[jkramerXXX7]

Absolutely love my 50e. So far I've almost emptied the battery every day on my daily commute. I generally plug in every day at work and again when I arrive home. I've read that frequent charging will degrade the battery and shorten its lifespan. I currently don't plan on changing my routine. I bought a PHEV to drive in electric mode as much as possible and that will require nightly charging. Any 45e owners or 50e owners have opinions on charging techniques? Do you always charge to 100%?

[eelnoraa]

45e owner here, I just use the car. I charge it when I can, and if usage needs t run down the battery to "---", so be it.

For 45e, I don't think we know if what the car says 100% is the 100% of the battery. The 30% buffer BMW keeps from us, we don't know where it is allocated. My best guess is 15% at bottom, 15% on top. So we are just using 15%-85% range. so when we charge to 100% according to the car, it is about 85% of the battery capacity. Pure guess here.

[nZtiZia]

ABC = always be charging

full charge cycles (0-100% of gross/net capacity) leads to a faster decrease in battery life. BMW addresses this by allowing only a portion of it be usable. each full charge of this usable capacity isn’t a ‘full’ charge cycle

[javapro]

Originally Posted by eelnoraa

45e owner here, I just use the car. I charge it when I can, and if usage needs t run down the battery to "---", so be it.

For 45e, I don't think we know if what the car says 100% is the 100% of the battery. The 30% buffer BMW keeps from us, we don't know where it is allocated. My best guess is 15% at bottom, 15% on top. So we are just using 15%-85% range. so when we charge to 100% according to the car, it is about 85% of the battery capacity. Pure guess here.

It's not really top or bottom. The car simply charges each and every cell in the battery to a certain percentage but never to 100%, thus, as correctly pointed out by nZtiZia, decreasing the number of full charge cycles (0 to 100%) which prolongs battery life.

[RetSurfer]

I've read on here several times to set the charge to 80%. So what you're saying is that is incorrect, the battery already has that worked in?

[javapro]

Originally Posted by RetSurfer

I've read on here several times to set the charge to 80%. So what you're saying is that is incorrect, the battery already has that worked in?

Yes!

[nZtiZia]

Originally Posted by RetSurfer

I've read on here several times to set the charge to 80%. So what you're saying is that is incorrect, the battery already has that worked in?

did you read counter arguments to said advice that followed? (i'm sure i chimed in! ) it is generally sound charging advice to charge lithium batteries to 80% whether they be in a phone, wireless headphones, full electric vehicles (BEV/EV), etc that utilize their battery's full capacity.

current BMW plug-in hybrid vehicles (PHEV) do not utilize its battery's full capacity. it is portioned into a smaller usable capacity. as such, the advice you read doesn't apply. read my previous post about full charge cycles.

[mopaman]

Originally Posted by jkramerXXX7

Absolutely love my 50e. So far I've almost emptied the battery every day on my daily commute. I generally plug in every day at work and again when I arrive home. I've read that frequent charging will degrade the battery and shorten its lifespan. I currently don't plan on changing my routine. I bought a PHEV to drive in electric mode as much as possible and that will require nightly charging. Any 45e owners or 50e owners have opinions on charging techniques? Do you always charge to 100%?

With the range you have with most plug in hybrids, you have to charge every day (or at least as often as you drive) to get the full benefits of the pure electric or electric assisted driving.

[RetSurfer]

Originally Posted by nZtiZia

did you read counter arguments to said advice that followed? (i'm sure i chimed in! ) it is generally sound charging advice when charging lithium batteries whether they be in a phone, wireless headphones, full electric vehicles (BEV/EV), etc that utilize their battery's full capacity.

current BMW plug-in hybrid vehicles (PHEV) do not utilize its battery's full capacity. it is portioned into a smaller usable capacity. as such, the advice you read doesn't apply. read my previous post about full charge cycles.

Got it, thank you...

[aquanox]

My 45e is about 1 year old and charged daily. Current Energy content of the high-voltage battery is 15.2kWh, so about 11% degradation.

Also, when fully charged, the 45e pack voltage is 399.5v, average cell voltage 4.16V. Meaning the 30% reserved is all at bottom, which I believe is not ideal for longevity.

I live in texas btw, hot summer.

[eelnoraa]

Originally Posted by aquanox

My 45e is about 1 year old and charged daily. Current Energy content of the high-voltage battery is 15.2kWh, so about 11% degradation.

Also, when fully charged, the 45e pack voltage is 399.5v, average cell voltage 4.16V. Meaning the 30% reserved is all at bottom, which I believe is not ideal for longevity.

I live in texas btw, hot summer.

Very good founding. I totally agree, getting this high isn't great for the cell.

[eelnoraa]

Originally Posted by javapro

It's not really top or bottom. The car simply charges each and every cell in the battery to a certain percentage but never to 100%, thus, as correctly pointed out by nZtiZia, decreasing the number of full charge cycles (0 to 100%) which prolongs battery life.

I kind of agree here on first order consideration. But I think 10% cycle of the battery create different stress if it is 50-60% vs 90-100%. Toward the extreme end, the stress is much higher. That is why Tesla recommend 20-80% SoC, not 40-100%, not 0-60% For 45e, it makes the most sense to have 15-85%. 30-100% will stress more.

[LogicalApex]

I wouldn't worry about managing battery longevity on any modern device, including BMW PHEVs. Battery technology has improved dramatically, but also so has the complex charger logic used to charge these batteries. The charger isn't as simple as "charge battery to full" like they were for older battery chemistries. There is a complex algorithm at play to balance everything from cell temperature to charge states in an effort to extend battery pack life and minimize degradation. The primary source for degradation is actually heat. Batteries wear out faster as they heat up more. BMW manages heat via actively cooling the battery pack.

If you tried to manage the charge state of the PHEV you're in for a lot of extra work that I think is wasted energy...

As nZtiZia stated... ABC (Always Be Charging).

[jad03060]

Not every manufacturer manages battery health well. It may have changed, but the last time I looked at say a Nissan Leaf...you were warned not to do too many DC fast charges on a road trip, as you'd damage the batteries. They don't (didn't?) put the money and research into managing the battery health, and had lots of problems with people that lived in say the US desert SW as a result. I've not heard of that sort of issue with BMWs.

[Chonkapotamus]

Originally Posted by RetSurfer

I've read on here several times to set the charge to 80%. So what you're saying is that is incorrect, the battery already has that worked in?

In practice, how does one even set the charge to 80%? Doesn't the battery hold setting specify a charge floor, below which it won't fall in hold mode, not a charge ceiling? When I took delivery the "genius" told me to sey that to 80%, but it didn't seem to keep the car from charging up to 100% (which I know is 80% of EU spec).

[nZtiZia]

Originally Posted by Chonkapotamus

In practice, how does one even set the charge to 80%? Doesn't the battery hold setting specify a charge floor, below which it won't fall in hold mode, not a charge ceiling? When I took delivery the "genius" told me to sey that to 80%, but it didn't seem to keep the car from charging up to 100% (which I know is 80% of EU spec).

the following post shows where to set the charge level
https://www.bimmerpost.com/forums/sh...php?p=30091772

the 50e BATTERY HOLD simply holds whatever the charge level is at the time the hold is activated. at least that’s what I understand from other posts

[Chonkapotamus]

Originally Posted by nZtiZia

the following post shows where to set the charge level
https://www.bimmerpost.com/forums/sh...php?p=30091772

the 50e BATTERY HOLD simply holds whatever the charge level is at the time the hold is activated. at least that’s what I understand from other posts

Thanks. Is there a comparable option in the 45e? Our menus are different.

[nZtiZia]

Originally Posted by Chonkapotamus

Thanks. Is there a comparable option in the 45e? Our menus are different.

the 45e has BATTERY CONTROL which is different than the 50e BATTERY HOLD. with BATTERY CONTROL, you can set the charge level between 30-100%. note this setting only addresses charging the battery while driving. once the level is reached, the vehicle will hold that charge.

the 45e doesn’t have a way to adjust the charge level when stationary and plugged in like the 50e can, if that’s what you’re asking about. when plugged in to charge, the vehicle always fully charges the battery. one may be able to limit the charge level only if the EVSE supports it (my JuiceBox can)

[Chonkapotamus]

Originally Posted by nZtiZia

the 45e has BATTERY CONTROL which is different than the 50e BATTERY HOLD. with BATTERY CONTROL, you can set the charge level between 30-100%. note this setting only addresses charging the battery while driving. once the level is reached, the vehicle will hold that charge.

the 45e doesn’t have a way to adjust the charge level when stationary and plugged in like the 50e can, if that’s what you’re asking about. one may be able to do this only if the EVSE supports it (my JuiceBox can), but to reiterate, there’s no setting in iDrive to do so. when plugged in to charge, the vehicle always fully charges the battery.

Thanks, that's what I thought. So the 80% charge debate for a 45e is largely academic. There's no way with the BMW supplied charger in the US to only charge to 80% (of EU 80%), unless you are going to babysit your charging session and unplug your car.

[SwissBeemer]

Originally Posted by mopaman

With the range you have with most plug in hybrids, you have to charge every day (or at least as often as you drive) to get the full benefits of the pure electric or electric assisted driving.

There was an extensive debate over here as to why the last part of your statement (electric assisted driving) is not true.

[mopaman]

Originally Posted by SwissBeemer

There was an extensive debate over here as to why the last part of your statement (electric assisted driving) is not true.

I would stand by my statement that you would need to charge to get the full benefit of e assist. Most of the time it is available, but under a very high load, or starting out on a very cold day with an “empty” battery it is limited.

[jad03060]

FWIW, on a very cold day where the battery is cold soaked, REGARDLESS of the battery charge level, you may not get any assist until things warm up some. Since so many of the things run off of 12vdc, and those batteries aren't huge, the HVB will be supplying some power through either the EV motor as an alternator, or directly from the HVB, but regardless, some power will be moving through those systems, which will warm them a bit.

10 charges from 90-100% is the same wear as one from 0-100%. If you manage the heat during charging, that helps, as does when it slows the charge as it approaches full. So, a partial charge, partly because of the time involved, the power input, and the slowing is less wear than a full charge from an indicated zero.