[liquidator4711]

For the model S, I used to do 80% during summer and 90% during winter, to get similar ranges over the year.

[Kennethjk]

Originally Posted by exxxviii

You ought to create a poll in the forum to see what most people do.

I charge mine to 90%. My reasoning is that the last 10% gives plenty of buffer for regenerative braking. And that extra 10% (above the traditional 80) gives me an extra few days between charges.

There is a small buffer naturally anyway as it’s useable 105 of a 110 battery, correct? I charge to 80% on both my EVs unless more is needed for a road trip.

Being part of the Mach E forum there are plenty of discussions on battery health. Overall these batteries hold up pretty well and not a tremendous difference no matter how you charge.

But, if I was buying a used EV car, I would rather buy one where the battery was treated gingerly. The reality is that these batteries will last such a long time where most people who are first owners will be on to the next best thing.

[exxxviii]

Originally Posted by NomoTesla

You don't need a buffer for regen, the vehicle behaves the same at 100% as it does at 90%.

A few folks have made this claim, but I have not seen any formal affirmation from BMW. Therefore, it looks like anecdotal claims to me.

Do we know for certain that BMW uses battery capacity above "100%" for regen, if so, how much? Are there heat issues that might prevent BMW from using secret buffer above 100%? Or, is BMW just using blended braking at 100% like other automakers?

[exxxviii]

Originally Posted by Kennethjk

There is a small buffer naturally anyway as it’s useable 105 of a 110 battery, correct?

Probably, but how the car uses it is a total unknown. For example, Consumer Reports recently published their 70 MPH BMW iX range test and got an additional 30 miles after the car read 0%. That could suggest that the BMW iX uses 8% phantom battery capacity on the bottom end of the battery. We have no clue how much buffer might be at the top end and if this is used for regen or totally protected for battery longevity.

[NomoTesla]

Originally Posted by exxxviii

A few folks have made this claim, but I have not seen any formal affirmation from BMW. Therefore, it looks like anecdotal claims to me.

Do we know for certain that BMW uses battery capacity above "100%" for regen, if so, how much? Are there heat issues that might prevent BMW from using secret buffer above 100%? Or, is BMW just using blended braking at 100% like other automakers?

All I know is it just works. Check out Bjorn's charging race between Kia EV9 (800v), Audi Q8 e-tron (400v), Fisker Ocean (400v) and BMW iX (400v). The Kia and Audi beat out the iX by less than a minute. Kia had a 10% smaller battery and the Q8 was showing 40% less range at 100% than an iX.

I noticed the charge rate on the iX dropped significantly at 87% and again at 99%.

[thebishman]

Originally Posted by ricerboi

I was curious (and nervous) myself too as I was completely reckless with charging, although I don’t have a home charger so I’m naturally at 20-80% most of the time.

Just do whatever is convenient, the BMW battery management system has got us covered!

I lose my free EA that I’ve milked for 20+ MWh in 3.5 months 😅 so that degradation will level out at 85-90% the next 2 years.

Ricerboi:

This software is interesting to ‘play’ with, and may well be accurate; time will tell.

But can you tell the hive:

In decent ambient conditions, what range does your iX show at perhaps; 80%; 90% and 100%?

I would be interested to see if those GOM estimates are any different than others.

TIA

[ricerboi]

Originally Posted by thebishman

Ricerboi:

This software is interesting to ‘play’ with, and may well be accurate; time will tell.

But can you tell the hive:

In decent ambient conditions, what range does your iX show at perhaps; 80%; 90% and 100%?

I would be interested to see if those GOM estimates are any different than others.

TIA

100% I’m getting 290-310
90% I’m getting 250-270
80% I’m getting 230-250

I average 2.4mi/kWh for the life of the car so I guess I’m getting 220 miles ish with battery at 92% ish health. I’m changing out my tires soon and the efficiency should improve 3-5% (smaller diameter, lower weight).

[A418t81]

I don’t understand not taking care of a vehicle you drive, lease or otherwise. My iX is the first vehicle I have leased in my life, but I still garage it, and hand wash it. I also limit charging to 80% unless I’m going on a trip. This has never once impacted my use of the vehicle. I guess not I’m pathologic enough to not care about the impact on the subsequent owners down the line.

[Windshieldfarmer]

Originally Posted by A418t81

I don’t understand not taking care of a vehicle you drive, lease or otherwise. My iX is the first vehicle I have leased in my life, but I still garage it, and hand wash it. I also limit charging to 80% unless I’m going on a trip. This has never once impacted my use of the vehicle. I guess not I’m pathologic enough to not care about the impact on the subsequent owners down the line.

You have integrity; a character trait so many lack. Thinking beyond one’s self is a great way to live.

[ix50si]

Originally Posted by drbluedevil

If it's a lease, who cares? You're unlikely to meaningfully degrade your overall charge capacity during your ownership period even with charging to 100% all the time.

When charging to maximum capacity, you will generate more waste heat as the charging efficiency reduces more and more the closer you approach 100% SOC. So if the extra few wasted cents/dollars or the knowledge of the inefficiency is bothersome to you, then cap it at 80%. If you don't care and like starting the day at 100% no matter what, then just go for it.

I cap at 80% because I don't need nearly that much charge, and I usually don't plug in until I'm down to 40 or 50%.

That was my question. What percentage above 80 is best to go to in order to max range and also not waste energy charging? 85, 90, 95?

[Kennethjk]

Originally Posted by ix50si

That was my question. What percentage above 80 is best to go to in order to max range and also not waste energy charging? 85, 90, 95?

I don’t think it matters . Just charge as you need

[Louis_BE]

Originally Posted by ix50si

That was my question. What percentage above 80 is best to go to in order to max range and also not waste energy charging? 85, 90, 95?

When I really need the range I charge typically around 95%, like I stop overnight at 90% and restart it when I get up to 100%, knowing I will never reach 100% and typically it is around 95 to 97%. The benefit is that battery is already a little warmer, so more efficient and not staying at 100% … Even on a long roadtrip that 5% is not gonna make a difference and the charging just before departure probably wins more range due to optimal temperature …

[drbluedevil]

Originally Posted by A418t81

I don’t understand not taking care of a vehicle you drive, lease or otherwise. My iX is the first vehicle I have leased in my life, but I still garage it, and hand wash it. I also limit charging to 80% unless I’m going on a trip. This has never once impacted my use of the vehicle. I guess not I’m pathologic enough to not care about the impact on the subsequent owners down the line.

When you sign your lease, you contractually agree to specific criteria regarding vehicle use, maintenance and repair, and standards for excessive wear (including the size of inevitable dents/scratches, tire tread depth, etc). Nowhere does it specify the manner in which you must charge or discharge the battery. Nobody here is advocating operating the vehicle outside the parameters of its design.

Your claim that frequently charging to 100% signifies a "pathologic" disregard for subsequent owners is absurd. Operating the vehicle within the parameters set by BMW is well within your rights as a lessee. As I said, I charge mine to 80% every few days because I don't need the extra charge and because it's wasteful for me to go over 80% SOC...more electricity is lost to heat charging that way. But if exxxviii or anyone else is more comfortable charging beyond that, then that's their right, and shame on you for suggesting they have a pathologic disregard for the next owner. They owe BMW a vehicle at lease end that either meets a specific set of criteria, or else they must make repairs or pay damages. That's it. They have no obligation whatsoever to the next owner. The next owner can check the battery health at the point of sale (along with anything else about the car) and determine if they want to buy, negotiate, or walk away.

Let's take this beyond battery health. Is it pathologic to drink coffee while driving? After all, spills get into the perforations in the seat and soak a bit into the foam. This hurts the next buyer. How about parking in tight spaces? Those door dings, even if they're within the tolerances of the lease agreement, will certainly diminish the experience for the next owner. Maybe we shouldn't accelerate too hard. All that wear-and-tear adds up and will make for a worse experience for the next buyer. Perhaps we shouldn't have EVs at all unless we live in coastal California, so the battery is never exposed to extreme heat/cold. I'm sure the forum members can come up with thousands of examples of ways to operate these vehicles within the parameters of the lease agreements that might not be ideal for subsequent owners.

[ggalanis]

Originally Posted by ix50si

That was my question. What percentage above 80 is best to go to in order to max range and also not waste energy charging? 85, 90, 95?

Since as you stated you don't care about the long term battery health, charge to whatever you want. You'll probably rarely ever need the extra range the added over 80% SOC gives you but if it makes you happy to see it at 92% at the end of your day instead of 72% and have it back to 100% in the morning instead of 80% then just do it.

You already know it isn't ideal for the battery. How big that degredation effect is is unclear but we know it is not good to do long term. You don't care. That's fine. It is your car after all. Just like some people drive leased cars hard and have no issue pinging it off the rev limiter constantly, and doing loads of launches knowing it isn't good for the car. How much does each launch/revs hitting the limiter damage the engine/drivetrain? Hard to quantify. But we know it isn't good for it. They feel like that's why they pay for it and they do what they want. You should do the same. The difference in energy used to get the equivalent daily charge is not going to be meaningful IMHO.

[Pictor]

Originally Posted by drbluedevil

Is it pathologic to drink coffee while driving?

Yes. This is a rule that also applies to passengers.

[ix50si]

So what would be the highest one can charge above 80 that maximizes available range but doesn’t waste energy loss during charging process?

[exxxviii]

Originally Posted by ix50si

So what would be the highest one can charge above 80 that maximizes available range but doesn’t waste energy loss during charging process?

Im not sure this is known, but it would most likely be the point at which the rate of charge drops from ~11 kW. I’m pretty sure mine stays pegged at 11 kW until 90%, so if there is a point at which it becomes less efficient, it is somewhere north of 90.

[LVBMW]

Originally Posted by ix50si

So what would be the highest one can charge above 80 that maximizes available range but doesn’t waste energy loss during charging process?

Are you talking home charging or DCFC? I don't know that anyone knows the answer to such a specific question.

[Kennethjk]

Originally Posted by exxxviii

Im not sure this is known, but it would most likely be the point at which the rate of charge drops from ~11 kW. I’m pretty sure mine stays pegged at 11 kW until 90%, so if there is a point at which it becomes less efficient, it is somewhere north of 90.

Is it less efficient, meaning losing a larger % of the incoming electricity or just slower?

[exxxviii]

Originally Posted by Kennethjk

Is it less efficient, meaning losing a larger % of the incoming electricity or just slower?

It means losing a larger % of incoming power. There are some fixed losses of charging, so lower incoming rate increases % loss. And there are some additional losses when the battery gets hot, which might be unknowable. But lower rate of charge is a good proxy.

[ix50si]

Originally Posted by LVBMW

Are you talking home charging or DCFC? I don't know that anyone knows the answer to such a specific question.

Home charging

[Kennethjk]

Originally Posted by exxxviii

It means losing a larger % of incoming power. There are some fixed losses of charging, so lower incoming rate increases % loss. And there are some additional losses when the battery gets hot, which might be unknowable. But lower rate of charge is a good proxy.

Will have to take a look at that, possible to point me to any articles on the topic
Thanks