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A little history - my Bolt is scheduled to be delivered in the next few days. I am replacing a 2013 Leaf that I have driven 100,000 miles (yes - 100 thousand). Original battery with over 90% capacity remaining. Based on my needs, I charged twice per day (home and work) every day for over 3 years. Vehicle range is about 75 real world miles if driven normally and running battery full cycle (100% to 5%). My needs were for a 55 mile cycle, so I could run from 100% to 25% or I could run from 80% to less than 10%. Nissan recommended that I not charge to 100% all of the time, so I ran in extreme range anxiety mode for three years. Drained battery and ran out of electrons twice.
That's the history.
What does Chevy recommend ?
Based on my daily needs:
I could run from 100% to 50% and charge once per day *or*
I could run from maybe 80% to 30% or something like that) *or*
I could run from 100% to near zero and charge every other day.
Is there any battery treatment guidance ?
 

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In general, you want to avoid charging a lithium pack to 100% actual SOC when possible. It is likely the Bolt won't actually be at 100% when indicated, just like your Leaf, but GM is probably using more of the "top" of the capacity than would be best for long life - just like Nissan. If you'll be driving the car right after charging to 100%, then it probably doesn't matter how you charge it. If the car will sit around for hours after charging, then you might want to use the "Hilltop Mode" that GM has snuck in, to let you charge to 90%.
 

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It's likely better to charge every day with a more shallow recharge than to charge every other day with a deep recharge. Using Hilltop Reserve (or whatever it's called) to stop charging 10% from the top probably helps battery life, especially if the car would sit like that for long periods of time (and even more so if left unplugged when nearly "100%" full).

On the other hand, GM probably hasn't set the top charge point at a level that will cause serious battery degradation and if left plugged in it will use the A/C system to keep the battery at a reasonable temperature. In fact, even unplugged, the Bolt EV battery will actively keep itself from getting too hot when at a very high level of charge, according to GM. GM has a good battery reputation with the Volt and Spark EV. We are unlikely to see the kinds of problems experienced by early LEAF owners.
 

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It's strange GM does not offer the ability to set the desired level of charge besides the hilltop reserve. Since most people might not use this feature it almost seems like they are inviting people to charge to 100% every night. I wonder if the 60KWh battery is really like the tesla 60 and top limited so it is safe to charge to 100% all the time...
 

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It's strange GM does not offer the ability to set the desired level of charge besides the hilltop reserve. Since most people might not use this feature it almost seems like they are inviting people to charge to 100% every night. I wonder if the 60KWh battery is really like the tesla 60 and top limited so it is safe to charge to 100% all the time...
It's because of what happened with the Leaf when Nissan introduced the handy 80% charge limit setting in 2013. (pre-2013 Leafs can also charge to 80% using the charge timer.) The EPA promptly used that against the car's range rating by averaging it with the 100% setting
 

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It's because of what happened with the Leaf when Nissan introduced the handy 80% charge limit setting in 2013. (pre-2013 Leafs can also charge to 80% using the charge timer.) The EPA promptly used that against the car's range rating by averaging it with the 100% setting
Tesla gets around that by having a slider that can be set to any charge level instead of a single fixed 80% level. I see no reason why GM or Nissan couldn't do that too.
 

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That's true, but Nissan hasn't brought it back and it looks like GM just did the sidestep around it with hilltop mode. I suspect that it has to do with them not wanting to admit that charging for the full range can be an issue.
 

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That's true, but Nissan hasn't brought it back and it looks like GM just did the sidestep around it with hilltop mode. I suspect that it has to do with them not wanting to admit that charging for the full range can be an issue.
My opinion (very different from LeftieBiker and others) is that hilltop mode is exactly what it implies. It allows you to start the day with a "full charge" but room to utilize the regen energy that otherwise would not be available (to to either terrain or temperature).
Only time will reveal the real world durability and resistance to degradation of the Bolt batteries. With a new chemistry and unknown actual vs usable pack size, drawing conclusions from older studies will have reduced relevance. LG/GM have not released enough data to draw definitive conclusions.
As a general rule, those that owned early (and even mid) gen LEAFs are adamant that the owner must take special precautions to preserve battery capacity. Owners/lessees of other brands very much less so.

I'm NOT saying that charging to a lower %SOC will have no effect - I just don't believe it will be magnitudes different than following GM's recommendation to charge the car every night (unless it will be idle for weeks). Charging to the 90% "hilltop" mode certainly won't hurt, but may or may not be necessary - particularly on a leased vehicle.

Leftie:
Do you have a link to a study with long term effects of charging nightly to 100% vs 80%? Preferably from a SOC >50% (and not at or near 0%).
 

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Nissan says that it makes no discernible difference, but then they have a vested interest in saying that. I know of no other studies and Nissan never releases details. It's widely accepted that lithium packs in general do better at less than 100%, so rather than assume that LG and GM have reinvented an improved version of the wheel, I'm going to assume that it's still a "wheel."
 

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Nissan says that it makes no discernible difference, but then they have a vested interest in saying that. I know of no other studies and Nissan never releases details. It's widely accepted that lithium packs in general do better at less than 100%, so rather than assume that LG and GM have reinvented an improved version of the wheel, I'm going to assume that it's still a "wheel."
We've been charging our Fit EV to 100% virtually every night for 3 years with no discernable loss of range. No Fit EV owner has reported more than "maybe a mile or two" of range loss.
Battery chemistry does play a roll, and no car maker really allows you to charge to 100% anyway.

Yet "everyone" says that there are multiple studies that prove charging to 100% is very bad for all Li-Ion batteries....
 

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My opinion (very different from LeftieBiker and others) is that hilltop mode is exactly what it implies. It allows you to start the day with a "full charge" but room to utilize the regen energy that otherwise would not be available (to to either terrain or temperature).
Only time will reveal the real world durability and resistance to degradation of the Bolt batteries. With a new chemistry and unknown actual vs usable pack size, drawing conclusions from older studies will have reduced relevance. LG/GM have not released enough data to draw definitive conclusions.
As a general rule, those that owned early (and even mid) gen LEAFs are adamant that the owner must take special precautions to preserve battery capacity. Owners/lessees of other brands very much less so.

I'm NOT saying that charging to a lower %SOC will have no effect - I just don't believe it will be magnitudes different than following GM's recommendation to charge the car every night (unless it will be idle for weeks). Charging to the 90% "hilltop" mode certainly won't hurt, but may or may not be necessary - particularly on a leased vehicle.

Leftie:
Do you have a link to a study with long term effects of charging nightly to 100% vs 80%? Preferably from a SOC >50% (and not at or near 0%).
The chemistry of the Bolt batteries is not new (just an evolution) - here is some more detailed information from Bolt engineers (battery details start around 16:30):

 

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We've been charging our Fit EV to 100% virtually every night for 3 years with no discernable loss of range.
But even putting battery technology aside that may not be relevant to the Bolt's situation if the Fit EV has a larger hidden buffer beyond the indicated "100%" mark than the Bolt does.
 

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Activating hill top reserve to limit charging to 90% is probably the easiest way to "take care" of the battery....if that is even needed. The Bolt also has a 40% setting (???) but sounds like that wouldn't cut it for OP.

Fact is we just don't know how well the battery will hold up over time. However, looking at the Volt and (small number) of Spark EVs, I don't think we have too much to worry about. However, at least using the hilltop reserve trick is probably a good idea for someone that is owning the Bolt for the long haul.
 

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But even putting battery technology aside that may not be relevant to the Bolt's situation if the Fit EV has a larger hidden buffer beyond the indicated "100%" mark than the Bolt does.
Part of my point - we don't know tha actual pack size of the Bolt.

The Fit EV has consistently shown about ~18.5 - 18.8 kWh "useable" (as measured using miles/kWh and % SOC remaining) off a report 20 kWh pack, but no useable vs actual pack size is available there either.

If the Bolt uses an actual pack size of 70.2 kWh (288 cells x 3.75 V x 65 Ah), it may have a very large buffer.
 

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I think most have nailed it - what we see on the dash as 0% and 100% are not actually 0 and 100, but more likely 10 or 20% on the low end and 80-90% on the top end. You cannot drain a LION battery to 0% as it would kill the battery. Also, charging to a full 100% would damage the battery.

So that means the battery might be slightly bigger than 60kwh, or the usage is being calculated differently. I'm betting the battery is a little larger than 60.
 

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I think most have nailed it - what we see on the dash as 0% and 100% are not actually 0 and 100, but more likely 10 or 20% on the low end and 80-90% on the top end. You cannot drain a LION battery to 0% as it would kill the battery. Also, charging to a full 100% would damage the battery.

So that means the battery might be slightly bigger than 60kwh, or the usage is being calculated differently. I'm betting the battery is a little larger than 60.
GM has been quoted saying the Bolt uses "almost all" of its capacity. So while it may be bigger than 60 kWh, it's probably not much bigger. I believe the usage rate is at least 95%, just like the Spark EV.
 

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It may be a little like formatted storage capacity on a disk or SSD drive, you lose a little and that's how it's designed. As one of many who will lease, it's one area that I'm happy to let the design team take care of for me. (Suspension, tires, audio...not so much! : ) They know that most will just plug it in after work, and that will make precious little difference because of the way the engineers have set the battery kWh and usage rate. Range anxiety affects adoption of EVs a lot more than concerns for end of life residual battery capacity, so it makes sense that GM is using almost all of its capacity to obtain the range the Bolt is known for.
 

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GM has been quoted saying the Bolt uses "almost all" of its capacity. So while it may be bigger than 60 kWh, it's probably not much bigger. I believe the usage rate is at least 95%, just like the Spark EV.
Hmmm. Never seen or heard that before.
Do you have a link?
 

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As I understand it, the purpose of hilltop mode is to avoid the situation where the battery won't take any more regen, leaving the disk brakes doing the whole job where they usually only contribute part of the braking.
This leads to an unexpected and unpredictable considerable reduction in braking power and a hard brake pedal when you try to stop at the bottom of a hill first thing in the morning. It can be a real adrenaline rush in my Spark EV when it catches you unaware.
I'd guess the Chevy engineers left plenty of headroom when they chose what voltage to show as "Full Charge".
 

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It may be a little like formatted storage capacity on a disk or SSD drive, you lose a little and that's how it's designed. As one of many who will lease, it's one area that I'm happy to let the design team take care of for me. (Suspension, tires, audio...not so much! : ) They know that most will just plug it in after work, and that will make precious little difference because of the way the engineers have set the battery kWh and usage rate. Range anxiety affects adoption of EVs a lot more than concerns for end of life residual battery capacity, so it makes sense that GM is using almost all of its capacity to obtain the range the Bolt is known for.
Add to that the fact that charging stations are only going to increase in numbers with the whole EV world gaining much more momentum. Plus we should be able to use the Tesla charging network, doubt they'll say no to our money.

Plus we should see malls, parkades, starbucks locations, mcdonalds locations, etc. offer charging spots for obvious reasons.
 
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