Superchargers shorten life of battery?

[David_Cary]

Huh?
If 80A is harder on the battery, what does Supercharging do to it?

It is harder on the battery than 80A.

All of this is not rocket science. Charging creates heat, heat speeds up chemical reactions including degradation.

Yes, some have supercharged 500 times and have normal range degradation. But all things being equal, a battery will live longest at coldest temperature (above 40 or so). 80A charging will heat the battery more than 40A charging. Will it make a practical difference in the car's lifetime? - probably not.

Generally, if I only need 40 miles a night, it is just safer in multiple ways to charge at 40A (or even 30A). At some point, there is usually an efficiency hit at too low of an amperage so I would not really go lower.

 

[kmcdds]

Heat degrades batteries. Extremly High State of Charge degrades batteries (as does extremely low state of Charge). Charge cycles degrade batteries. Time degrades batteries.

You can't avoid time unless you live in a different universe than I do. You pretty much can't avoid charge cycles if you plan to drive the car so that leaves heat and state of charge.

Turns out heat and state of charge interact very much. High heat at low state of charge causes less damage than high heat at high state of charge (by a lot).

You can only control heat if you keep your car stowed away in an air conditioned garage. So if you park your car outside and drive it on the road (as I do) your last and only controllable factor out of all 4 we started with is ... you guessed it State of Charge.

I can't control how hot my parking lot at work is or how hot the highway is. I can park under a tree and move the car between morning shade and afternoon shade but that doesn't change much.

I can charge my car less when it will be hot out. That is my only major control on how my cars battery pack ages. Everything else is minor.

OK I could move to Canada or Norway or somewhere else near the arctic circle but given my current home zip code all I can really do is control State of Charge.

Now Tesla does have a cooling loop for the main pack and that makes it much less of an issue. But extra heat at high state of charge is such an issue you'll spend more energy cooling the pack if SOC% is high so a higher SOC% in hot weather equals less range and higher cost per mile driven. Also note Tesla is likely choosing to optimize temperature for performance more than longevity. You can tilt that back a little towards balanced if you change your max SOC% based on outside temp.

It's no absolute deal breaker, you can ignore it if you want. I'm just used to thinking this way coming from a cheaper EV that has no cooling for the main pack. Just like I check my tire pressure and adjust when the temperature increases or decreases, I do similar for my battery pack by adjusting my max SOC% when the temperature increases or decreases.

Thanks for explaining that in detail. I really appreciate it.

 

[hacer]

I SHOULD be able to do 80A whenever I feel like it and not be concerned about it heating up so much.

You can! It gets hot, but not enough to be concerned about. So don't be concerned unless you see smoke or flames or burn yourself on the handle.

 

[jerry33]

The Model S and X and 3 all recommend charging to only 90% which is also the default setting.

And bear in mind that before the EPA changed the rules, there were only three settings 50% for storage, 93% for daily use, and 100% for trips.

 

[Glamisduner]

It is harder on the battery than 80A.

All of this is not rocket science. Charging creates heat, heat speeds up chemical reactions including degradation.

Yes, some have supercharged 500 times and have normal range degradation. But all things being equal, a battery will live longest at coldest temperature (above 40 or so). 80A charging will heat the battery more than 40A charging. Will it make a practical difference in the car's lifetime? - probably not.

Generally, if I only need 40 miles a night, it is just safer in multiple ways to charge at 40A (or even 30A). At some point, there is usually an efficiency hit at too low of an amperage so I would not really go lower.

I was planning on charging off a Laundry 240v (NEMA 14-30) outlet until I can fork up the cash to have a new outlet run (Box is on the opposite side of the house and the attic run will not be easy due to the roof being so low).

Is this a bad plan?

 

[jerry33]

I was planning on charging off a Laundry 240v (NEMA 14-30) outlet until I can fork up the cash to have a new outlet run (Box is on the opposite side of the house and the attic run will not be easy due to the roof being so low).

Is this a bad plan?

Depends on how many miles you drive in a day. A 14-30 charges at 24 amps as opposed to 40 from a 14-50. Still far better than charging at 120V.

 

[Dan_LA]

Doesn't really matter much if you charge it every day or every 2 days or every 3 days as long as you don't have an unexpected need for a longer trip. So I plug it in every night just for the what if factor.

I'd charge higher if it's below freezing out and lower if it is hot enough to use air conditioning for any reason.

So think like this if range isn't an issue:

100% for unusual circumstances (like right before a trip, but very shortly before)
90% in the winter
80% spring and fall
70% summer
60% if its the hottest day of the summer and you can handle the range limitation
50% if you are going to leave it sitting for a day or two, charge it back up if needed later before you use it.

If you are lazy or don't want to hassle pick a number from the above that fits an average and lit it use that most of the time.

But me I change my charging behavior based on use and temperature.

Best Tips over this Thread.

I tend to keep 90%, since I just took delivery last week, I was going to test battery down to 20% to see if there is any problems down low. Is that a requirement to check? Before going down 20% in a road trip?

Anyway, will keep at 90% and charge once I remember every 3-4 days (my daily commute is 45miles). Nothing compared to my i3 70 miles range, Rex relieves a little bit, but definitely limited me few times in 3 years.

I'm pretty sure tons of people have abused Supercharger as being Unlimited, it's a no brainer to use and abuse the car. So either way I think we should be safe with battery, will see, we have more 5 years to check on an old Model S with 500k miles.