Chevy Bolt EV Forum banner
181 - 200 of 271 Posts

·
Registered
Joined
·
229 Posts
Pretty disappointed today. Drove 130 miles today using 29.7 kWh, dropping the battery from 100% to 43%.

29.7/0.57 = 52.1 kWh battery capacity. My bolt has 12K miles.

Can knowledgeable folks weigh in on whether this is a meaningful test if I’m not drawing the battery down closer to zero?

I may try such a test later on, but based on this, I have very little confidence in what my target discharge should be. I don’t want to get stranded miles from home after spending only 52 kWh.
 

·
Registered
Joined
·
2,070 Posts
Pretty disappointed today. Drove 130 miles today using 29.7 kWh, dropping the battery from 100% to 43%.

29.7/0.57 = 52.1 kWh battery capacity. My bolt has 12K miles.

Can knowledgeable folks weigh in on whether this is a meaningful test if I’m not drawing the battery down closer to zero?

I may try such a test later on, but based on this, I have very little confidence in what my target discharge should be. I don’t want to get stranded miles from home after spending only 52 kWh.
If conditions were cold, that might explain it a little.

For a good test, if you haven't run it down fairly low lately, I'd say you need to run it down to 20% or less to help the Bolt calibrate, then, charge it up, and then run it down again.
 

·
Registered
2017 LT upgraded to 2020 Premier
Joined
·
83 Posts
Pretty disappointed today. Drove 130 miles today using 29.7 kWh, dropping the battery from 100% to 43%.

29.7/0.57 = 52.1 kWh battery capacity. My bolt has 12K miles.

Can knowledgeable folks weigh in on whether this is a meaningful test if I’m not drawing the battery down closer to zero?

I may try such a test later on, but based on this, I have very little confidence in what my target discharge should be. I don’t want to get stranded miles from home after spending only 52 kWh.
Today I did similar calculation: used 31 kwh and the app showed 47% remaining battery. 31/0.53 = 58.5 kwh. Drove on mostly flat road. The car has 31.5k miles on the odometer. So it looks like it lost 1% battery per 20k miles, assuming initial capability is indeed 60kwh and the above numbers are accurate.
 

·
Registered
Joined
·
229 Posts
I had a chance this past Tuesday to do a pretty deep discharge. 208 miles using 45.8 kWh, dropping from 100% down to 21% (but rebounded to 22% after the trip). Using the 79% correlates to a usable 58.0 kWh.

I can live with that. Temp was about 40F on first half and 65F on the return trip.
 

·
Registered
Joined
·
783 Posts
I had a chance this past Tuesday to do a pretty deep discharge. 208 miles using 45.8 kWh, dropping from 100% down to 21% (but rebounded to 22% after the trip). Using the 79% correlates to a usable 58.0 kWh.

I can live with that. Temp was about 40F on first half and 65F on the return trip.
The range varies with driving conditions, and environmental factors. Its my understanding that it is so variable that its impossible to do a simple calculation to figure the battery capacity, which is also going to vary to some degree with environmental factors. For example, my range from winter to summer bounces about very dramatically between 150 miles and 250 miles on a day to day basis, so with such variability in the data its impossible to come up with a meaningful battery capacity number on any one day. So, the variability in the data you are collecting is so big on a day to day basis that its impossible to tease out the battery capacity with good precision to distinguish between say 55 kWh and 58kWh or 60 kWh. The rebound mentioned above is a small example of some but not all of the variability.
 

·
Registered
Joined
·
381 Posts
I had a chance this past Tuesday to do a pretty deep discharge. 208 miles using 45.8 kWh, dropping from 100% down to 21% (but rebounded to 22% after the trip). Using the 79% correlates to a usable 58.0 kWh.

I can live with that. Temp was about 40F on first half and 65F on the return trip.
What your total mileage? 58kWh usable after how many miles?
 

·
Registered
Joined
·
229 Posts
I’m just over 13K, but this is the first time I’ve been able to test like this with anywhere close to a full discharge, so I have no prior reference point, really.
 

·
Registered
Joined
·
229 Posts
I don’t have a similar value at ~0 miles to compare it to, so I’m hesitant to call it 3% degradation. Based on all the anecdotal evidence I’ve read here, I think it might be more likely I started with less than 60, vs accelerated degradation.
 

·
Registered
Joined
·
1,241 Posts
Is the absolute most accurate way to measure the capacity going from a full charge and then driving it down to 0% battery on a series of trips and then dealing with roadside assistance? I would assume you would then look at energy use screen since last full charge as You are stranded. In one of my longer trips I went around 220 miles and it showed "low" remaining when I got home. My energy use screen showed I used 58.3 Kwh so I know I have at least 58.3 Kwh capacity per full 100% charge. I assume since I was still able to drive it and possibly drive a few more miles my actual capacity would be real close to the specified 60.0 Kwh pack rating.
 

·
Registered
2021 Bolt Premier
Joined
·
3,508 Posts
Is the absolute most accurate way to measure the capacity going from a full charge and then driving it down to 0% battery on a series of trips and then dealing with roadside assistance? I would assume you would then look at energy use screen since last full charge as You are stranded. In one of my longer trips I went around 220 miles and it showed "low" remaining when I got home. My energy use screen showed I used 58.3 Kwh so I know I have at least 58.3 Kwh capacity per full 100% charge. I assume since I was still able to drive it and possibly drive a few more miles my actual capacity would be real close to the specified 60.0 Kwh pack rating.

The trick is to finish the trip in your own neighborhood, and limp home on reduced power. No roadside assistance necessary.
 

·
Registered
Joined
·
44 Posts
yep. I did that (blast the heater to get the last kwh or 2 out) last month and got 58.3 kwh from full to empty.
I am under the impression that the full to empty number is variable . As I've taken out 56.x before and still had a 3 kwh bar

at the bottom.
 

·
Registered
Joined
·
267 Posts
If anyone wants to contribute, I just created a public G Sheet where we can post our data, I have entered my 2 data points.

https://docs.google.com/spreadsheets/d/1ZIgmv9f_QHJ3DDzKWDz_b4k8Yg7HvMn3oeAFbuuqAEw/edit?usp=sharing
Thanks,

This sheet was somewhat helpful, but does anyone know where else I can find additional information or anecdotes or reports of degree of degradation of Bolts in hot climates? The youtube video of the original poster is very detailed and into the topic of measuring his degradation, but I only made it partway through as it couldn't tell if it was going to speak to the exact questions I have.

Background - I experienced some of the classic Arizona increased degradation on a 2012 Leaf and now am possibly experiencing it on a 2013 Volt. Ok, the Volt is an early effort from GM and LG Chem, I can surely appreciate its many good qualities, and to be sure after 55k miles its good to still have roughly 30 EV miles at hand, but still, it makes me wonder how things are looking with the Bolt in Arizona and other hot climate areas, once drivers get upwards of 50k or 100k miles.
 

·
Registered
Joined
·
5,449 Posts
and other hot climate areas, once drivers get upwards of 50k or 100k miles.
I'm in to my second summer with my 2017. But, I've only got 15K+ miles. I'll have to get back to you in a couple years.

To limit exposing the battery to the 100F+ days, I've diverted some AC to my insulated garage. Keeps the temps below 90F where the manual says to keep it plugged in. I've not done any battery testing. I've seen the battery condition on multiple occasions when I've been out and about in the hot weather. If I can, I'll find a tree to park under. But sometimes it just has to sit in the heat. I've never caught the car conditioning the battery when off unplugged. But have seen it immediately start conditioning the battery when turned on.
 

·
Registered
Joined
·
267 Posts
I'm in to my second summer with my 2017. But, I've only got 15K+ miles. I'll have to get back to you in a couple years.

To limit exposing the battery to the 100F+ days, I've diverted some AC to my insulated garage. Keeps the temps below 90F where the manual says to keep it plugged in. I've not done any battery testing. I've seen the battery condition on multiple occasions when I've been out and about in the hot weather. If I can, I'll find a tree to park under. But sometimes it just has to sit in the heat. I've never caught the car conditioning the battery when off unplugged. But have seen it immediately start conditioning the battery when turned on.
Thanks, some of these points have been on my mind.

On conditioning the battery toward cooler when the vehicle is not plugged in, we can understand why the vehicle engineers may have chosen not to do this, but it makes me wonder if there is any room there at all for compromise. Maybe allow the car to do this to a limited extent down to say 30%, perhaps along with some dashboard communication to the person parking the car before they turn it off that the temperature is such that it would be a good idea to park plugged in?

I like your garage solution. I have a call in to a local HVAC outfit, with one of the goals to see about installing some limited cooling in my garage.
 
181 - 200 of 271 Posts
Top