Loss of miles / charge

[Anonymous]

I have owned my Bolt for about 2.5 months. We love our new car. I do have a concern about recent mileage loss when fully charged. Three weeks ago we left for a two week vacation. We would normally show 225 - 235 miles to go when fully charged. When we left for our vacation, our car had 200 miles left on the charge. We returned 16 days later. When activated upon our return, the mileage showed 199 miles left. Good so far. After driving it for a couple of days we needed to charge again. When the battery was fully charged, it showed 195 miles left at full charge. Since then we have charged it two more times. The first of these it showed 190 miles left on a full charge. The last time we charged, 192 miles remaining on a full charge.

I realize that the calculations for mileage are very dependent on the driving style of the owner but my driving style has not changed. Is there something to the problem of leaving the car sit for two weeks + that would suddenly show fewer remaining miles when fully charged?

 

[IMAdolt]

I have owned my Bolt for about 2.5 months. We love our new car. I do have a concern about recent mileage loss when fully charged. Three weeks ago we left for a two week vacation. We would normally show 225 - 235 miles to go when fully charged. When we left for our vacation, our car had 200 miles left on the charge. We returned 16 days later. When activated upon our return, the mileage showed 199 miles left. Good so far. After driving it for a couple of days we needed to charge again. When the battery was fully charged, it showed 195 miles left at full charge. Since then we have charged it two more times. The first of these it showed 190 miles left on a full charge. The last time we charged, 192 miles remaining on a full charge.

I realize that the calculations for mileage are very dependent on the driving style of the owner but my driving style has not changed. Is there something to the problem of leaving the car sit for two weeks + that would suddenly show fewer remaining miles when fully charged?

What's the weather like?

 

[iletric]

Ambient temp can do some real damage to your range. As soon as night temps hit 40s or less, you'll see a substantial loss of GOM range.

Also, do charge every night even if you drive 10 miles previous day. Battery does not take deep discharges well. Keep it full as much as possible to prevent premature range loss due to accelerated aging.

Full battery with no driving for a few days is not a problem. I think that's been debunked long time ago.

 

[ArthurL]

in the mid 20s F. here and my range is about 20 percent down.

 

[Anonymous]

Hey - thanks for the help. I will be sure to put it on the charger every night. Thanks again.

 

[elpwr]

Lithium batteries show minimum degradation when kept around 50% SOC. There’s plenty of evidence in technical papers and EV manufacturers such as Tesla to support this. Keeping the battery “as full as possible” is not good advice.

 

[michaellax]

I am going to repeat this post from another thread:

I enjoy the Grande size Starbucks coffee but it tends to splash out when driving through the cover's drinking hole.

I used to have them not fill it to the top to avoid this problem, but then over the long run, I was wasting money getting less coffee than I was paying for.

Finally, I ordered a Grande coffee in a Venti sized cup and the problem was solved. Then they developed a plastic green stick to plug closed the drinking hole in the coffee cup's cover and now I am back to my Grande cup again.

I waited for the Bolt EV because I wanted a 238 mile capacity car not an 80-100 mile capacity car or a 150 mile capacity car.

I find that most, if not all of those members of this forum who criticize full charging of the Bolt EV drive a different EV; ask them!

Nobody knows what engineering GM has provided to protect the battery but anecdotal evidence from drivers of the Spark EV and Volt suggest that those cars have suffered from low battery capacity loss over the last few years; ask them!

While the LEAF is the main capacity loss culprit for the last few years.

I am sticking with full charging my 238 mile Bolt EV.

 

[iletric]

in the mid 20s F. here and my range is about 20 percent down.

That's to be expected. Once winter's over and we hit 50s at night, your range will be back to original.

Winter driving is hard on range because on top of the loss you have to use a lot of heat. This is why it is do nice to have a 230 mile EV. Even with the loss of range it still has enough miles to call it a real car.

 

[elpwr]

I have a Tesla and a Bolt.

Charge my Tesla to 100% repeadly for a few days and you get the on screen message: “frequent full charging will result in premature battery degradation. Fully charge only when necessary for trips”

JB Straubel, Teslas chief engineer has stated the 50-62% storage range minimizes degradation.

There’s plenty of other evidence, published by experts, to confirm that the upper and lower extremes of SOC hasten li-ion battery degradation.

I won’t engage in an argument over this. But the “deniers” just don’t have the weight of evidence on their side.

 

[iletric]

We drove Spark 42,000 miles over 3 years with almost no loss of original range, doing full charge every night. I figure Bolt batteries, being of the same provenance as Spark's (LG chemistry), will over time perform in a same manner.

But we'll see. So far at 23,000 miles the Bolt battery has not blinked. I expect max of 10 miles drop at 50,000. Hopefully less.

Tesla has Panasonic chemistry. Different animal.

 

[TimBolt]

The Energy Information screen will show you what percentage of energy used is for propulsion / climate / battery conditioning. During the very mild fall here in the northeast the climate percentage was very small, somewhere between 0-5%. It’s been chillier the last few days, last climate percentage reading was 17%., and that energy use will lower the overall driving range estimate.

 

[boltage]

If your car has heated seats, using them consumes much less energy than using the cabin heat.

 

[michaellax]

We drove Spark 42,000 miles over 3 years with almost no loss of original range, doing full charge every night. I figure Bolt batteries, being of the same provenance as Spark's (LG chemistry), will over time perform in a same manner.

But we'll see. So far at 23,000 miles the Bolt battery has not blinked. I expect max of 10 miles drop at 50,000. Hopefully less.

Tesla has Panasonic chemistry. Different animal.

I have been waiting to read anecdotal evidence from Spark EV and Volt drivers here: Thank you!

Your history of 23K miles on the Bolt EV speaks volumes too!

I am "only" at 14K. What kind of driving gets you up to 23K?

 

[iletric]

I am "only" at 14K. What kind of driving gets you up to 23K?

With no range loss?

Well, we have 2 drivers. I am nice to the car and drive around 63 mph, and few hard accelerations. My kid who is the principal driver brings the car home with 3.7 average, so I know he speeds and accelerates like mad. The car remembers the previous average and shows it as decreased range, even though it resets at 3.9 upon recharge and new drive duty.

When I drive my 80 mile trips, I nurse it back to 4.1 and my range for the next day is 230-240 on fill-up at 50F nights. Ultimately, I see no range loss at this time. I think 40k is the mileage boundary when the battery will start showing a bit of loss, say about 5 miles for Bolt, no matter how it's driven.

I stand by my conjecture based on 7 years of experience with 4 different EVs that deep discharge is the biggest enemy of range retention and primary cause of range decline. This is what killed our Leaf1 besides heat, and our Soul EV that's getting a (free) brand-new battery at 47k miles, both result of DAILY deep discharges.

 

[SmokingRubber]

I just charged up ... it says I have 171 miles of range Every week it's dropping by 10 miles. @ 2.8 mi/kwh I usually drive 75mph with cruise control.

I'm taking it on a 200+ mile trip tonight to the bay area. I'll have to fast charge in Salinas. That's 160 miles away, I hope I make it to the charger. Maybe I'll stop for 15 minutes and get a quick shot of juice in King City or somewhere.

 

[boltage]

I stand by my conjecture based on 7 years of experience with 4 different EVs that deep discharge is the biggest enemy of range retention and primary cause of range decline. This is what killed our Leaf1 besides heat, and our Soul EV that's getting a (free) brand-new battery at 47k miles, both result of DAILY deep discharges.

A short range EV may require "harder" charge-discharge patterns than a long-range EV with similar battery chemistry and management (cooling, hidden buffer, etc.).

1. More likely to discharge deeply in daily use.
2. More likely to need to charge every day (i.e. more charging cycles).
3. More likely to need to charge to 100% instead of "hill top" or other slightly less than 100% level.
4. More likely to need to use a fast charger (if equipped to do so) during the day.

On the other hand, Teslas do seem to have reports of battery capacity loss. But if owners were frequently using the free Supercharging (on earlier models, at least) to top off during the day, that is along the lines of #4 (and maybe #3) above in being "harder" on the battery.

 

[desiv]

I stand by my conjecture based on 7 years of experience with 4 different EVs that deep discharge is the biggest enemy of range retention and primary cause of range decline.

Not so sure..
With my 2012 Leaf, I did a deep discharge frequently.
I have a 120 mile round trip commute.
Initially when I got it (used 3 years ago; it was low mileage in good shape) I could make it to work on a full charge, but would get low battery and sometimes very low battery.
This last year, I was down to 10 bars, and I was charging full at home over night. Driving 30 miles (highway speeds, and 1 lane, so I usually had cars behind me and I was doing 65) to a QC. Usually down to 45%ish, charge to 70%ish. Off towards work. Would be down around 25%.. Especially in winter, lower 20% was not uncommon.
But when I checked my battery against the chart by Tony Williams on mynissanleaf, my battery was exactly where it should have been for a 2012 based on age.
As I live in the Pacific Northwest, it was pretty cool, which I think was the key. Personally, I think heat is the one major killer.
Not full charges (which I did a lot, but never let sit that way), not low charges. In fact, I often wonder if the exercising of my battery as I did possibly helped... Not QCs, as the last year, I was doing 3 per day.
I think heat is the key, at least with the Leaf and it's lack of an active thermal management system.
Now, QCs raise heat, so if you are in a hot climate, QCs can make it worse...
So I don't think in general they are safe all the time. But I did LOTS and my battery was exactly where it was predicted to be based on age.

But that's just me.. ;-)

desiv

 

[desiv]

I stand by my conjecture based on 7 years of experience with 4 different EVs that deep discharge is the biggest enemy of range retention and primary cause of range decline.

Not so sure..
With my 2012 Leaf, I did a deep discharge frequently.
I have a 120 mile round trip commute.
Initially when I got it (used 3 years ago; it was low mileage in good shape) I could make it to work on a full charge, but would get low battery and sometimes very low battery.
This last year, I was down to 10 bars, and I was charging full at home over night. Driving 30 miles (highway speeds, and 1 lane, so I usually had cars behind me and I was doing 65) to a QC. Usually down to 45%ish, charge to 70%ish. Off towards work. Would be down around 25%.. Especially in winter, lower 20% was not uncommon and teens happened from time to time.
But when I checked my battery against the chart by Tony Williams on mynissanleaf, my battery was exactly where it should have been for a 2012 based on age.
As I live in the Pacific Northwest, it was pretty cool, which I think was the key. Personally, I think heat is the one major killer.
Not full charges (which I did a lot, but never let sit that way), not low charges. In fact, I often wonder if the exercising of my battery as I did possibly helped... Not QCs, as the last year, I was doing 3 per day.
I think heat is the key, at least with the Leaf and it's lack of an active thermal management system.
Now, QCs raise heat, so if you are in a hot climate, QCs can make it worse...
So I don't think in general they are safe all the time. But I did LOTS and my battery was exactly where it was predicted to be based on age.

But that's just me.. ;-)

desiv

 

[oilerlord]

On the other hand, Teslas do seem to have reports of battery capacity loss. But if owners were frequently using the free Supercharging (on earlier models, at least) to top off during the day, that is along the lines of #4 (and maybe #3) above in being "harder" on the battery.

I don't believe there is an EV on the market that is immune to battery capacity loss. Time will tell to what extent it will happen with the Bolt.

I think what you're getting at is that range / battery capacity loss is more about the operator's charging habits than it is about the car. Sure, some cars have better battery / thermal management than others but that can be mitigated by an owner that takes some basic steps to help maintain the battery's health for the long term.

 

[gpsman]

There are all types, sizes and shapes of batteries out there.

It seems to hold true that deep discharge cycles are bad for all of them. Even “deep cycle” lead-acid batteries that are better suited for this, still are healthier if you don’t do deep discharges.

While we are familiar with NiCd benefiting from an occasional deep discharge to erase “memory effect”, it is only common sense that avoiding the extreme ends of the state of charge range is healthy for the battery.

Now, Chevy probably already built-in this fact into the BMS of the car. This is almost certainly a 64 kWh pack, that is software limiting useage of the 60 kWh in the middle, leaveing some kind of safety buffer on either end of the SOC range.