Chevy Bolt EV Forum banner

1 - 11 of 11 Posts

·
Registered
Joined
·
751 Posts
Discussion Starter #1
There's been a big temperature swing last week in my country, which is probably related to that extreme cold that hit Texas at a similar timeframe. I made a couple of very similar long-distance trips on both the day when it was the coldest, and when it got unusually warm.

About 80% of each of the entire trip was made on the expressways, with speed pegged at 100 km/h (62 mph) on the dashboard. I was not using any heating or air conditioning, and no battery conditioning occurred.

First case: February 17th, average ambient temperature at -6C (21F)
705.5 km / 114.3 kWh = 6.17 km/kWh (438.4 miles, 3.84 mi/kWh)

33638


Second case: February 21-22nd, average ambient temperature at 17C (63F)
706.5 km / 85.1 kWh = 8.30 km/kWh (439.0 miles, 5.16 mi/kWh)

33639


Some more miscellaneous details are noted in my blog.

On the cold day, I couldn't make the trip without charging mid-way. On the warm day, I had plenty of range left after arriving at the destination. The difference I experienced in the span of a few days was like night and day.
 

·
Registered
Joined
·
309 Posts
There's been a big temperature swing last week in my country, which is probably related to that extreme cold that hit Texas at a similar timeframe. I made a couple of very similar long-distance trips on both the day when it was the coldest, and when it got unusually warm.

About 80% of each of the entire trip was made on the expressways, with speed pegged at 100 km/h (62 mph) on the dashboard. I was not using any heating or air conditioning, and no battery conditioning occurred.

First case: February 17th, average ambient temperature at -6C (21F)
705.5 km / 114.3 kWh = 6.17 km/kWh (438.4 miles, 3.84 mi/kWh)

View attachment 33638

Second case: February 21-22nd, average ambient temperature at 17C (63F)
706.5 km / 85.1 kWh = 8.30 km/kWh (439.0 miles, 5.16 mi/kWh)

View attachment 33639

Some more miscellaneous details are noted in my blog.

On the cold day, I couldn't make the trip without charging mid-way. On the warm day, I had plenty of range left after arriving at the destination. The difference I experienced in the span of a few days was like night and day.
You are like Eskimo Man tough run without any heating at all in -6°C .... How about 2.3 miles per kWh or less in deep snow packed roads and average -31°C ....I definitely don't spare on cabin heat 74°F...
And from your infotainment screen you didn't ever have battery heater kicking at all....
 

·
Registered
Joined
·
489 Posts
That is weird... what could cause 25% drop?
Denser air? Higher rolling resistance (tire pressure dropped due to temperature change?)?
since you did not use heat at all (any heated seat or steering wheel?), I cannot really see what could cause it. Batter thermal management is not the cause here as it would be preconditioned before you left.

Thanks for the share.
 

·
Moderator
Joined
·
1,249 Posts
Pretty consistent with AAA study citing about a 20-25% drop when temps are around 32F (0C).

From what I understand, more resistance in the battery and circuitry, dense air, increased rolling resistance all contribute to reduced efficiency in colder temps.
 

·
Registered
Joined
·
364 Posts
20% reduction in range is expected in winter. It is the composite result of heating and reduction in battery capacity. But here the reduction is in terms of mile / kWh, which takes out capacity factor. Without heating there isn't reason for the difference. It is puzzling.

-TL

Sent from my SM-N960U using Tapatalk
 

·
Registered
Joined
·
751 Posts
Discussion Starter #6
20% reduction in range is expected in winter. It is the composite result of heating and reduction in battery capacity. But here the reduction is in terms of mile / kWh, which takes out capacity factor. Without heating there isn't reason for the difference. It is puzzling.

-TL

Sent from my SM-N960U using Tapatalk
As @ARob said, the car is definitely subject to more environmental resistance like denser air and higher rolling resistance in colder weather. I've been observing the power consumption under constant 100 km/h driving on a flat terrain with no cabin AC / heating and no battery conditioning. Generally speaking it's gets to be about 13 kW in the middle of summer, while it goes up to 14 kW in Spring / Autumn. Around freezing it's about 15 and I've seen it do 16-17 while making the first run shown in the initial post.
 

·
Registered
Joined
·
489 Posts
On your second trip you drove 439 miles on one charge? Outstanding!
He did... NOT :)

Look on the math. He used over 80 kWh and he did state he stopped for refills.
 

·
Registered
2020 Kinetic Blue Bolt Premier
Joined
·
17 Posts
What about wind, perhaps that was a major factor? I notice even at the same temperature a big difference between driving into the wind or with the wind. Weather like rain can also affect "mileage".
 

·
Registered
Joined
·
365 Posts
On your second trip you drove 439 miles on one charge? Outstanding!
From the blog it looks like the trip is 200 miles one way. Maybe there was 39 miles of additional driving in Seoul?

But 5.16 mi/kWh is outstanding. That would mean a range of 310 miles. I've never gotten anything near that. Maybe there was a tailwind each way?
 

·
Registered
Joined
·
364 Posts
Wind could be significant. Say you are doing 60mph. 5 mph headwind makes the apparent wind 65mph. 8% increase in speed, decreases efficiency by 17%.

-TL

Sent from my SM-N960U using Tapatalk
 
1 - 11 of 11 Posts
Top