Multiple DC Quick Charges did get a Hot Battery for this guy

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TonyWilliams

Well-known member
Joined
Feb 19, 2011
Messages
10,107
Location
Vista, California USA
This is a picture that I stole from a LEAF driver who drove the inaugural Oregon Electric Highway yesterday, in mild March (jacket wearing) weather. After multiple quick charges to 80-90% every 25 miles, this is the result. The number 9 temperature bar is over 52.5C/126F.

Yes Virginia, there is a hot battery in there.


d4b5d969.jpg



The trip down:

* Leav Corvallis: 2pm
* Arrive Eugene: 3pm, leave 5:20pm - 47.8 miles, 13.1kWh
* Cottage Grove: 6pm, leave 7pm - 25.2 miles, 7.8kWh
* Rice Hill: 7:26pm, leave 7:45pm - 26.7 miles, 9.2kWh
* Roseburg: 8:17pm, leave 8:35pm - 23.9 miles, 7.5kWh
* Canyonville: 9:10pm, leave 9:34 - 25.6 miles, 8.7kWh
* Wolf Creek: 10:05pm, leave 10:26pm - 23.0 miles, 8.7kWh
* Grants Pass: 10:51pm, leave 11:28pm - 18.2 miles, 5.8kWh
* Ashland: 12:24am - 45.0 miles, 14.5kWh

Total: 75kWh

The trip back:

* Leave Ashland: 8:32am
* Ashland: 9:10am, leave 10:08am - 30 miles, 8.6kWh
* Central Point: 10:30am?, leave 12:30pm? - 18.4 miles, 4.3kWh
* Grants Pass: 12:49pm, leave 3:42pm - 25.4 miles, 6.4kWh (10.7 total from Ashland, vs 14.5 to go the other way)
* Wolf Creek: 4:03pm, leave 5:06pm - 18.4 miles, 6.0kWh (vs 5.8kWh)
* Canyonville: 5:32pm, leave 5:49pm - 23.2 miles, 6.5kWh (vs 8.7kWh)
* Roseburg: 6:16pm, leave 6:42pm - 25.3 miles, 7.1kWh (vs 8.7kWh)
* Rice Hill: 7:09pm, leave 7:29pm - 23.2 miles, 7.1kWh (vs 7.5kWh)
* Cottage Grove: 8:01pm, leave 8:57pm - 26.3 miles, 7.2kWh (vs 9.2kWh)
* Corvallis: 10:16pm - 64.4 miles, 14.3kWh (vs total of 20.9kWh and 73 miles)

Total: 67.5kWh
Grand total: 142.5kWh

http://media.batie.org/wceh/" onclick="window.open(this.href);return false;
 
I wonder how that will show up in the battery report? I suspect that is exactly the behavior that Nissan was referring to when they said to avoid frequent quick charging....
 
I'd love to see the data that Nissan allegedly accumulated from the Arizona desert. There is NO WAY that a car on the hottest day in Phoenix will be able to quick charge very much, if at all.
 
TonyWilliams said:
....After multiple quick charges to 80-90% every 25 miles, this is the result. The number eight temperature bar is over 50C/122F....

d4b5d969.jpg

How many charges, over how many miles, in how much time?

Did the driver happen to notice how long it took battery temp to return to ambient, 4 or 5 bars,
after completing the trip?
 
edatoakrun said:
TonyWilliams said:
....After multiple quick charges to 80-90% every 25 miles, this is the result. The number eight temperature bar is over 50C/122F....
How many charges, over how many miles, in how much time?
Fair albeit argumentative questions. It will be tough to find out all the relevant information without access to QC, and proper instrumentation. I can assure you however that some of this information could have been gleaned from LEAF tour and motorshow photos. Generally, you would see cars with 7 and 8 temp bars there. Highly unusual, considering our collective experience last year. Nissan presumably uses QC liberally at these events. Also, Nissan's statement that it's OK to QC if the battery temp gauge is not in the red zone, would imply that heat development is a key factor. There are a few people with direct QC experience out there, and perhaps they can chime in.
 
What is the problem? It is not in the red zone. You cannot extrapolate that it would be if the outside temperature were higher. When I studied engineering we were taught never to extrapolate.
 
TonyWilliams said:
After multiple quick charges to 80-90% every 25 miles, this is the result.
While I can see making a point of charging at each station for an inaugural run, I don't understand why he would have charged to 80-90% every 25 miles. Undoubtedly there is more battery warming when repeatedly quick charging at higher SOCs. My guess is that his battery would have been happier if he had stopped each charge at, say, 50-60% if he only intended to drive 25 miles to the next charger.

These Dutch guys drove 780 miles in 24 hours by repeatedly quick charging, and apparently did not have battery temperature issues. But they were driving more miles between charges, and starting each charge at a lower SOC.
 
I'm wondering if the occasional hot battery is good for it, or bad for it.

With about 30% of the lithium ions irreversibly bound to the graphite defects in the battery, would warming help shed some of those?

Or does the high temperature produce more graphite defects where ions can go and bind irreversibly?

There are a lot of ways these batteries cold be better (e.g. better graphite, maybe SiCO as a replacement,...), but I wonder how well these things are understood.
 
If you drive "like you stole the car" you might use 60% in 25 miles, and then immediately QC from 20% to 80%, getting back on the road immediately.

It sure would be nice to have a continuous Log of this entire trip.
 
Its not exactly warm here (Seattle), so if Oregon weather is somewhat like ours, I wonder
why the battery did not cool down a bit between stops...Or maybe he was going very fast between charges?
 
Isn't quick charging every 25 miles the equivalent of drinking 2,500 cans of diet coke every day and wondering about your cancer risk?

In other words, not something I'm ever going to do....

It wouldn't have hurt to have a couple of cars to demo the chain of 8 quick chargers and stop at every other station...
 
BRBarian said:
I wonder how well these things are understood.
Nissan has been working with Lithium Ion since the Altra EV. http://www.eanet.com/ev1-club/archive/981017/981017.htm Scroll down to Nissan Presentation.

Li-Ion cells are currently very expensive, but Nissan is investigating replacing the cobalt in the batteries with manganese or aluminum to reduce cost.
- 1998

That Altra had a 30.2 KWH battery! Wonder how much it cost then... :roll:

Edit: Look at the "Mange Charge Program Report" about how quick charging was first done, with a liquid cooled inductive paddle! :eek:
 
Desertstraw said:
What is the problem? It is not in the red zone. You cannot extrapolate that it would be if the outside temperature were higher. When I studied engineering we were taught never to extrapolate.


It is probably wise to now reexamine the temperature gauge:

LEAF Batt Temp
Segments Degrees C (F)
12 60.         (140)
11 57.5     (135.5)
10 55           (131)
9 52.5     (126.5)
8 50          (122)
7 36.8     (98.2)
6 23.5     (74.3)
5 10.3      (50.5)
4 -3          (26.6)
3 -6           (21.2
2 -9           (15.8)
1 -12        (10.4)
0 -15          (5)

Temperature bar number 9 is 52.5C, and each bar above it is only 2.5C. So, the difference between 8 and 12 combined is less than all of just bar 7 by a significant margin.

In a more conventional "engineering" thinking, temp bars 8-12 would be one bar, if 4-7 are each a value over 5 times the value of 8 -12 individually.

It could have hit a red bar quite easily I would guess in higher ambient temps. It was less than 5C from popping red.
 
abasile said:
TonyWilliams said:
After multiple quick charges to 80-90% every 25 miles, this is the result.
While I can see making a point of charging at each station for an inaugural run, I don't understand why he would have charged to 80-90% every 25 miles. Undoubtedly there is more battery warming when repeatedly quick charging at higher SOCs. My guess is that his battery would have been happier if he had stopped each charge at, say, 50-60% if he only intended to drive 25 miles to the next charger.

These Dutch guys drove 780 miles in 24 hours by repeatedly quick charging, and apparently did not have battery temperature issues. But they were driving more miles between charges, and starting each charge at a lower SOC.

I watched their video some time ago when it came out on utube. They never talked about the battery temperature so we can't be sure how hot it got. I was really disappointed that they didn't share that information.
 
Luft said:
I was really disappointed that they didn't share that information.
Good point, me too! But then, you have to keep in mind that these guys work for Epyon, and they wouldn't want to show anything that would discourage QC use. Short of the vehicle refusing to charge or malfunctioning, there was simply no reason to get into the nitty gritty, quite the opposite.
 
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