I charge to 75% at just 5.7kw, and I don't even notice the difference

[j.w.s]

To preserve battery life, Porsche recommends charging to a maximum of 85% for daily use, using 100% charges only for longer trips. This is a Lithium battery thing, not a Porsche thing, often discussed on the forum. I know quite a bit about batteries, so preserving battery capacity over time is something I think about.

Other discussions talk about 22kw, 11kw, and 9.6kw charging, and of course fast charging up to 270KW. Faster is better, right? Except that faster charging is slighly more harmful to the battery, at least after many hundreds to housands of cycles.

Here is my observation after a few months of ownership:

I recently changed my day-to-day charge level from 85% to 75%, and I changed my EVSE maximum charge rate from 48A to 24A via its software. Doing so very likely extended the lifetime of my battery pack by up to a few years, and yet I do not notice any inconvenience at all, and here is why:

My typical Taycan drive is <100 miles, for which a 75% charge level is more than enough. Right now, at 75% charge, my GTS on 21" wheels says it can drive 178 miles. If I do plan a longer trip, I'll know the night before, and I will use my phone to activate a trip timer with a higher charge percentage. Even a last-minute longer trip typically gives me an hour or more to top-up if necessary, bringing the charge level up while I go about my morning business.

When I get home from a day of driving, having used say 40khw, an overnight charge at the slow 5.7kw charge rate is more than enough to top back up to 75%, gently.

So even though I software-neutered my battery capacity and my charge rate both, the car is no less convenient to use, ever. 90% of the time I just drive, longer trips take just a timer, and worst case, I might someday spend 30 seconds changing the EVSE charge rate and the Taycan charge timer and I'm back to 11kw charging and any charge percentage I need.

I'll say it again: If you are like me, you may be able to charge a bit more slowly and leave the battery a bit less full, without even noticing, while improving your battery health over the years, just in case you plan to keep the car for a very very long time like i do, or in case future used EV sales norms include stating the battery state of health - which they should.

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[simcity]

Honesty in the real world its actually doesn't make as big a difference to battery degradation as you may think.

Most of the degradation happens in the first year and several thousand miles of driving. Then unless there is something catastrophically wrong, it tends to level right out.

I wouldn’t get too hung up about it. Its a lot of angst for perhaps a percentage or two off degradation after many years.

 

[j.w.s]

Honesty in the real world its actually doesn't make as big a difference to battery degradation as you may think.

Most of the degradation happens in the first year and several thousand miles of driving. Then unless there is something catastrophically wrong, it tends to level right out.

I wouldn’t get too hung up about it. Its a lot of angst for perhaps a percentage or two off degradation after many years.

Since the change causes me absolutely no inconvenience, I don't need much if any improvement in future SOH to justify it.

But if you look at the data, I might see as little as half the battery degradation over the next ten years by being "a bit gentle" with the battery most of the time, a combination of gentle charging, judicious use of fast charging, and avoiding very high and very low SOC when possible. For example my SOH might in the far future be 92% instead of 85% - something that either is or isn't worth bothering with depending on your point of view. It's worth it to me though. There is some good data about battery degradation on the Internet, including here on the forum:

https://www.taycanforum.com/forum/threads/baseline-for-hv-battery-soh-performance.12815/

 

[ciaranob]

The difference in using a 60A hardwire hookup delivering 11kW but ca 10.5 kW at the car and say 9.6kW and high 8 kW at the car and even down to 7.5 kW will make very little if any impact on the longevity or more accurately the SoH of the HV battery.
However what will impact it is a use case where a person dominantly or solely charged with DC fast chargers and especially so in hot climates e.g. south of L35N.
I posted a study result on this from a large population of EV cars in the thread on Baseline SoH performance you could have a look at - typing on phone and I’ll copy the link in here later but easily found on the forum.

 

[ciaranob]

The difference in using a 60A hardwire hookup delivering 11kW but ca 10.5 kW at the car and say 9.6kW and high 8 kW at the car and even down to 7.5 kW will make very little if any impact on the longevity or more accurately the SoH of the HV battery.
However what will impact it is a use car where a person dominantly or solely charged with DC fast chargers and especially so in hot climates e.g. south of L35N.
I posted a study result on this from a large population of EV cars in the thread on Baseline SoH performance you could have a look at - typing on phone and I’ll copy the link in here later but easily found on the forum.

Ah just saw you linked to my thread

 

[ciaranob]

Since the change causes me absolutely no inconvenience, I don't need much if any improvement in future SOH to justify it.

But if you look at the data, I might see as little as half the battery degradation over the next ten years by being "a bit gentle" with the battery most of the time, a combination of gentle charging, judicious use of fast charging, and avoiding very high and very low SOC when possible. For example my SOH might in the far future be 92% instead of 85% - something that either is or isn't worth bothering with depending on your point of view. It's worth it to me though. There is some good data about battery degradation on the Internet, including here on the forum:

https://www.taycanforum.com/forum/threads/baseline-for-hv-battery-soh-performance.12815/

See posts above - but forget to add that you point is entirely valid in respect you are still doing more good than bad by using a lower charging rate overnight - its just incremental between the AC rates vs the impact of DC!

 

[Andy0565]

When I plug in my car at home my battery is charged to 60%. Then I pop a timer into the app for the next time I plan to use the car again and it’s charged to between 75% and 85% depending on my needs (normally 75%)

That way the battery spends most of its life at 60%.

it certainly doesn’t present any inconvenience. My home charger rate is 7.5kw.

I’ve not needed to charge to 100% as yet but, if that time comes, I doubt I’ll have any problems from a time perspective.

The Porsche approach to charging profiles along with timers is a step up in convenience compare to my Jaguar iPace which I ran happily for three years.

 

[Tsingtao]

I typically charge at 80%, but after reading your post intend to knock it down to 75%. I only drive 20-60 miles a day so what is the difference? And if I can preserve even a little more battery life for the next guy/girl who owns my Taycan (after I trade it in for a 718 EV) that may result in a little less lithium that will eventually need to be mined. Nothing better than driving a badass Porsche while simultaneously taking it easy on the environment!

 

[Jhenson29]

Doing so very likely extended the lifetime of my battery pack by up to a few years

That seems like a bold claim, and also very little context. How exactly are you arriving there? And, a few years…relative to what (I.e. how many years without the change?)

There is some good data about battery degradation on the Internet, including here on the forum:

I didn’t see anything in that post that supports your claim that reducing your current from 48A (actually 45.8A for 11kW @240VAC) to 24A helps the battery.

I mainly read the first post, not all 10 pages.

But if anything, that post you link shows that L1 is worse than L2, which suggests there’s an inflection point where lower power is worse. How do you know where 11kW and 5.7kW fall exactly and that there is any actual difference (or the difference isn’t worse) on the Taycan?

Even a last-minute longer trip typically gives me an hour or more to top-up if necessary

How do you “top up” from 75% at 5.7kW in an hour?

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