[Wavelet81]

Hello everyone, I recently purchased a Chevy bolt 2019 last October. I’ve been reading up on different types of batteries and I’m interested in the best practices for maintaining my existing battery on my vehicle as I live in New England and we experience colder weather. I have the option to charge at work with level 2 charger ( However option is dependent on availability as other electric vehicles use chargers) but am thinking about best practices as leaving the vehicle at low charge level overnight during cold weather might damage battery. I started out with level 1 charger at home but now have a level 2 charger installed as of February. My understanding is that regardless of battery type best practice is to have the battery charged to a minimum of 50 % to maintain battery longevity. During colder weather to have the battery charging and conditioning over night. I have at times drawn the battery down on the Chevy bolt to about 60-40 miles of distance to opt to be able to charge at work for the electrical cost savings. In your experience, Should I be concerned about damaging the battery on my vehicle during colder weather conditions during these winter conditions. Generally, I plug the car into my level 2 charger and preheat the vehicle before I head into work. Generally, I don’t preheat the vehicle before I leave work. I load up and go. Any advice would be appreciated.

 

[p7wang]

This gives you good general info on Li-ion battery. There's charts on state of charge (SOC), temp, depth of discharge (DOD). Keeping the SOC between 75% and 25% seems the recommendation for longest life (energy dispensed). If you have charging at home and work, maybe set the target charge to 67% (4 bars above the mid point) or 72% (the 3/4 full mark). This is because we know the in car display of 100% is not really 100% and the in car display of 0% is not really 0%.

How to Prolong Lithium-based Batteries - Battery University

Discover what causes Li-ion to age and what the battery user can do to prolong its life

batteryuniversity.com

 

[Wavelet81]

Good information but standard. Have you seen any similar studies with relation to depth of discharge in relation to age or cycles of battery or frequency? For instance is it more damaging discharge the battery deeper later in life or earlier? At this point, as the battery is brand new or less than a year old can I feel more comfortable discharging it to about a 50 mile distance infrequently or should I be more concerned that I’m damaging the battery earlier in its life?

 

[RichardC]

Figure 6 of that same article concludes the three highest life prolonging charge strategies are from best 65% to 75%, followed by 45% to 75% and then 25% to 75%. You need to choose for yourself which best fits your needs. Charging regularly to 100% is not recommended if you don’t need the range. Some people on this board think this kind of
detail is overly anal and trust that LG/GM designed the batteries to take whatever you throw at them. I prefer to follow the science because the manufacturer just needs to get you past the warranty period.

 

[p7wang]

I think 0% is actually 10% and 100% is actually 90%. So, 75%-25% would mean keeping the car between 17 bars and 4 bars.

I would think 50 miles range is at 25% true SOC. I guess recommendation is not to keep it in that low state long. Charge up to 67%/72% soon.

 

[GJETSON]

I think 0% is actually 10% and 100% is actually 90%. So, 75%-25% would mean keeping the car between 17 bars and 4 bars.

At least for our Bolt, the DIC vs RAW buffer is less than half of what you claim.

 

[p7wang]

OK, thanks for the readings. I guess this is closer then.

 

[RichardC]

OK, thanks for the readings. I guess this is closer then.

View attachment 28102

Interested where this chart comes from p7wang.

 

[p7wang]

Interested where this chart comes from p7wang.

I made it on Google Sheets based on various inputs. Looks about right?

 

[Packard V8]

This topic has been discussed a hundred different threads in a thousand different ways, to no data-based conclusion. A search here will reveal I've repeated a number of times the information directly from a Bolt engineer.

The short version, "The prime directive was to make the Bolt system idiot-proof. In anything which could be considered normal road use, there is nothing the user can do to improve or degrade the battery life. My personal recommendation is just plug it in every night and don't think about it."

jack vines

 

[Vertiformed]

To echo @Packard V8, there is no evidence any Chevy Bolt has suffered due the owner's choices with regard to charging it. There are Bolts with over 100,000 miles that have seen lots of DCFC charging and many deep discharges and have modest battery degradation.

If you didn't worry about looking after the catalytic converter in your fossil-fuel car, probably best not to worry about your Bolt's battery.

But sure, if you want to keep your Bolt for 30 years and drive it 500,000 miles, feel free to adopt whatever battery babying strategy makes you happy. And to that end, I have a suggestion for prolonging your battery life:

Take the car, discharge the battery to 40%, and place your Bolt in a refrigerated storage facility. Disconnect the 12 volt battery. Do not drive it. Every couple of years, perform the usual maintenance you would on a stored vehicle and drive it a little, perhaps 100 miles or so, returning the battery charge to 40% when done.

Follow this regimen, and in 30 years, your car will be ready with maximal range to tackle some real road trips! (Assuming it is compatible with the 500 kW CSS-5 charging stations on the route, of course, and that human-driven vehicles are still allowed on the interstate.)

 

[RichardC]

To echo @Packard V8, there is no evidence any Chevy Bolt has suffered due the owner's choices with regard to charging it. There are Bolts with over 100,000 miles that have seen lots of DCFC charging and many deep discharges and have modest battery degradation.

If you didn't worry about looking after the catalytic converter in your fossil-fuel car, probably best not to worry about your Bolt's battery.

But sure, if you want to keep your Bolt for 30 years and drive it 500,000 miles, feel free to adopt whatever battery babying strategy makes you happy. And to that end, I have a suggestion for prolonging your battery life:

Take the car, discharge the battery to 40%, and place your Bolt in a refrigerated storage facility. Disconnect the 12 volt battery. Do not drive it. Every couple of years, perform the usual maintenance you would on a stored vehicle and drive it a little, perhaps 100 miles or so, returning the battery charge to 40% when done.

Follow this regimen, and in 30 years, your car will be ready with maximal range to tackle some real road trips! (Assuming it is compatible with the 500 kW CSS-5 charging stations on the route, of course, and that human-driven vehicles are still allowed on the interstate.)

Well, snarky is as snarky does. Before we get up from ROFL just remember engineers form GM are obviously going to say crap like that. They also told you Chernobyl is safe, the bridge in Morindi Italy was not going to collapse and don’t worry about getting in a rear end collosion in your Ford Pinto.
The bottom line is Li-ion battery technology In EVs is new to many people and they just want to understand and do the right thing. Since some of you base your knowledge about what one Engineer said or some anecdotal evidence about Bolts going 100k miles doesn’t by any means you grasp or understand the complex science and chemistry of EV batteries nor do you need to try to make the rest of us feel foolish to ask questions. If you can’t be patient, maybe just stay away from the conversation.

 

[Vertiformed]

Well, snarky is as snarky does. Before we get up from ROFL just remember engineers form GM are obviously going to say crap like that. They also told you Chernobyl is safe, the bridge in Morindi Italy was not going to collapse and don’t worry about getting in a rear end collosion in your Ford Pinto.

This is specious reasoning. Just because you can cite examples of engineers being wrong or corporate malfeasance doesn't mean that every statement from an engineer is false or that every action by a corporation is disingenuous.

The bottom line is Li-ion battery technology In EVs is new to many people and they just want to understand and do the right thing.

And for 99% of people, the right thing appears to be quit worrying, go worry about something else, something that actually matters.

FWIW, I have read a bunch about Li-ion batteries, likely more academic papers than most people here, and I've done a bunch of back-of-the-envelope calculations. For me, 100,000 miles is fewer than 500 full-discharge equivalent cycles. Go back to the literature and see what that means.

 

[Lin19687]

Just drive it like you stole it like I do here in N.E.

 

[Wavelet81]

An engineering title doesn’t mean your the end all of things. This thread’s title is best practices. Assuming everything has been accounted by the engineering staff is like assuming everything thrown at the wall will stick. We live in the real world were companies work off the rule of averages. I run my cars into the ground. My last vehicle was a Nissan Frontier from the year 2000. There are best practices and quarks with any vehicle and assuming you can rely on the manufacturer engineering staff for all aspects is just ignorant.

 

[Vertiformed]

assuming you can rely on the manufacturer engineering staff for all aspects is just ignorant.

And assuming that random forum posters on the Internet “know better” is what gets you things like the anti-vaxxer movement or chemtrails folks.

 

[Lin19687]

Seriously here in NE you BETTER have it charged up as you never know where you need to go and IF there is a faster charger to 'fill' it up.

BTW, Slow charging does NOT ruin the batter. Many say that the DC charging all the time is............. I personally don't see that and really you will have this car for so long before the battery puuts out

 

[RichardC]

And assuming that random forum posters on the Internet “know better” is what gets you things like the anti-vaxxer movement or chemtrails folks.

And you are not a random internet poster? I too have read numerous articles and watched videos from battery experts and scientists and conclusively see that you can be hard on a lithium battery or do some simple things that are easy to incorporate that give you peace of mind that your are taking care of an expensive investment. If you have money to throw away after 100,000 miles, well then good for you. Some of us do not. I also wear slippers around the house and guess what, my socks last for years and years. Shame on me.

 

[Packard V8]

I too have read numerous articles and watched videos from battery experts and scientists and conclusively see that you can be hard on a lithium battery or do some simple things that are easy to incorporate that give you peace of mind that your are taking care of an expensive investment. If you have money to throw away after 100,000 miles, well then good for you. Some of us do not.

I've seen no evidence the YouTube click-bait experts know anything about the Bolt battery and its management system. Yes, the Bolt has a LiOn battery pack, but not same-same charging and management system as a laptop or hand tool. Since it is new technology, since it has little in common with anything on which these internet experts have first hand experience, their suggestions are just as likely to be wrong 100,000 miles from now as they are to have provided any means of prolonging battery life. Since there's no real data on maximizing Bolt battery life, it's moot.

jack vines

 

[RichardC]

I guess these people know nothing about EV batteries: 10 Tips to Extend the Life of Your EV Battery | ClipperCreek

Or this newsletter: Top 5 Tips to Maintaining EV Battery Life

And this is truly click bait: What can 6,000 electric vehicles tell us about EV battery health? | Geotab

So sorry to waste your time with this:

I never claimed to be an expert but to assume that I equate laptop batteries and click bait videos with what I hope can be an intelligent discussion material is what a troll does. Also posting ”funny stories” about putting your car into a freezer and removing it years later doesn’t further smart discourse. Like it’s said, if you can’t say something nice, maybe you should say nothing at all.