Charging Time Differences

  • Thread starter Thread starter Clamps
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Clamps

Clamps

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I watched a video today and it really put into perspective charge times on a longish road trip. The videos (there were two made, one from each drivers perspective) were a rebuttal to a NYT’s opinion piece. One driver had a Model 3 and the other a Bolt and while I know the Tesla has a faster charging time it really hammers home the difference in a practical application like this versus numbers and data. The short of it was the Tesla used one hour of charge time while the Bolt needed two hours and 45 minutes for almost the same journey of LA to Vegas and back. In fact the Tesla owner stated that he could have shaved ten minutes off his time.

I believe this is a pre 2020 Bolt and even though they both max at 50kw the newest Bolt has a better curve before flattening out the charge rate. Still that difference is remarkable. Would have loved it if a Kona were part of the mix.

Here is the video if you are curious:
 
Were you referencing the 2013 article described in this Tesla response: https://www.tesla.com/blog/most-peculiar-test-drive

There are two design approaches to charging: constant rate, and peak rate. This InsideEV article covers many constant rate chargers: https://insideevs.com/news/338777/lets-look-at-fast-charging-curves-for-popular-electric-cars/

charging-with-a-bmw-i3-source-fastned.jpg

I've shown the BMW i3 charge curve which is limited to a maximum of 50 kW and gradually ramps up. The current is held current but the power increases as the battery voltage increases.

In contrast, this is an earlier charge profile for our Std Rng Plus Model 3:
250_kW_charge.webp

Our Tesla has a peak charge that occurs in the beginning and gradually tapers off. The green dashed line and right side axis, miles, shows how fast it added range. My Std Rng Plus Model 3 is the smallest battery Tesla, ~50-55 kWh. The larger battery Model 3, ~75 kWh, can reach 250 kW peak charge rate but they also need a few more kWh/mi.

You'll notice my X-axis is in minutes while others prefer % SOC. They are welcome to their choice. My use of charging time is based upon a need to know how much time I will be spending at a charger for block-to-block speed planning.

Bob Wilson
 
I think the videos were addressing an article from last year, June 2019. Personally I wasn’t put out by the negative press that initiated the youtubers response, I was just impressed at the Tesla’s charging speed compared to a Bolt. I knew it was substantially faster but to see it applied in a practical application was very revealing.
 
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