80% charge or 90% charge for daily use?

[Larry Paul]

Larry's post feels like a more realistic way of looking at it...

The United Nations says life expectancy is 72.6 years... Should we all plan our retirement and 401k based on that generic average? Obviously we can do better by drillng down to where we live, gender, habits, health history, genetics, and a whole host of variables - and in the end the doctors will tell you what we now know - eat right, don't smoke and get some exercise.

In EV terms there are parallels - Don't buy a car with an air cooled battery, don't overheat the battery if you live in a hot climate, avoid DC Fast charging, keep the level between (pick your own numbers here) 35 and 75 percent as much as practical, and so on.

You cannot argue that there will always be statistics that can be gathered that will present trends, there will be averages, and half the time you will beat the average and half the time you will not. How you treat your car will have a lot to do with which group you are in. I can tell you this though - in 20 years you can compare the health of Larry's battery (a thoughtfully cared for battery which has been used but not unnecessarily abused/a battery with buffer margins built in and a thoughtful BMS versus the cars with air cooled batteries versus the highly popular brand that encourages owners to beat their batteries to a pulp by trying to wring impossible ranges out of the pack and then fast charging them constantly as though it was good for the car (not naming names Elon), and I think you'll find Larry is absolutely in better shape despite the other cars having had their battery packs replaced at least once in that time period. 20 year old rav 4 with a factory battery going strong - hard to argue with that.

If you are on an Options Lease and returning the car in another 2 years, you may not care, but the same people who change their oil, and transmission fluid, rotate their tires, and put new belts on their cars today at reasonable intervals, are the EV owners of tomorrow who will treat their batteries as Larry thoughtfully describes.

That said - if you need to take a road trip - go ahead and fill her up... it's like that occasional cheeseburger on cheat day - it's not going to kill you. You may just go down to 72.5999 years.

I really like both of those analogies... Average human life span does have significant variables that include how you live, genetics and some luck. Also-the service on an ICE also has a big impact on the life of an engine. I am confident that you can go a long time and only rarely changing your oil on an ICE and filter on a car from new, but I am also confident that if I use good oil and change it every 5K miles my ICE engine would last for many more 10's or 100's of thousands of miles longer and be more reliable because of best practices, however, I will never own an ICE for daily driving again.

I think that best practices are being a bit mindful of charging habits are a solid and proven way to get an EV to last far longer. I also think that not charing it to a higher level than is needed for daily use will make a big difference in the life of a battery pack. I am using both my 23+ years of EV experience and data that backs up what I am saying.

I am not recommending that people inconvenience themselves. I am just stating that for me (and probably most people) that drives typically 40-60 miles (or less) and on some occasions I drive 100-120 miles in a day, I don't need to keep my car charged to be able to go 260-290 miles on one charge every day. After 4+ months of owning the car, keeping the car so I can go 190 miles is plenty and I think the outcome for that will be a much longer battery life. If/when I use the car on a road trip, I will charge it differently, but I don't do road trips unexpectedly or very often from home either these days.

I also know that there is massive DCFC infrastructure around where I drive and if I get in trouble where I need more range, I can stop in and in less than 20 minutes get wherever I need to get to. I have not needed it yet for any daily driving and with my Chevy Bolt I used DCFC exactly zero times in my 55 months of ownership. While I did not ever need DCFC with the Bolt, however, it is nice to know it is there in 2022 with the Mach E. This allows me to keep my pack in a less stressed state and I am confident that it will make my car last for decades longer.

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[TTT]

Anger is also a factor in decreasing lifespan.

I could propose that in 3 years you and Larry both take your cars and pink slips in to have your battery health measured at the same time... is that what you are proposing?

I'm kidding... Geez. Don't charge your epinehrine level up to 90%

In all seriousness - this is a thread where people are asking questions about the long term health of their batteries, and we are fortuante to have a member here that has owned the same EV for 20 years. How many of the first Gen Rav4's are still on the road these days? A couple dozen? How many on a factory battery? How many of those still have 80% capacity?

You can't be annoyed when someone asks what its like to walk on the moon and get annoyed when Buzz shows up to post a reply, and you shouldn't be annoyed with Larry's answers because they don't mesh with your opinions. I will propose by the way that this IS an appropriate analogy: Lets find out - How many First Gen Rav 4's are out there running on factory batteries - Larry probably knows. How many living Apollo Astronauts that have walked on the moon are there today - betcha the numbers are pretty darned close.

So when someone shows up with 20 years of data and a successful outcome lets welcome his reply please, not treat him like a elections official is all.

 

[DevSecOps]

Anger is also a factor in decreasing lifespan.

I could propose that in 3 years you and Larry both take your cars and pink slips in to have your battery health measured at the same time... is that what you are proposing?

I'm kidding... Geez. Don't charge your epinehrine level up to 90%

In all seriousness - this is a thread where people are asking questions about the long term health of their batteries, and we are fortuante to have a member here that has owned the same EV for 20 years. How many of the first Gen Rav4's are still on the road these days? A couple dozen? How many on a factory battery? How many of those still have 80% capacity?

You can't be annoyed when someone asks what its like to walk on the moon and get annoyed when Buzz shows up to post a reply, and you shouldn't be annoyed with Larry's answers because they don't mesh with your opinions. I will propose by the way that this IS an appropriate analogy: Lets find out - How many First Gen Rav 4's are out there running on factory batteries - Larry probably knows. How many living Apollo Astronauts that have walked on the moon are there today - betcha the numbers are pretty darned close.

So when someone shows up with 20 years of data and a successful outcome lets welcome his reply please, not treat him like a elections official is all.

Sometimes you just have to roll your eyes and move on ... you think that some random person on the internet, who isn't in any way qualified to make an assessment on his 20yo battery and what has caused its degradation, is more scientifically accurate than studies by qualified professionals. Also, in the last 20 years battery technology has dramatically improved so comparing them is not even appropriate.

I backed my claims with links to scientific studies. If you don't want to agree with those studies then you can take that up with them.

 

[TTT]

I've heard of Larry. I think there is a reason he went ahead and registered with his full name, he has a reputation that some people respect.

You are correct, however: I don't worry about random people.

 

[Larry Paul]

So you're going to compare a physical life to a material object? My grandfather always said, I'm going to eat to enjoy food, and if I die because of it, at least I lived a happy life.

Your mentality is one of the reasons that we don't have a higher percentage of EV adoption. People don't want to get out a calculator to figure out if they have enough charge to get where they are going tomorrow. We buy material things, such as cars, as a tool to our daily lives. We want them to work without effort. Sure maintenance is maintenance, but that's once a year for most people, it's not a daily chore. If you tell someone on the fence about EVs that they have to keep the battery within certain percentages and calculate their routes you lose them.

Everyone is entitled to do whatever the hell they want, but I'm willing to bet money that after 3 years ownership my reduction in range per mile driven will be less than or equal to someone who drove less and babied the battery. I'll take the stress free option.

Fred: I do generally agree with your statement: "People don't want to get out a calculator to figure out if they have enough charge to get where they are going tomorrow." I don't ever get a calculator out to figure out what I am going to do the next day-or any given day unless I am going on a road trip. I don't think I have ever woken up in the morning and said, hmm...I am going on a road trip unless I had planned to go on a road trip.

One of the most common responses I have had for future EV drivers is:

"Reset your trip odometer every day when you leave the house and see how far you ACTUALLY go in a day, I will bet you find you don't go as far on a daily basis.

Most people do not fill up their ICE after every single drive just incase they could suddenly go 250-400 miles without stopping for gas every single day. Most people fill up when they hit 1/2 or 1/4 tank when the car is down to the last 60-125 miles.

On an ICE people know that they can stop for 10 minutes and fill up at any time.

I am super comfortable with having 190 miles of range every single morning. I am also super comfortable that I can can stop for 20 minutes and get another 50-60+ miles of range or longer if I know I am going a longer distance.

If I am going on a road trip, I will know it in advance and plan accordingly. I will then charge the pack up to a much higher SOC and use DCFC.

But I also know that a higher SOC will degrade the battery faster...and know that I don't want to wear my battery out for no reason at all for what I do 355 days a year.

I have to say, I don't agree with your statement: "Your mentality is one of the reasons that we don't have a higher percentage of EV adoption."

I think if people know they can keep an EV that will do 100% of what they need and the battery can last, there will be a much faster EV adoption.

I know that EV ownership can be a fantastic experience. Few have driven as much as I have on battery power for as many years as I have. Most are new to EV's and the best way to have EV adoption grow is to make sure that people know the best way to treat your battery and car.

Is it identical to an ICE...no is slightly different than an ICE. There are super small tweaks to behavior that will make it a great experience for people.

I know with 100% certainty and 23 years EV ownership for most people for what they do most of the year with a car far superior to an ICE. Will I take road trips in my Mach E. Yes I will, but I typically fly to a different location and rent a car for most of my vacation and work travel. Is an ICE more practical in 2022 for a road trip, probably would have to say yes, but I am not going to drive around for 355 days a year in an vastly inferior ICE for what I may do 5-10 days out of any given year.

I will never go back to an ICE for daily driving.

Can you just drive it and not care about battery life-sure. It works for a while-and if Ford is correct-you can for 100K miles and not lose more than 30% of your range. Then they get to sell you a new car. That is not my plan and for most people they don't need to top off a battery for daily use and never need it.

 

[DevSecOps]

Most people do not fill up their ICE after every single drive just incase they could suddenly go 250-400 miles without stopping for gas every single day. Most people fill up when they hit 1/2 or 1/4 tank when the car is down to the last 60-125 miles.

Because filling with gas takes 5 minutes. If EVs were the same we wouldn't even be having this conversation.

I have to say, I don't agree with your statement: "Your mentality is one of the reasons that we don't have a higher percentage of EV adoption."

I think if people know they can keep an EV that will do 100% of what they need and the battery can last, there will be a much faster EV adoption.

Your looking at this through your eyes and not those of many American workers and rural/suburbanites, like myself, that are taken on a new journey at the drop of a dime. It's 20 minutes to the closest grocery store, 1hr to the closest airport.

One day I might drive 50 miles, another it's 400. I never know where my day will take me. I charge to 90-100% daily because I don't know what will come up. My network is not full of liberal EV enthusiasts, it's quite the opposite. I talk to these people and battery charging is the #1 reason that most people are turned off of EVs. Most love the idea of instant torque and cheap at home charging but, they don't have the time to wait around trying to figure out how long they have to stop for, where to stop or, for that matter, how much to charge to on a daily basis. Most of the men have trucks and the rest are soccer moms, with big SUVs, who never know where the kids need to go to next. Vehicles are tools to many people and they just want them to work. The most recent study I saw was that 65% of new vehicle purchases will be sold within 5 years.

Like I said a few posts back, a lot of this comes down to lifestyle. Where I have an issue is the fear mongering, if you will, about charging a battery. Many people on this forum and throughout the internet tell people "don't charge to 90%-100% or else"... Or else what??? What's the quantitative loss value? They lose an extra 1 mile of battery capacity a year? Is that worth the argument? Is that worth the stress for people? If you want to charge to 70% once a week then do it, but I fundamentally disagree with the notion that EVs shouldn't be charged to 90% daily "or else". I think it's a bad look for EVs and yes it turns people off. 2/3 of Americans won't even have their EV long enough to notice degradation. Even the KBB states that battery degradation is "overstated", which aligns with my observations. The numbers that the KBB state as a "rule of thumb" are 0.25-0.5 per 3/mo and 0.575 per 3/mo depending on the study. The difference therefore, between the first study numbers, is approximately 13 miles over 5 years. How much of that can be mitigated with a different L2 charging scheme is unknown, but I doubt it's by more than 3-4 miles over 5 years. 3-4 miles is not something I'm going to stress over and no reason to impose fear on people.

I DCFC approximately 100kW a week in this car (normally to 90% each stop) and I believe that my degradation is on par with anyone else at 24k miles and I would even encourage anyone who has that many miles to post their SOH%. My guess is that I'm within 0.5% SOH as someone who hasn't ever used a DCFC or charged to 100% regularly.

@mkhuffman what is your millage and SOH? I know you have a reader.

In closing, I want to make it clear. Every study that I've seen says that high and low charge do degrade the battery over time, especially when you leave it sitting within that range. I'm not arguing that. I have issue with the minuscule amount of degradation and the fear that people impose on EV owners. My original point was there's other things more important to worry about than your daily L2 charging habits. Also, my brain is data driven. I used reputable research studies, which I cited, and values from my car to calculate the difference. I respect your opinion, but your claim of "my experience" doesn't give me quarantine values. If you can prove to me with, with scientific fact, that by charging 40-70% only when needed is substantively better (more than a mile/two a year in gain) than 90% daily, I'll gladly eat crow. Also, in California battery warranties are 10yr/150k by state law.

 

[JSeis]

I drive slightly under 90 miles daily & charge to 90% 5 days a week. In the winter I precondition and the garage never gets much below 40 F. I average about 213 miles of 90% charge this time of year. In the winter that’ll drop to about 165 if temps are 29-37 F.

Nice morning views!

 

[Larry Paul]

I agree with you there can be turn offs for people on EV's, however, the vast majority of the noise on EV's is filled with misinformation. Many people think you MUST replace you battery at 5 years....and it will cost more than the cost of the car to do it. I think that is part of what we are both (and others) are trying to get out there...that is a BS article. This is one of the reasons that I am still driving my 20 year old EV with 20 year old batteries. I just is not true.

When I first got an EV in January of 1999, we thought the EV would be our "third car" that we would use on occasion. We discovered instantly, this was not the case and we both were always wanting the EV.

As I have said...for most potential EV drivers, I ask:

"Reset your trip odometer every day when you leave the house and see how far you ACTUALLY go in a day..."

Knowing their answer, it gives a direction for what may work best for their lifestyle. And I think we agree that modern EV's can work for everyone.

For MOST people they don't suddenly wake up and go 50 miles one day and randomly, on a different day go 400 without any notice or planning, however, the good news is for people like you, an EV is an option now where it was not before. DCFC is a great option and if you drive a great deal living with x% per year is going to be perfectly acceptable.

I think if I were getting an EV specifically for the long range driving, I would probably not get a Mach E. I would get a Tesla, Kia EV6, Ionic 5, Genesis GV60 or Porsche Taycan...(because they all have superior DCFC capability). I got the MME GT PE for other reasons than just range and DCFC speeds...like I really like the way it drove as well as the functionality/practicality/styling, performance, and just overall excellent driving experience.

My whole point is I don't think a majority of people end up actually drive the kinds of ranges you drive....and for those people (like you), that may be a sizable minority-they DO have an option.

Just realizing that range anxiety is not a thing to worry about - because they don't go as far as they think that they do AND if they do go long distances, there are EV options with long ranges and DCFC is a great option to enable a quick boost of range.

For people that think that they need a large driving range on a daily basis - but don't need it, there are great options for them too-and you can get a car that that will cover more than their needs and also it can last for years longer than they thought because there is a way to get even a longer life from the batteries and have it cover 100% of their needs.

For people that KNOW they don't need a long range car, then there are tons of EV options for what works best for them.

We are both trying to reach people who are considering getting an EV and the great news is modern EV's can work for everyone for different needs and at different budgets, desires and many other factors on why people choose whatever car they choose. Every month there are new options.

I am glad there are choices that can work for you AND for me.

 

[mkhuffman]

@mkhuffman what is your millage and SOH? I know you have a reader.

My HVB Age is 11.5 months, I have 14,441 miles (no HVBJB failure yet!!!) and HVB SOH is 96%.

I don't normally monitor SOH so I don't know what it was new, or how much it has changed over the last few months. It is interesting though, so I will start tracking to see how it changes. I suspect that number is an approximation, and would not be surprised to see it go up depending on the day.

I have not used all my free DCFC yet, so DCFC is rare considering I have had the car for almost 10 months. Most L2 charging is at 48 Amps, with some at 40 Amps.

I showed you mine, what is yours, oh vast traveler and DCFCer?

 

[mkhuffman]

DCFC is a great option and if you drive a great deal living with x% per year is going to be perfectly acceptable.

I agree but previously you have mentioned a couple times how great the infrastructure is. I guess it is great where you live, but it is not great here. And charger congestion is a huge problem. You cannot count on a quick 20 minute charge any more. You have to assume there will be people waiting for a charger, which means your "20 minute" charge turns into 40 minutes, or an hour.

Anyway, I tend to agree with Todd. If you buy a car that advertises a certain capability, you should not worry about it when you use that capability. I keep my car between 80% and 90% when in town, and I am not worried that it is damaging the battery to do that.

And I am not willing to increase my stress worrying about damage because I am not keeping the battery at 50% SOC all the time. Because really that is what you should do to minimize damage. Never let it get below 40%, and never let it get above 60%. Never DCFC, and only charge using the 24 Amp 240V. Never floor it either, because you know WOT draws a ton of current and puts stress on the battery. And never go over the speed limit, because that will stress the battery more.

Sorry, I am not doing all those things. And Todd is right: most normal people don't want to do those things. They just want to get from point A to point B. Like my wife.

And I am not a normal person. I do think about the things you think about. After all, I am not charging to 100% daily. And I participate in this forum. We forum people are not the normal car buying public. We know more, and we are willing to do more.

It is fine for people to charge to whatever level they are comfortable doing, without worrying about damaging the battery.

By the way, Ford has an entire BMS that should do the thinking for us. We should follow the guidance in the owner's manual, and then let the BMS take care of battery health. And then just enjoy life. And enjoy are cars. Man, my car is fun, especially when I damage the battery with a few WOTs here and there. ?

 

[Larry Paul]

I agree but previously you have mentioned a couple times how great the infrastructure is. I guess it is great where you live, but it is not great here. And charger congestion is a huge problem. You cannot count on a quick 20 minute charge any more. You have to assume there will be people waiting for a charger, which means your "20 minute" charge turns into 40 minutes, or an hour.

Anyway, I tend to agree with Todd. If you buy a car that advertises a certain capability, you should not worry about it when you use that capability. I keep my car between 80% and 90% when in town, and I am not worried that it is damaging the battery to do that.

And I am not willing to increase my stress worrying about damage because I am not keeping the battery at 50% SOC all the time. Because really that is what you should do to minimize damage. Never let it get below 40%, and never let it get above 60%. Never DCFC, and only charge using the 24 Amp 240V. Never floor it either, because you know WOT draws a ton of current and puts stress on the battery. And never go over the speed limit, because that will stress the battery more.

Sorry, I am not doing all those things. And Todd is right: most normal people don't want to do those things. They just want to get from point A to point B. Like my wife.

And I am not a normal person. I do think about the things you think about. After all, I am not charging to 100% daily. And I participate in this forum. We forum people are not the normal car buying public. We know more, and we are willing to do more.

It is fine for people to charge to whatever level they are comfortable doing, without worrying about damaging the battery.

By the way, Ford has an entire BMS that should do the thinking for us. We should follow the guidance in the owner's manual, and then let the BMS take care of battery health. And then just enjoy life. And enjoy are cars. Man, my car is fun, especially when I damage the battery with a few WOTs here and there. ?

I did say that I have infrastructure around where I live. I know it is not built up everywhere (and thought I had said that).

I also agree you should not have to think about it or be stressed at all. My wife has not pumped gasoline once in the last 20 years. She never thinks about it. Neither do I.

Either way, you can just drive the car like a normal car. For our lives, we have found that cars with 100 miles of range work for our lives. Owning a car that can go close to or beyond 300 miles is much more than I need for a daily basis. Since it is, I have the option of having a fun to drive car that I have the option that I can also extend battery life.

The great thing is today that there are EV’s can work for about everyone. The BMS on the cars is great and my main point is we are not talking about the degradation of an “generic” ev. Every EV has a unique design and modern BMS and battery cooling design can enable a slower degradation. There are things you can do that slow that degradation down further. For me - having us drive for 338K miles in over 23 years this works and I don’t think about it. I think everyone can find a method that eliminates thinking about it. It should not stress you out, nor be hard- and I think that is one point that I hope we agree on.

 

[fpasta]

Interesting arguments from both sides.

When they but a DCFC station down the street where I live is when I decided to get an EV amongst other main reasons too.

I was thinking, that will be the way I charge 100% of the time up to 100% charge, I won't care. After I got the EV. Not even a week gone by I was already scheduling a contractor for a 14-50 outlet. Now I charge anytime any percent I want.

Once everyone has greater accessibility alongside the technology of charging and batteries that can improve will we care less.

 

[kennethjk]

Some people baby their ICE cars, change oil every 3 months, rotate tires etc etc. usually in the hope of their car lasting longer. Those same people would find it helpful to understand something about their battery lifespan Since it’s relatively new to them.

other people drive their ICE cars to the limit, why?, some feel that since they lease it , any problems will be the next persons problem, others because they just love to drive.

different strokes for different folks, having the right knowledge with either ICE or EV will help some people just feel better about their decisions.

I drive my 911 much different than the MME and treat them differently also. Works for me but maybe not others and that’s ok too.

 

[iaming]

What's best for the driver varies a lot, but can we conclude what's the best for the car?

I don't think charging daily is the best for the car.

When should I charge is the best choice for the car? Say 20/30miles per day, 4/5 days per week.

 

[RickMachE]

What's best for the driver varies a lot, but can we conclude what's the best for the car?

I don't think charging daily is the best for the car.

When should I charge is the best choice for the car? Say 20/30miles per day, 4/5 days per week.

Daily. What you think I think is wrong.

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