a top and bottom buffer. These buffers are there for a variety of reasons, and vary in size between vehicles, and are rarely specified. “100%” isn't really 100%, it's really just a made-up voltage that the cell designer and manufacturer selected as the best balance of performance and longevity. The percentage itself holds little value.

As such, Atlis is trying to move away from percentages. What's meaningful to you as a driver is how far you can go, and how quickly you can do it again. The reality is a diesel truck can go 400 or 500 miles on a tank and not be bothered and can do it again 10 minutes later after filling up. We're looking to take the toughest-of-tough truck enthusiasts head-on, many of who haven't experienced and primarily don't accept the compromises within the EV world. Atlis is not going to be able to compete in the truck marketplace with a rating of 200 miles gained in 30 minutes. It's a compromise, one that contractors won't understand - they just want to go about doing their job.

EV enthusiasts often make statements like "it's good enough for most people" - which is true, but we at Atlis are not trying to solve the problem of "most people" - we're trying to solve the corner-case scenarios that the EV world has ignored. Some people need to drive hundreds of miles in a day while towing equipment. We want them to be able to do what they do now, but also experience the benefits of an electric powertrain.

We're not making excuses, we're making solutions.

* References https://www.tesla.com/modelx https://www.jaguarusa.com/all-models/i-pace/electric-vehicles/index.html https://www.audiusa.com/models/audi-e-tron https://www.mbusa.com/mercedes/future/model/model-2020_Mercedes_Benz_EQC https://www.porsche.com/microsite/mission-e/international.aspx#/charging https://www.chevrolet.com/electric/bolt-ev-electric-car


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