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I read that other makes and models of EVs say you should not charge past 80% to allow for extra room in the battery for regenerative braking, among other reasons.

Will regularly charging the Bolt's battery to full cause battery degradation or any other harmful effect?
 

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Gm says charge away. But the warranty says 40% degradation in 8 years is okay. Hoping I have that info correct. Being lazy because I'm in a hurry. 40%/8 = 5% per year. No one has reported that much if any with one year old Bolts.
 

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The short answer is yes. Charging to full, running to empty, charging fast, regening hard, accelerating hard, all degrade the battery. And the 40% reduction is listed in the warranty for a reason. Will this happen to you? I am sure if you do all of these things, all day, every day, it is almost guaranteed. Moderation in all things, and Happy New Year!
 

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If you want to play it safe and you don't need a full charge every time you plug in... set it on "hilltop reserve" and forget it!
 

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The best way to preserve the battery is to drain it to about 30%, disconnect the 12v battery, and never drive or charge the car again. This is the recommended way to store the car for long periods in the user manual.

If you actually want to use the car as intended, it is fine to charge to full as needed. It won't hurt to use hilltop reserve mode, but there is no evidence it will significantly reduce any degradation.

The warranty is not necessarily a good indication of how much the battery will degrade. Tesla's battery warranty specifically excludes degradation. You could lose 50% in the first year and not be covered by the terms of their warranty (although they would almost certainly make a "good will" repair).

The LEAF is fairly unique in it's degradation propensity, and it is passively cooled - no liquid cooling, not even any fans to move air over the battery. The Bolt has 3 liquid cooling loops, one of which is dedicated to the battery.

Our Fit EV is plugged in virtually every night and charged to 100%. In 4 years and 40K+ we have not noticed any range loss. The Bolt has been shipping for a year, and I have not seen a single report of any capacity loss to date. All indications are that battery degradation will not be a big issue, so following the recommendations of GM's engineers is probably safe.

Plug it in as needed - every night is fine. If using hilltop reserve makes you feel better, no harm done as long as you periodically charge to 100% to balance the cells.
 

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Where about do you enable this option?
It's somewhere in the Energy settings menu (I think that's what it's called). You can set it to enable hill top reserve only at your home, or everywhere. I leave HTR enabled for home charging only, because otherwise there's gonna be that one time I need to charge 100% when road tripping where I forget to turn off HTR.
 

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Here's a link to a downloadable copy (pdf) of the owner's manual :

https://my.chevrolet.com/content/dam/gmownercenter/gmna/dynamic/manuals/2017/Chevrolet/BOLT EV/Owner's Manual.pdf

searching the manual finds the following on page 132 :

Energy Settings
{...}
Hill Top Reserve :
Select Off, On,On-HomeOnly,orOn- Away Only. See “Hill Top Reserve” in Regenerative Braking p. 213.


and on page 213 :


Hill Top Reserve

Hill Top Reserve enables regenerative braking efficiency to be maximized when driving from a higher elevation immediately after charging. When turned on, this feature will stop the charge before the battery is full, allowing space for energy from regenerative braking.

This feature also integrates with the Location Based Charging feature, allowing the system to be configured so it is enabled when at home (On - Home Only) or away (On - Away Only). See “Location Based Charging” under Programmable Charging p. 124.
 
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