Best charging curve I've seen yet from a 100kW DCFC - Chevy Bolt EV Forum
User Tag List

 6Likes
  • 6 Post By wesley
 
Thread Tools
post #1 of 7 (permalink) Old 05-21-2019, 08:16 AM Thread Starter
Senior Member
 
wesley's Avatar
 
Join Date: Jul 2018
Location: Korea
Posts: 224
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 108 Post(s)
Garage
(Thread Starter)
Best charging curve I've seen yet from a 100kW DCFC





I think I mentioned it in another thread, but there's a free (as in beer) 100kW DCFC near my home that I've been using for the past 3 months or so. It'll turn into a paid station soon, but not before getting these neat charging graphs out of it. Charger doing 150A from the get-go was something I hadn't witnessed before, but apparently it can happen with the right battery temperature - around 25 to 26C.

I've made some analysis in my blog post, but I think much of the stuff are self-explanatory. We have the voltage creeping up, the current staggering down in steps (50% - 67% - 83% - 92% - 98%), the battery heating up at 150A charging and then subsequently cooling thanks to a lower ambient temperature, and the SoC curves doing a nice slope against the charging time.
Attached Thumbnails
Click image for larger version

Name:	Bolt_EV_Charging_Data_1.png
Views:	287
Size:	61.8 KB
ID:	25427   Click image for larger version

Name:	Bolt_EV_Charging_Data_2.png
Views:	183
Size:	68.2 KB
ID:	25429  

Range Anxiety?
wesley is offline  
Sponsored Links
Advertisement
 
post #2 of 7 (permalink) Old 05-21-2019, 03:03 PM
Senior Member
 
Join Date: Feb 2018
Posts: 1,165
Mentioned: 17 Post(s)
Tagged: 1 Thread(s)
Quoted: 830 Post(s)
Interesting.

In the video below (also max speed charging), the Bolt tapers at 70%, whereas in your graph (and some other graphs too) it tapers at 67%. I wonder what governs this...

Vertiformed is online now  
post #3 of 7 (permalink) Old 05-21-2019, 04:08 PM
Senior Member
 
Join Date: Oct 2017
Posts: 2,173
Mentioned: 15 Post(s)
Tagged: 1 Thread(s)
Quoted: 784 Post(s)
Quote:
Originally Posted by Vertiformed View Post
Interesting.

In the video below (also max speed charging), the Bolt tapers at 70%, whereas in your graph (and some other graphs too) it tapers at 67%. I wonder what governs this...
Looks like the tapering occurs right when the battery temp hits 34C. Guessing this would be the variable that triggers the tapering.
XJ12 is offline  
Sponsored Links
Advertisement
 
post #4 of 7 (permalink) Old 07-19-2019, 12:01 PM
Junior Member
 
pfrost's Avatar
 
Join Date: Jan 2019
Posts: 28
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 7 Post(s)
Garage
Quote:
Originally Posted by Vertiformed View Post

In the video below (also max speed charging), the Bolt tapers at 70%, whereas in your graph (and some other graphs too) it tapers at 67%. I wonder what governs this...
I'm curious about this as well. All the videos I've seen of 150A DCFC have shown tapering at 55% and not at 50%. Maybe it's a temp thing, as stated? But that would only explain the taper at 50%, not the 67% (instead of 71%). Maybe conditions were not optimal?
pfrost is offline  
post #5 of 7 (permalink) Old Yesterday, 10:31 AM
Member
 
Join Date: Dec 2016
Posts: 95
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 58 Post(s)
Quote:
Originally Posted by XJ12 View Post
Looks like the tapering occurs right when the battery temp hits 34C. Guessing this would be the variable that triggers the tapering.
I trust all of the data on that screen except for the battery SOC percentage. It seemed to read a bit high, as noted in the accompanying article linked in the YouTube video description.

This was not a final product version of the software and this screen was designed for test engineers. The SOC may have been calculated by the charger dispenser instead of displaying the value supplied by the car. I donít know.
Jeff N is offline  
post #6 of 7 (permalink) Old Yesterday, 08:14 PM
Senior Member
 
Join Date: Apr 2018
Location: Osceola Arkansas
Posts: 414
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 257 Post(s)
My Bolt has always tapered at around 50% and 67% on DCFC, and I am jealous of those who get to 55% and 70+% before tapering. I would think it was a temperature issue, but Eric (NewsCoulomb) drives his car pretty hard, so I doubt his battery pack is nice and cool when he starts a charge, and he gets the later taper points than me on a normal basis.

Keith
Fivedoor is online now  
post #7 of 7 (permalink) Old Today, 12:10 AM
Senior Member
 
Join Date: Feb 2018
Posts: 1,165
Mentioned: 17 Post(s)
Tagged: 1 Thread(s)
Quoted: 830 Post(s)
Quote:
Originally Posted by Jeff N View Post
I trust all of the data on that screen except for the battery SOC percentage. It seemed to read a bit high, as noted in the accompanying article linked in the YouTube video description.

This was not a final product version of the software and this screen was designed for test engineers. The SOC may have been calculated by the charger dispenser instead of displaying the value supplied by the car. I donít know.
The battery SoC is communicated by the car to the station. Even if it were possible to use other information supplied by the car (e.g., voltage demanded) to try to guess SoC, there would be zero reason to do so when the correct information is already provided as part of the protocol.
Vertiformed is online now  
Reply

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off

 
For the best viewing experience please update your browser to Google Chrome