how bad for the battery is supercharging?

[msnow]

One thing I've found is that if you ask 100 different Tesla personnel you'll get close to 100 answers.

Funny, just finished saying the same thing.

 

[Canuck]

That's right. If you don't want to overthink it, then do what Tesla says and it's *nearly* as good as you could get.

When they say 90% is fine it doesn't mean they think it's best. If 70% is fine for your daily needs, set the slider to that and leave it there.

If you're the type that just can't handle any planning at all and every now and then you need more than 70% and if you can't remember the night before that you'll need that, then just set it to 90% and leave it there....even if it isn't quite as good for the battery as leaving it at 70% but it probably won't make a difference of more than a few % degradation over the life the the car.

It's too bad the 12v battery can't be charged from shore power.

Right. The ideal for lithium ion batteries is to cycle around 50%. So you set the daily driving slider based on your daily driving to accomplish that -- i.e. charge to 70, get home at 30, recharge to 70 -- or 75, home at 25, recharge to 75 -- or 80 home at 20, recharge to 80, etc., etc. In these examples, you're cycling around 50% and that's the best. The research has proven that. But I didn't say that for the reason you point out about it not making that big of a difference over the life of the car provided you do the three important things I mentioned above.

 

[ThosEM]

What lessons are people taking away from Jeff Dahn's lecture (video up thread)? Here's mine:

The longer you spend charged to higher voltages (SOC), the faster degradation is. Or, the more time you spend at low voltages (SOC) the slower the degradation. So fill up when necessary; otherwise stay mid-range as a compromise between useful range and degradation.

The cooler you keep the battery, the better (store in a refrigerator). So the AC really cranks when supercharging on a hot day. And you shouldn't keep a hot ICE car in the same garage with your EV.

Note: I've been charging to 90% with few exceptions for 2.5 years, with essentially no degradation as judged from my 90% range calculation; 231 miles on day 1, and 232 miles the last time I checked...

 

[Ali’sMax]

It's not bad the battery to use the SC, but it is bad for the battery to charge and discharge over a large range of it's capacity repeatedly. i.e. it will last a lot longer if say keep it at 70% and if you're only using 10% day, great, charge at home at night back up to 70 and you're battery will last forever going between 60 and 70%. It will degrade faster going from 90 to 20% over a week and then charging that 70% back up at the supercharger.

Thank you sooo much for your explanation!
I’ve been doing it wrong all these time!
I usually charge it to 80% and let it drain down to 20% then charge it back to 80%
I do weekly long trip so I do charge weekly to 100% but I would still have 20% remaining when I get to my destination
So far 10,000miles and 3% degradation I’m worried about battery loosing it’s capacity too quickly

 

[AmpedRealtor]

According to this article and Tesloop's experience, a lot of supercharging is bad and will eventually lead to battery replacement. Also look at what Tesla told Tesloop in this article, as quoted. It contains some valuable tips.

Tales from a Tesla Model S that hit 400,000 miles in 3 years

 

[TexasEV]

Not really relevant to 99+ % of owners. The cars were superchargered several times per day, seven days a week, for years.

 

[David99]

According to this article and Tesloop's experience, a lot of supercharging is bad and will eventually lead to battery replacement. Also look at what Tesla told Tesloop in this article, as quoted. It contains some valuable tips.

Tales from a Tesla Model S that hit 400,000 miles in 3 years

The note/recommendations from Tesla are interesting. Of course almost no one drives that much and uses superchargers that much, but the info about giving the battery a rest after it's been driven to a low SoC is interesting.