That would depend on your utility rates, and when you charge. We live out in the country with a coop electric utility. We have a flat rate for electricity 24/7/365.
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L2 charging doesn't follow a curve like DCFC, it will maintain constant charging speed up to around 100%, maybe tailing off slightly at 98-99% for cell balancing. So, utility costs shouldn't be a consideration. The logic is, DCFC generates heat from higher current (amps) and needs to slow the pace. At 90% or more, the charging speed drops to near the speed of AC charging. So with AC charging, you never have to slow down until you get to the cell balancing phase.
On lower powered DCFC, the charging doesn't typically slow until higher state of charge. The following chart applies to the original 60kWh packs in older Bolts, but the concept is similar with newer packs, but follows a curve rather than step downs. Notice the higher SOC at lower kW charging speeds before the step downs occur.
![Rectangle Font Slope Parallel Pattern]()
When charged > 90%, regen will be limited for the first part of your journey.
Lots of articles advise not charging to 100%, that may or may not be as true for EVs as for laptops and other devices that lack thermal conditioning, but why risk it? If 80% is adequate for daily needs, use it. When planning a longer trip, charge to 100%, and if possible target finishing the charge as close to departure time as possible to avoid sitting at 100% for lengthy periods.
There may be headroom at the top, above 100%. But it is not accessible, and some who have dug in deep claim Bolt has very little room past 100%. It isn't like volume measurements, it is a voltage question. Pack voltages are kept within "safe" ranges so as to not stress cells.
The 80% suggestion for public charging is as much about slow DCFC past 80% as it is opening access for others. On trips, your strategy plays out better by making more stops and keeping SOC in the faster part of the charging curve. Charging from 80-100% on DCFC probably takes more time than 20-60% in most cases, so you will make better time avoiding >80% in most cases.
On lower powered DCFC, the charging doesn't typically slow until higher state of charge. The following chart applies to the original 60kWh packs in older Bolts, but the concept is similar with newer packs, but follows a curve rather than step downs. Notice the higher SOC at lower kW charging speeds before the step downs occur.
When charged > 90%, regen will be limited for the first part of your journey.
Lots of articles advise not charging to 100%, that may or may not be as true for EVs as for laptops and other devices that lack thermal conditioning, but why risk it? If 80% is adequate for daily needs, use it. When planning a longer trip, charge to 100%, and if possible target finishing the charge as close to departure time as possible to avoid sitting at 100% for lengthy periods.
There may be headroom at the top, above 100%. But it is not accessible, and some who have dug in deep claim Bolt has very little room past 100%. It isn't like volume measurements, it is a voltage question. Pack voltages are kept within "safe" ranges so as to not stress cells.
The 80% suggestion for public charging is as much about slow DCFC past 80% as it is opening access for others. On trips, your strategy plays out better by making more stops and keeping SOC in the faster part of the charging curve. Charging from 80-100% on DCFC probably takes more time than 20-60% in most cases, so you will make better time avoiding >80% in most cases.
My answer to the original question is: yes. 
Charge to the level you need for your driving. In general, Li batteries should not be 100% charged all the time, so if you can manage your regular driving on 80% without routinely dropping below 20%, by all means do that; the battery will deteriorate more slowly. Charging to 100% at home can usually be done overnight on a Level 2 charger as easily as to 80%, and the Level 2 charge rate (see the charge curves posted above) doesn't really drop off until the battery state of charge is over about 90%, but in general charging to 100% should be done only when it's really needed for a trip or other reasons.
I did charge to 100% recently, for the first time in months, to make sure I would have enough charge to sit in a heated car during an expected extended power outage due to weather; so of course, being prepared, the outage didn't happen. No problem, I don't do it often, and the excess will burn off quickly with a few shopping or post office runs in cold, rainy weather. After which I'll turn hilltop mode on again - what the oldest Bolts (mine's a 2017) have instead of desired charge level, limits charge to about 90%.
As another noted, the recommendation to stop at 80% with a DC charger (away from home) is because the charge rate drops off a cliff at that point, so it's not worth it to cram that last 20% into the battery at DC charging prices, and with That Guy with an Audi or F150 waiting for your plug. You won't go quite as far starting at 80% on a road trip, but you still should be able to go for 2 hours or so; I've planned for 2 hours driving, 1 hour charging (and whatever else is needed during the stop), and it usually works out about like that.
Another reason for not charging to 100% if you don't really need it is regenerative braking. That's why they call the mode "hilltop" in the old Bolts. If the battery's 100% full, there's no room for adding charge while braking or going downhill. Starting at 80-90% gives you space for that even if you live up a hill (as I do).
Just some things to think about.
Charge to the level you need for your driving. In general, Li batteries should not be 100% charged all the time, so if you can manage your regular driving on 80% without routinely dropping below 20%, by all means do that; the battery will deteriorate more slowly. Charging to 100% at home can usually be done overnight on a Level 2 charger as easily as to 80%, and the Level 2 charge rate (see the charge curves posted above) doesn't really drop off until the battery state of charge is over about 90%, but in general charging to 100% should be done only when it's really needed for a trip or other reasons.
I did charge to 100% recently, for the first time in months, to make sure I would have enough charge to sit in a heated car during an expected extended power outage due to weather; so of course, being prepared, the outage didn't happen. No problem, I don't do it often, and the excess will burn off quickly with a few shopping or post office runs in cold, rainy weather. After which I'll turn hilltop mode on again - what the oldest Bolts (mine's a 2017) have instead of desired charge level, limits charge to about 90%.
As another noted, the recommendation to stop at 80% with a DC charger (away from home) is because the charge rate drops off a cliff at that point, so it's not worth it to cram that last 20% into the battery at DC charging prices, and with That Guy with an Audi or F150 waiting for your plug. You won't go quite as far starting at 80% on a road trip, but you still should be able to go for 2 hours or so; I've planned for 2 hours driving, 1 hour charging (and whatever else is needed during the stop), and it usually works out about like that.
Another reason for not charging to 100% if you don't really need it is regenerative braking. That's why they call the mode "hilltop" in the old Bolts. If the battery's 100% full, there's no room for adding charge while braking or going downhill. Starting at 80-90% gives you space for that even if you live up a hill (as I do).
Just some things to think about.
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