[NomoTesla]

Originally Posted by bmwix1

Regardless of how you charge or discharge the battery, it doesn't degrade the battery that too much theoretically. The unmanaged heat during the chemical reaction will cause permanent damage. So the longer your charge cycle is, the likelihood of excessive heat to be generated during charging is high. Battery management system can only do so many things at once. It won't dispatch the heat as if cooling overclocked CPU with liquid nitrogen. So in reality, charge and discharge in small cycles are better to enlong battery life. If you really have to charge to 100% for a long trip, go ahead. But try your best not to drain the battery to 0%. I would personally set the target at 95% in this scenario, so even BMW software shits up, there is still some room for margin of errors. Of course, I will AC charge when the battery is drop below 15% during a long trip if no DC charging station can be found for a long stretch as the last resort.

100%. This is why it's best to charge on AC at much lower current than DC fast charging. It's the heat.

[juzza1234]

Originally Posted by VirtualGuitars

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

What’s the logic behind this? Whether you plug in to an AC charger or a rapid DC charger, the batttery only uses DC to charge, using the onboard inverter to convert an AC connection to DC before it gets to the battery? Is it solely the higher DC values for the ultra charger?

[KRS_SN]

Originally Posted by bmwix1

Regardless of how you charge or discharge the battery, it doesn't degrade the battery that too much theoretically. The unmanaged heat during the chemical reaction will cause permanent damage. So the longer your charge cycle is, the likelihood of excessive heat to be generated during charging is high. Battery management system can only do so many things at once. It won't dispatch the heat as if cooling overclocked CPU with liquid nitrogen. So in reality, charge and discharge in small cycles are better to enlong battery life. If you really have to charge to 100% for a long trip, go ahead. But try your best not to drain the battery to 0%. I would personally set the target at 95% in this scenario, so even BMW software shits up, there is still some room for margin of errors. Of course, I will AC charge when the battery is drop below 15% during a long trip if no DC charging station can be found for a long stretch as the last resort.

Interesting point...I assumed limiting charging frequency was the key ie topping up from 30-80 every 2-3 days than 60-80 everyday. Your post suggests better to do the latter.

[m3_08]

i'm on the bad side of this discussion: I charge X5 45e every day to 100% and after 4 years electrical range shows the same numbers.
The same I do with Tesla MYP - charge weekly to 100% and the range the same after 2 years.
Only negative factor there is to get from 80 to 100% takes longer.

[drbluedevil]

Originally Posted by m3_08

i'm on the bad side of this discussion: I charge X5 45e every day to 100% and after 4 years electrical range shows the same numbers.
The same I do with Tesla MYP - charge weekly to 100% and the range the same after 2 years.
Only negative factor there is to get from 80 to 100% takes longer.

Yeah, damage doesn't seem to be an issue charging fully, especially when done with home charging.

It's more about the inefficiency of doing so; you'll waste more electricity/money per unit of energy stored getting those last available chemical reactions to occur to get to 100%. So if you don't need to charge fully, why do it? If the range anxiety would kill you, then sure...

[NomoTesla]

Originally Posted by juzza1234

What’s the logic behind this? Whether you plug in to an AC charger or a rapid DC charger, the batttery only uses DC to charge, using the onboard inverter to convert an AC connection to DC before it gets to the battery? Is it solely the higher DC values for the ultra charger?

Heat.

[bmwix1]

Originally Posted by KRS_SN

Interesting point...I assumed limiting charging frequency was the key ie topping up from 30-80 every 2-3 days than 60-80 everyday. Your post suggests better to do the latter.

Instead of 80 -> 30 -> 80, 50% dis/charging cycle,
Perform small dis/changing cycles between 25~35%
discharge: 80 -> 45
charge: 45 -> 70
discharge: 70 -> 35
charge: 35 -> 60
discharge: 60 -> 30
charge: 30 -> 65
discharge: 65 -> 35
charge: 35 -> 70
discharge: 70 -> 45
charge: 45 -> 75
discharge 75 -> 50
charge: 50 -> 80
repeat

It will prolong the battery.

Regen braking is basically fast charging battery at frequent but very small cycle and short session. It doesn't hurt the battery.

[Salespunk]

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)

Actually the EQS SUV does have a heat pump. The EQS Sedan did not have one originally, but they have announced it will be standard going forward.

For the OP, why do you need 100% and is it a daily thing or just every few weeks for a trip? We charge my wife's EV to 100% about once a month for trips and not stressed about it at all. Not a daily thing and we don't let it sit at that level.

[shoot_the_goalie]

I just keep it simple. In general charge to 80% (unless I'm doing long distance) and charge again when it drops between 20-30%. I feel it's not worth it to micromanage my charging habits just to save a few % points in long term battery capacity.

[BMWEVGuy]

Originally Posted by Salespunk

Actually the EQS SUV does have a heat pump. The EQS Sedan did not have one originally, but they have announced it will be standard going forward.

For the OP, why do you need 100% and is it a daily thing or just every few weeks for a trip? We charge my wife's EV to 100% about once a month for trips and not stressed about it at all. Not a daily thing and we don't let it sit at that level.

2023 EQS SUV does not have a heat pump. (EQE SUV has it.)


2024 EQS SUV will have it. This information is confirmed based on order guides.

[ricerboi]

Originally Posted by bmwix1

Instead of 80 -> 30 -> 80, 50% dis/charging cycle,
Perform small dis/changing cycles between 25~35%
discharge: 80 -> 45
charge: 45 -> 70
discharge: 70 -> 35
charge: 35 -> 60
discharge: 60 -> 30
charge: 30 -> 65
discharge: 65 -> 35
charge: 35 -> 70
discharge: 70 -> 45
charge: 45 -> 75
discharge 75 -> 50
charge: 50 -> 80
repeat

It will prolong the battery.

Regen braking is basically fast charging battery at frequent but very small cycle and short session. It doesn't hurt the battery.

Ideal if you can only discharge that little per day. I'm discharging 50-70% daily and need to DCFC 60%-80% daily. Honestly, less than 5% of iX owners on this forum actually drive/charge enough for this to matter. Agreed that this type of charge/discharge behavior is better for optimal battery life, but I would hope that in practice, let's not scare off potential owners by making them overthink it.

I've DCFC'ed over 25,000kWh on EA DCFC the last 14 month's I've had the iX and the range is still fine. I'm not going to cry over 10% in lost max range in 8 years (if I still even have the car). I'm happy with 90-95% of max range during 5 years/150k miles of ownership.

[bmwix1]

I am just providing an alternative way to optimize battery charging/discharging cycle within 80~30 range.

For most owners the easiest way is just set +/- 25% around the center mark, 50% SoC. Set charge target to 75% and recharge when battery reaches 25% SoC.

Car is a commuting tool, so charge/discharge whatever way to fit owner's schedule and need.