[mnx5er]

I'll admit to being surprised when after buying my iX and learning that BMW sets the maximum charge to 80%. They even talk about the 80/20 recommendation in the manual. I know this has been discussed in the forum, but I think there are other angles and issues with this.

First - BMW should admit to this at the point of sale and even put it on the sticker. Yes, most EV makers have the same issue, but BMW could have used a larger battery to add more buffer.

The real problem with this is in frozen Minnesota. We are in the 40s in the morning now and I am seeing the range drop. That was to be expected, I figured a 30% dropoff for range as we get to 20 and below. Saw this with my EV6.

But when I do the math, it becomes concerning for real use of the iX.

I normally would get around 310 miles on a full charge here (100%). In the winter that drops down to around 217. The 80/20 recommendation allows me 60% of that or 130 miles.

130 miles isn't much. Yes I can commute, but many other things I do in a day go over that. It also keeps the iX pretty close to home since the charging infrastructure isn't great outside of metro areas.

Seems that BMW needs to be more honest about this. At least tell me the projected degration of using 100% of the battery.

Sorry for the rant, but the colder weather had me doing math. Starting to think it may be best to go back to the ICE X5.

[VirtualGuitars]

Originally Posted by mnx5er

I'll admit to being surprised when after buying my iX and learning that BMW sets the maximum charge to 80%. They even talk about the 80/20 recommendation in the manual. I know this has been discussed in the forum, but I think there are other angles and issues with this.

First - BMW should admit to this at the point of sale and even put it on the sticker. Yes, most EV makers have the same issue, but BMW could have used a larger battery to add more buffer.

The real problem with this is in frozen Minnesota. We are in the 40s in the morning now and I am seeing the range drop. That was to be expected, I figured a 30% dropoff for range as we get to 20 and below. Saw this with my EV6.

But when I do the math, it becomes concerning for real use of the iX.

I normally would get around 310 miles on a full charge here (100%). In the winter that drops down to around 217. The 80/20 recommendation allows me 60% of that or 130 miles.

130 miles isn't much. Yes I can commute, but many other things I do in a day go over that. It also keeps the iX pretty close to home since the charging infrastructure isn't great outside of metro areas.

Seems that BMW needs to be more honest about this. At least tell me the projected degration of using 100% of the battery.

Sorry for the rant, but the colder weather had me doing math. Starting to think it may be best to go back to the ICE X5.

I’m trying to understand what you’re saying. This is nothing specific to the BMW, but it’s always best to charge the batteries to about 80% to manage the performance and capacity over the life of the battery. Most dealerships I have dealt with won’t even let the vehicle leave unless it’s charged to 100% including service appointments. You can change this from the My BMW app or from the vehicle whenever you want.

Personally, I charge mine to 80% unless I’m going out of town and don’t even bother plugging it in until it gets down to at least 20%.

[FultonMDUSA]

Charging to 100% is perfectly fine if you're going to then immediately use the charge. I believe the logic behind the chemistry is that if you keep it above 80% for an extended time, then the battery will begin to irreversibly discharge with side reactions. If it discharges with the primary reaction (i.e. you're using the battery), you should be fine.

Same with discharging. Discharge it to zero, but then charge it up immediately to the 20-80% charge. Don't leave it discharged for an extended period under 20%.

If I know I'm going to drive far enough during the day to use at least 20% of the battery, I will charge it to 100% the night before. Likewise, arrival at home under 20% gets an immediate recharge.

[VirtualGuitars]

Originally Posted by FultonMDUSA

Charging to 100% is perfectly fine if you're going to then immediately use the charge. I believe the logic behind the chemistry is that if you keep it above 80% for an extended time, then the battery will begin to irreversibly discharge with side reactions. If it discharges with the primary reaction (i.e. you're using the battery), you should be fine.

Same with discharging. Discharge it to zero, but then charge it up immediately to the 20-80% charge. Don't leave it discharged for an extended period under 20%.

If I know I'm going to drive far enough during the day to use at least 20% of the battery, I will charge it to 100% the night before. Likewise, arrival at home under 20% gets an immediate recharge.

DC fast charging to 100% on regular basis will hurt the battery’s overall capacity over AC charging to 100%.

[Road Trip]

Yep, we EV’s owners have to plan. Even plug in hybrid owners do some planning, e.g., just day before yesterday, had 26 miles range left but using 16 to get groceries so no need to charge up. But when I got home yesterday from the store, plugged it in to full charge for today going to use all of its 42 mile range up.

Not exactly the same of course due to gasoline tank back up, but I enjoy planning and thinking ahead — though more important with a pure EV by far. Then again with about 300 miles iX range, over 200 in the dead of winter, I would sometimes go over a week (work at home; wife retired), without plugging it in even once.

So nice my “gas station” except for road trips is located within my garage…. Clean restrooms, refrigerator to raid without cost, and so many other benefits other than increasing challenges with public gas stations. Lots of benefits to EV life.

[Paladin1]

As above. High capacity EV batteries have now been around for awhile, with extensive field testing, and turns out they last longer than originally predicted as far as retaining capacity. A lot longer. Normal use still applies for Li-ion batteries as far as "things not good for them," including as noted retaining a 100% charge for a length of time, but probably charging to 100% when you need it (as in Winter), then using it will likely degrade the battery very little from the expected drop-off (which BMW says is 30% or less over 8 years, likely a lot less).

[ricerboi]

You can just charge to 90-95%. It will be fine. Don’t worry about the 80% preset. I echo what others say about it ok at 100% when AC charging and using it right away. For example you can set charging target at 95-100% right at the departure time of for example, 8am. That way the car won’t start the charge until just late enough where it hits your charging target right before you leave and you minimize damage to the battery.

Oh and if you’re leasing, you really shouldn’t care just charge to 100% every day. Possibly bad 8-10 years down the road but you won’t notice it the 3 years you’re leasing.

[Pictor]

Since you say you have (had?) an EV6 then it's the same issue just with a bigger battery in the iX and better thermal management. You could consider an EV with an LFP battery and charge to 100% with no problem but you're also moving to a less energy dense battery when compared to an NMC battery. Personally, I would prefer to have the extra capacity of the NMC battery for the limited times I need it.

Charging to 100% is okay when needed assuming you're not letting the car sit at that SoC and the same goes for going below 20%. When I do long road trips I charge to 100% and go down to 5-10% before charging but the car won't stay at those extremes for more than an hour or two. The majority of time I keep the car between about 30%-60%. For winter, you can also consider preconditioning the car for departure which will help quite a bit.

[FultonMDUSA]

Originally Posted by VirtualGuitars

DC fast charging to 100% on regular basis will hurt the battery’s overall capacity over AC charging to 100%.

It looks like past 83% the charge rate is 50 kW, and then drops drastically again at 97%.

I would hope the DC charging curve, which is controlled by the vehicle, is engineered for battery protection. Then again, it's always possible the marketing folks were able to override the warnings of the warranty actuaries.

[ricerboi]

It’s a bit different for everybody regarding charge rate.

Here’s 1 night where I went from 6%-99% at a DCFC (split in 2 sessions). Nobody waiting at EA so I figured I would top off.

I actually get 50-70kW above 80% all the way to 99%, and after about 1 minute it will drop to 25kW which is when I unplug.

I’m avoiding installing the AC charger at home until my free charging plan runs out in August. Costs me $32-$50 to charge 100kWh at home so it’s worth the hassle of DCFC until I really do have to pay since I charge 1500-2500kWh a month.

[Road Trip]

Thanks for all the good information above. Quite a bit of details on battery degradation on the below Tesla oriented video. Of note however is that Toyota just raised its battery warranty on its plug in hybrids from 8 years and 100,000 miles to now 10 years and 150,000 miles.

[BMWEVGuy]

mnx5er Preconditioning the car is very important so that battery is warm for your drive and does not starts depleting from State of Charge as soon as you start your ride.

Also, please keep your car in your garage, it is better than leaving it outside in the open.

Hope you got Radiant heating package, use that along with steering heat and may be some warm clothes (like a sweater or jacket). That way you can keep your HVAC heating to a low levels or may not require it at all. --> Salesman at BMW dealership told me about this trick. A current owner can perhaps corroborate this one.

Besides this drive at a lower speed without accelerating much.

Lastly you should be thankful you are not a EQS SUV or Sedan owner. It does not have a heat pump so the owners in cold climate will have a lot of fun (or frustration)

[Zinedine]

Originally Posted by ricerboi

You can just charge to 90-95%. It will be fine. Don’t worry about the 80% preset. I echo what others say about it ok at 100% when AC charging and using it right away. For example you can set charging target at 95-100% right at the departure time of for example, 8am. That way the car won’t start the charge until just late enough where it hits your charging target right before you leave and you minimize damage to the battery.

Oh and if you’re leasing, you really shouldn’t care just charge to 100% every day. Possibly bad 8-10 years down the road but you won’t notice it the 3 years you’re leasing.

I have my departure time set for 7am.
But the car charges to the charging target as fast as it can depending on what kW its getting.
I have never seen it adjust charging time so it can reach the charging target and the set departure time.

Am I missing something? maybe some option needs to be enabled?

While I do agree with everyone saying not to keep the battery below 20% or above 80% over an extended period, it would be good to know what everyone means by an extended period. An hour or 2?
10+ hours? or are we talking days?

[mnx5er]

Originally Posted by FultonMDUSA

Charging to 100% is perfectly fine if you're going to then immediately use the charge. I believe the logic behind the chemistry is that if you keep it above 80% for an extended time, then the battery will begin to irreversibly discharge with side reactions. If it discharges with the primary reaction (i.e. you're using the battery), you should be fine.

Same with discharging. Discharge it to zero, but then charge it up immediately to the 20-80% charge. Don't leave it discharged for an extended period under 20%.

If I know I'm going to drive far enough during the day to use at least 20% of the battery, I will charge it to 100% the night before. Likewise, arrival at home under 20% gets an immediate recharge.

This is great information - thank you. My use case is that I always drive it after charging and will burn off around 20% of the battery. So if I can use 100% in the winter, that would really help.

[mnx5er]

Originally Posted by VirtualGuitars

I’m trying to understand what you’re saying. This is nothing specific to the BMW, but it’s always best to charge the batteries to about 80% to manage the performance and capacity over the life of the battery. Most dealerships I have dealt with won’t even let the vehicle leave unless it’s charged to 100% including service appointments. You can change this from the My BMW app or from the vehicle whenever you want.

Personally, I charge mine to 80% unless I’m going out of town and don’t even bother plugging it in until it gets down to at least 20%.

The Minnesota winter penalty is what makes this tougher. During the summer 80% has been more than fine and I have been doing exactly what you describe.

In Minnesota the last thing you want is to run out of battery in the winter (ditto with gas). Gets too damn cold and for me I like to have more range available all winter than what 80% would offer.

While I understand that 80% is ideal for batteries, I still pose the question on why manufacturers do not build in a larger buffer so the consumer doesn't have to worry about it. Obviously the answer is cost. I can't imagine anyone with an ICE vehicle being happy that they should only fill their gas tank 80% of the capacity.

Funny part of this, when I bought the iX, the dealer charged it to 80%. I saw the lower range on it when I drove it off the lot and was scratching my head. Figured it out soon enough.

[mnx5er]

Originally Posted by BMWEVGuy

mnx5er Preconditioning the car is very important so that battery is warm for your drive and does not starts depleting from State of Charge as soon as you start your ride.

Also, please keep your car in your garage, it is better than leaving it outside in the open.

Hope you got Radiant heating package, use that along with steering heat and may be some warm clothes (like a sweater or jacket). That way you can keep your HVAC heating to a low levels or may not require it at all. --> Salesman at BMW dealership told me about this trick. A current owner can perhaps corroborate this one.

Besides this drive at a lower speed without accelerating much.

Lastly you should be thankful you are not a EQS SUV or Sedan owner. It does not have a heat pump so the owners in cold climate will have a lot of fun (or frustration)

Thanks, I keep it in the garage but do not have the radiant heat option. Preconditioning makes total sense and is easy to do.

No desire to run the temp cooler in the car, not at $96K. I like my creature comforts and at times wonder if the X5 50e is the better solution.

[GOLFFRR]

that cold weather really impacts the range. 130 miles? wow

[NomoTesla]

Originally Posted by mnx5er

I'll admit to being surprised when after buying my iX and learning that BMW sets the maximum charge to 80%. They even talk about the 80/20 recommendation in the manual. I know this has been discussed in the forum, but I think there are other angles and issues with this.

Tesla recommends 90%, but 90%-100% takes as much time as 20%-80%. The same goes for BMW. If you are charging at home then this is not an issue, as you have time overnight to charge as high as you wish.

[BMWEVGuy]

mnx5er Please see these two videos (may be ask this owner, he seems responsive and has responded recently):

BMW iX How much range do you lose in the snow?

BMW iX How much range do you lose driving like a maniac in cold weather

[admranger]

How long are you keeping the car? It has a long battery warranty. Just ram it full in the winter. Having grown up in a suburb of MLPS, I know the cold. No way I'm only charging to 80% in the winter if I lived up there. Even with the milder winters it's not happening.

If it weren't for my severe snow allergy, I might consider moving back there.

[ggalanis]

Originally Posted by mnx5er

I'll admit to being surprised when after buying my iX and learning that BMW sets the maximum charge to 80%. They even talk about the 80/20 recommendation in the manual. I know this has been discussed in the forum, but I think there are other angles and issues with this.

First - BMW should admit to this at the point of sale and even put it on the sticker. Yes, most EV makers have the same issue, but BMW could have used a larger battery to add more buffer.

The real problem with this is in frozen Minnesota. We are in the 40s in the morning now and I am seeing the range drop. That was to be expected, I figured a 30% dropoff for range as we get to 20 and below. Saw this with my EV6.

But when I do the math, it becomes concerning for real use of the iX.

I normally would get around 310 miles on a full charge here (100%). In the winter that drops down to around 217. The 80/20 recommendation allows me 60% of that or 130 miles.

130 miles isn't much. Yes I can commute, but many other things I do in a day go over that. It also keeps the iX pretty close to home since the charging infrastructure isn't great outside of metro areas.

Seems that BMW needs to be more honest about this. At least tell me the projected degration of using 100% of the battery.

Sorry for the rant, but the colder weather had me doing math. Starting to think it may be best to go back to the ICE X5.

I feel this is more on you than it is on BMW or your dealership/salesman since you already had an EV before. The 80/20 recommendation is just that.... A recommendation. If you can stay within that SoC, great. If you need to use more, then use more.

[mnx5er]

Originally Posted by ggalanis

I feel this is more on you than it is on BMW or your dealership/salesman since you already had an EV before. The 80/20 recommendation is just that.... A recommendation. If you can stay within that SoC, great. If you need to use more, then use more.

Kia did not have the recommendation when I bought the EV6. BMW publishes it in their manual and in iDrive. It was nowhere to be found on the sticker or BMW marketing. I hardly even see reviewers discussing it.

Salespeople won’t talk about it. It would hurt sales.

I do not disagree with you that EVs are a paradigm shift in how I should think of a car. But I didn’t walk into this blindly, even my charger installer didn’t mention it and he had done 100s of installs.