Audi e-tron Forum – News, Specs, Pricing & Ownership… banner

1 - 9 of 9 Posts

·
Registered
Joined
·
10 Posts
Discussion Starter #1
On a separate note, has anybody set their car to charge to a target limit (say 80%) and have the car charge past target limit?

Thanks!
 

·
Registered
Joined
·
23 Posts
To set some context, my spouse and I both work remotely. Even before Covid-19 began. So, commuting is not a part of our daily routine.

From what I had learned from a computer manufacturer about lithium ion, it's best to keep lithium ion charged at a "neutral" state of total capacity for battery health (~50% to ~70%). Therefore, we'd decided set our limit at 80% and refrain from plugging in unless the percentage drops below 50%. Unless of course we would need maximum miles for range, decide to go off-offroading, drive in Sport mode with the AC/heater on max, charge computer(s), etc. Also, lithium ion fares better in this "neutral" state when the element is not in use for long periods of time (storage, vacation, quarantine, etc.).

On the flip side, lithium ion likes to be in constant motion/consumption. So if a long 2-4 hour round-trip commute were a part of our daily routine, 100% charge it is. Just as long as we use it. When we bought the car, I recall being advised by the Audi e-tron team at the dealership not to let the battery sit fully charged (100%) or drained (<20%) for days on end. So IMO, the theory around lithium ion battery health/maintenance makes sense.

A little extra:
A close family friend is a programer and writes mobile apps for a living. Many years back, he was contracted with one of the major EV charging networks (pre Electrify America) to help script their mobile app. During that tenure, he learned that constantly charing an EV using a "supercharger" or High Power Charger (HPC) as the only means of charging puts undue stress on the battery. Not sure how this holds up in today's world, but perhaps someone with more science may chime in.
 

·
Registered
Joined
·
10 Posts
Discussion Starter #3
Sorry. I was just asking about if you set you r car to charge to 80% and it doesn’t stop until 84-85%... if that’s happened to some. Not sure what it doesn’t stop at the 80% like it’s programmed to do.
 

·
Premium Member
Joined
·
221 Posts
If I set the charge limit in the vehicle itself, it doesn't seem to go past 1% or so of the value set. I suspect there is a margin of error.

Also don't forget that Audi limits the usable capacity of the 95kW battery to 83kW or so. So an indicated "100%" state of charge (SOC) is more like ~88% actual charge. I factor that in to my charging practices, depending on how frequent or far I need to drive.

I too work from home and with a 40amp charger in the garage, its really not a big deal keeping it lower. Plenty of range for 99% of my driving with zero concern.
 

·
Registered
Joined
·
10 Posts
Discussion Starter #5
Okay thanks wasn’t sure how “normal” this was. I set to 80% on the app and it charged through to 82%, but app initially alerted me when it hit the 80%.
78D25A03-A1B8-489C-A3B7-3EF3C48B886D.png
 

·
Registered
Joined
·
10 Posts
Discussion Starter #6
May be something correlated to the charging issues I’m having. Audi is looking at the charger to try and diagnose
 

·
Registered
Joined
·
50 Posts
If I set the charge limit in the vehicle itself, it doesn't seem to go past 1% or so of the value set. I suspect there is a margin of error.

Also don't forget that Audi limits the usable capacity of the 95kW battery to 83kW or so. So an indicated "100%" state of charge (SOC) is more like ~88% actual charge. I factor that in to my charging practices, depending on how frequent or far I need to drive.

I too work from home and with a 40amp charger in the garage, its really not a big deal keeping it lower. Plenty of range for 99% of my driving with zero concern.
Indeed they limit the battery charge itself so you never reach 95kw
 

·
Registered
Joined
·
23 Posts
Sorry. I was just asking about if you set you r car to charge to 80% and it doesn’t stop until 84-85%... if that’s happened to some. Not sure what it doesn’t stop at the 80% like it’s programmed to do.
AH. LOL. I misunderstood the discussion. Apologies.
Yes. We've noticed that it goes beyond the 80% limit by 2% to 4% over. Not exactly sure why, but my best guess is that is has to do with the way the the cells distribute the energy? It's not like the software is calculating for one block of lithium ion. If you find out why officially, we'd love to know. And I'll chime back in if I find out as well.
 

·
Registered
Joined
·
162 Posts
To be honest, I had ALWAYS seen it go to 80% as it is set to (one time in the past year it stopped at 79%).
This morning it was at 82%

669
 
1 - 9 of 9 Posts
Top