Which is better? SC 40 - 80% or L2 20 - 90%?

[afeudale]

After a *lot* of trying, we never ended up getting charging installed at our condo building for our 2020 M3 SR+

What we've mostly been doing for the past year we've had the car, is to L2 charge (ChargePoint, Flo, etc) whenever at a destination (such as a coffee shop, etc). We would charge as much as possible, up to 90% max, usually hover around 30-50% throughout a given week (with 2-3 hour L2 charges during the week) and often get down to 20%.

Recently, have been reading that supercharging isn't as bad for the battery as we originally thought and that keeping the battery at a decent charge level (40 - 70%) was better for it.

Curious what the community thinks is the better approach - SC to a max of 80% and try to never go below 40% *or* continue to do the L2 charging when needed, but sometimes getting down to 20% SoC.

 

[GtiMart]

I believe L2 charging is gentler on the battery and that 20% is really not low enough to cause any harm. If that works for your lifestyle then go for it. If supercharging fits your life better, it won't ruin the car. Especially if you're starting at 40% it won't charge that fast.

 

[Xebec]

Went for L2 because of the high battery temps on the SC especially above 70% charge.

 

[jjrandorin]

One thing we know from how battery science works (there are several excellent posts here on TMC with information on this), is that "fast charging" is "less healthy" than slower charging. For a tesla model 3, most define "fast charging" as DC charging that passes the onboard charger.

What we dont know is "how much" healthier it is over the long term. We know that on model S vehicles, when they supercharge all the time, tesla throttles the supercharging speed on those vehicles. No one on model 3 has experienced that... yet.

So, with all that as a backdrop, I would say its better to supercharge "less" but I also would not stress about it that much. Do whichever one is more convenient for you. if I HAVE to make a choice, if it were me, I would charge level 2 more, and supercharge a bit less, unless the level 2 charging was inconvenient. I absolutely would not go to a store that had a level 2 charger just to charge, for example.

 

[afeudale]

Thanks for the replies everyone!

Yes, was pretty confident that slower charging was better than faster, but the "wrench" thrown into that is that when we L2 charge, we typically don't get around to it until 20% (or lower...even as low as 5% sometimes...).

If supercharging, we could keep it at a higher charge level as there are a lot of SC stations around the city.

Was reading that Li batteries typically like to stay in "the middle" of their SoC, say, 40 - 70% range. That is why I thought maybe SC might be better.

I'm probably overthinking it all

 

[GtiMart]

You are overthinking it, like many people on the forums
20%, or even lower, is perfectly fine. Maybe 0-5% is a bit hard. Supercharging doesn't kill batteries, you'll find plenty of people that SC a lot. It's fine to follow some rules of thumb, as long as it doesn't prevent you from using and appreciating your car. There is plenty of technology in the car to keep the battery healthy.

 

[jrweiss98020]

Curious what the community thinks is the better approach - SC to a max of 80% and try to never go below 40% *or* continue to do the L2 charging when needed, but sometimes getting down to 20% SoC.

Either or both, whichever is most convenient.

 

[afeudale]

Thanks everyone for the replies! Will try to be a bit more relaxed about it

It's just a pain sometimes not having charging at home and something urgent comes up, although we've managed pretty well for almost a year now!

And in that time only twice took it down to 0% (which is pretty nerve-racking btw)....one time, -20C, snow everywhere, car estimated -3% to make it to the nearest SC, and we practically rolled into the station...lol

 

[nwdiver]

After a *lot* of trying, we never ended up getting charging installed at our condo building for our 2020 M3 SR+

What was the hitch?

 

[Gasaraki]

According to some people on this forum even 11Kw charging at home is bad for your battery. I had an argument with someone in another post about that. People think Teslas are some fragile little princess that that needs to be babied or else the battery will just die.

 

[ucmndd]

According to some people on this forum even 11Kw charging at home is bad for your battery. I had an argument with someone in another post about that.

What you actually did was come in and crap all over the place without making any effort to understand what people were saying nor the information being presented.

 

[Candleflame]

According to some people on this forum even 11Kw charging at home is bad for your battery. I had an argument with someone in another post about that. People think Teslas are some fragile little princess that that needs to be babied or else the battery will just die.

it is better but you will get questionable returns.... Tesla batteries already cycle quite shallow.
The battery reserves 4.23% (of 94%) on the bottom as a buffer and probably has another 1-2% as brick protection. 100% (4.15V) is actually only 94%. So even cycling displayed 0 - 90% only cycles around 79-80% of the battery. 11kw (0.1c) charging already doesnt put too much stress on the battery so it probably doesnt matter at all given the shallowish cycles.