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Basically, let it go down to about 35% and don't go over 80%.
 

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From my study of lithium battery health, here are my take-aways:
  • Especially avoid keeping a fully charged battery at elevated temperatures.
  • Minimize use of fast charging.
  • Stop charging 1 to 2 hours prior to let battery cool down before driving.
  • Charge during the night when temp is cooler.
  • Delay charging if battery is below 32 degF. Park in garage 1-2 hours to warm up.
  • Normally charge to 80% and drive to 25% before recharging.
  • Avoid frequent small % charges.
  • Reduce temperature of battery. Park in shade or garage, not in sun.
  • Minimize full throttle acceleration.
 

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From my study of lithium battery health, here are my take-aways:
  • Especially avoid keeping a fully charged battery at elevated temperatures.
  • Minimize use of fast charging.
  • Stop charging 1 to 2 hours prior to let battery cool down before driving.
  • Charge during the night when temp is cooler.
  • Delay charging if battery is below 32 degF. Park in garage 1-2 hours to warm up.
  • Normally charge to 80% and drive to 25% before recharging.
  • Avoid frequent small % charges.
  • Reduce temperature of battery. Park in shade or garage, not in sun.
  • Minimize full throttle acceleration.
A number of these things are already controlled and taken care of by the car itself, so there's very little reason to spend much time thinking about it. Perhaps if you owned a car without battery thermal management (like the Nissan LEAF), you'd need to be more concerned, but it's not really an issue for the Bolt EV.

Charging up to full and letting the battery sit a 100% is not ideal, but most EVs have a top buffer built in. So 100% isn't really 100%.

"Fast" charging really depends, and some automakers are okay pushing the limits of the cell chemistry at the cost of battery life. The Bolt EV actually fast charges slower than its cell-rating of 1 C (the Bolt EV's max charging rate is about .9 C).

The Bolt EV actively manages its temperature, so leaving immediately after charging has no real impact. This is one of the reasons I recommend DCFC to 65% to 70% rather than leaving immediately after the step down at 50%. When the Bolt EV steps down to ~100 A charging current, it starts aggressively managing battery temperature (drawing additional power from the charger). Your battery can be a whole 10 F or more cooler if you leave at 65% instead of 55%.

Again, charging at night doesn't really matter. The Bolt EV will use power to condition the battery when charging, day or not. Also, charging below freezing doesn't matter. If the battery is too cold to charge, the Bolt EV simply won't charge. It will warm the battery until the battery is warm enough to charge.

As for your final point about hard accelerations, it really depends again on the vehicle. The Bolt EV's battery pack is rated for over a 300 kW output, so being derated to 160 kW max power draw means that even hammering the accelerator won't cause a significant amount of wear to the battery.
 

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Good analysis from NewsCoulomb and it shows the excellent design engineering that went into the battery management system of the Bolt. It also demonstrates the high value of computers and software in wringing out longer life in a lot of machinery these days.
 

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From my study of lithium battery health, here are my take-aways:
  • Especially avoid keeping a fully charged battery at elevated temperatures.
  • Minimize use of fast charging.
  • Stop charging 1 to 2 hours prior to let battery cool down before driving.
  • Charge during the night when temp is cooler.
  • Delay charging if battery is below 32 degF. Park in garage 1-2 hours to warm up.
  • Normally charge to 80% and drive to 25% before recharging.
  • Avoid frequent small % charges.
  • Reduce temperature of battery. Park in shade or garage, not in sun.
  • Minimize full throttle acceleration.
If one really believed and practiced all of the above, it would be impossible to road-trip a BEV, especially in summer or winter.

Even though road-trips are not an issue for me, I believe the GM engineer who told me, "The Bolt is as idiot-proof as 21st-century technology can design and build. Just drive it as you usually do and plug it in whenever you think of it."

jack vines
 

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I'm glad I don't have to park DOS anymore.
For those who are of this century, hard drives have read/write heads which fly above the spinning disks while the drive is powered. When power is removed, the heads no longer fly, so they need to be told to safely park before being switched off. Up to the mid-'80s hard drives didn’t have this as an auto feature, so their heads would land on the disk surface, which could sometimes damage the surface, thus, the need for the manual "park" command.

jack vines
 

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  • Avoid frequent small % charges.
This is the first I'm hearing this recommendation. From my own study of Li batteries, I would recommend the opposite. Small percent charges are much less stressful on the battery than large percent charges. Looking at cycle life of a battery, it's common to see things like 1000 cycles from 0-100%, and 2500 cycles from 25-75%. Notice that the latter case is half the energy per charge but more than twice as many charge cycles.
 

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For those who are of this century, hard drives have read/write heads which fly above the spinning disks while the drive is powered. When power is removed, the heads no longer fly, so they need to be told to safely park before being switched off. Up to the mid-'80s hard drives didn’t have this as an auto feature, so their heads would land on the disk surface, which could sometimes damage the surface, thus, the need for the manual "park" command.

jack vines
Totally off topic now, I am an olde artist and animator. Zip drives where the thing for me to send out work, 30 secs at 30 fps of sequential images take a lot of space, and optical drives were expensive.
 

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If one really believed and practiced all of the above, it would be impossible to road-trip a BEV, especially in summer or winter.

Even though road-trips are not an issue for me, I believe the GM engineer who told me, "The Bolt is as idiot-proof as 21st-century technology can design and build. Just drive it as you usually do and plug it in whenever you think of it."

jack vines
Once again you are totally missing the point. The Bolt is capable, able and ready to anything it was designed to do. One can practice all of the mentioned tips and still, when needed, accelerate hard, charge to 100% when hot etc. etc.
Why do you need to make it an either or proposition? If I do the best practices 75% of the time and the "not so best but within design parameters" 25% of the time I am still doing better for the batteries over the long term.

If I have a new set of tires I can burn them out in 20,000 miles or make them last to 60,000. Or I can do a little of both and make them last to 40,000 miles.

You seem threatened by the fact that the entire LI-ion battery industry, and scientists agree that there are great, good, and and not so good ways to take care of battery packs. Your GM engineer is just regurgitating the company line as to make the Bolt less scary to the general public. Is he/she correct? Yes up to a certain point. Can one do better? I like to believe that if I take care of my batteries that when I do ask from them all they can give I know I have put in the effort to meet them halfway.

So yes, road trip your Bolt, winter, summer, whatever. Charge to 100% in 100 degree weather if you need to. Just understand that there are physical laws of battery chemistry you can not dispute just because they are inconvenient to you. I bet if you asked your engineer the right questions they would agree.
 

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This is the first I'm hearing this recommendation. From my own study of Li batteries, I would recommend the opposite. Small percent charges are much less stressful on the battery than large percent charges. Looking at cycle life of a battery, it's common to see things like 1000 cycles from 0-100%, and 2500 cycles from 25-75%. Notice that the latter case is half the energy per charge but more than twice as many charge cycles.
i think that the issue with lots of small charges is that the BMS can loose track of the "full" and "empty" points over time if you only do small charges.

As far as Eric's point of most cars having a top and bottom buffer to the battery, the paranoia in the Tesla community about not going over 90% unless you have too leads me to believe that they are ALL misinformed (possible), or that Tesla's have very little top buffer compared to other EV's. From what I have seen most Tesla drivers will not go over 90% even when doing an overnight L2 charge before a road trip. Watching that video, it seems that Tesla promulgates and encourages the paranoid behavior of the Tesla community.

Keith
 

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I believe the GM engineer who told me, "The Bolt is as idiot-proof as 21st-century technology can design and build. Just drive it as you usually do and plug it in whenever you think of it."
WHOLEHEARTEDLY CONCUR with this statement. Seems to me some people on this forum are WAY overthinking the whole battery management topic. But that's just me...
 

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i think that the issue with lots of small charges is that the BMS can loose track of the "full" and "empty" points over time if you only do small charges.

As far as Eric's point of most cars having a top and bottom buffer to the battery, the paranoia in the Tesla community about not going over 90% unless you have too leads me to believe that they are ALL misinformed (possible), or that Tesla's have very little top buffer compared to other EV's. From what I have seen most Tesla drivers will not go over 90% even when doing an overnight L2 charge before a road trip. Watching that video, it seems that Tesla promulgates and encourages the paranoid behavior of the Tesla community.

Keith
Tesla Engineers are very aggressive with the technology in many ways. Some of their early chargers caught fire because they pushed them too hard for example. (No I’m not pushing FUD, these are facts). It wouldn’t surprise me at all if Tesla was pushing their batteries to the limit to get the max EPA range for the buck. GM is much more conservative, in part because they are a bigger target to sue.
 

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i think that the issue with lots of small charges is that the BMS can loose track of the "full" and "empty" points over time if you only do small charges.

As far as Eric's point of most cars having a top and bottom buffer to the battery, the paranoia in the Tesla community about not going over 90% unless you have too leads me to believe that they are ALL misinformed (possible), or that Tesla's have very little top buffer compared to other EV's. From what I have seen most Tesla drivers will not go over 90% even when doing an overnight L2 charge before a road trip. Watching that video, it seems that Tesla promulgates and encourages the paranoid behavior of the Tesla community.

Keith
Tesla Engineers are very aggressive with the technology in many ways. Some of their early chargers caught fire because they pushed them too hard for example. (No I’m not pushing FUD, these are facts). It wouldn’t surprise me at all if Tesla was pushing their batteries to the limit to get the max EPA range for the buck. GM is much more conservative, in part because they are a bigger target to sue.
It's possible, but I believe Tesla's actually do have a bit of a top buffer. Bjorn Nyland was doing a video about it, and what he was addressing was the typical 6-8% battery degradation that the NCA cells see in the first year or so of ownership. He believes that top buffer is only there to mask that degradation.

That being said, even if 100% isn't 100%, charging to a slightly lower SOC will still preserve some battery life. If I had a Bolt EV with Target Charge Limit, I'd rarely charge past 80% because my daily driving cycle only requires about 40% to 50% of my battery. For someone who only uses 30% of their capacity regularly, charging to 70% makes sense. I still have no reservations about charging to 100% for trips, though.
 
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