Continual supercharging and battery life

[gnuarm]

Certainly it's good for any merchants to support charging. I think ultimately it will be imperative that charging become universal. That doesn't mean Superchargers are required. In the current cars I don't know how good for the battery it is to continually fast charge. I guess that's what has been discussed here and I think the consensus is that this was a problem for a specific version of the Tesla batteries, but not universal. An easy way to completely avoid the problem is to slow charge at level 2 chargers virtually any time the car is stopped. So if merchants provide that sort of facility it will make life a lot easier for BEV owners.

I'm puzzled as to why larger companies aren't on board with this. Some motel chains are happy to provide an appropriately minimal charging capability. I'm seeing charging at hospitals. Some government connected facilities seem to support it. Otherwise it is still hit and miss. That's not a good way to encourage BEV sales.

 

[gnuarm]

When using the Superchargers the charging rate can be limited to something lower.

I checked and when using Superchargers I don't have the ability to throttle them back. This is only an option with AC charging.

 

[tga]

Lots of discussion of rate-limited 90kWh packs here - If you fast charge, Tesla will permanently throttle charging

The MPH ranged from 100, 150 and 200 when typical at Superchargers is 300+.

You shouldn't focus on MPH. That is an average over the entire charging session, and hard to get apples-to-apples comparisons. kW is current instantaneous charge rate.

 

[gnuarm]

Lots of discussion of rate-limited 90kWh packs here - If you fast charge, Tesla will permanently throttle charging


You shouldn't focus on MPH. That is an average over the entire charging session, and hard to get apples-to-apples comparisons. kW is current instantaneous charge rate.

Not sure what you mean about "average". The display indicates a kW number as well as a MPH number. They are related by a simple multiplier. No averaging involved really. Perhaps you are thinking of the added miles number?

 

[David99]

Not sure what you mean about "average". The display indicates a kW number as well as a MPH number. They are related by a simple multiplier. No averaging involved really. Perhaps you are thinking of the added miles number?

When Supercharging the MPH number is an average over the entire charge session. A Supercharger typically starts with higher power and then reduced the power as the battery fills up. The MPH number is the average over the entire time. The power shown in kW is the current power. In a Model X you can take that number and multiply it by three to get the current charge rate in MPH. For example if you are charging at 30 kW, you are charging currently at aprox 30 x 3 = 90 MPH.

 

[gnuarm]

When Supercharging the MPH number is an average over the entire charge session. A Supercharger typically starts with higher power and then reduced the power as the battery fills up. The MPH number is the average over the entire time. The power shown in kW is the current power. In a Model X you can take that number and multiply it by three to get the current charge rate in MPH. For example if you are charging at 30 kW, you are charging currently at aprox 30 x 3 = 90 MPH.

I stand corrected. That explains some of the odd numbers I've seen.

Any idea what the purpose of that is??? I really don't get some of the very odd things they do regarding reporting data. Another one is the difference in the energy displays. The one on the main console shows short term averaged graph for WHr/mi with lines showing a long term average and I suppose the EPA rating number. The energy display on the driver console shows the graph, but not the lines but also shows a non-averaged thermometer for power, but no readout.

I get there is a lot of data to show and they don't want to crowd the display, but the graphs and thermometer aren't so useful if you can't actually know the values at any given point, at least to me.

 

[David99]

I stand corrected. That explains some of the odd numbers I've seen.

Any idea what the purpose of that is??? I really don't get some of the very odd things they do regarding reporting data. Another one is the difference in the energy displays. The one on the main console shows short term averaged graph for WHr/mi with lines showing a long term average and I suppose the EPA rating number. The energy display on the driver console shows the graph, but not the lines but also shows a non-averaged thermometer for power, but no readout.

That explains the different ways the cars shows energy consumption and how to use it. (I hope you like cats)

 

[Carleen Cullen]

I have this same predicament except the Supercharger is the only charging resource I have. Fingers crossed nobody is hiding the info behind the scenes!

Could you update me on how the battery is doing with only supercharging? Also, how many miles do you drive? Thanks

 

[TaoJones]

Could you update me on how the battery is doing with only supercharging? Also, how many miles do you drive? Thanks

1st Model S (late 2014 S85): ~64K miles, 98% SCing, 3.7% degradation.

2nd Model S (early 2017 S90D): ~46K miles, 99% SCing, 6.8% degradation and holding steady for the last 20K miles or so.

In both cases, they said to expect 10% degradation at 100K miles. I know people with Teslas @ >100K miles and not one of them has gotten to 10% yet.

 

[gnuarm]

1st Model S (late 2014 S85): ~64K miles, 98% SCing, 3.7% degradation.

2nd Model S (early 2017 S90D): ~46K miles, 99% SCing, 6.8% degradation and holding steady for the last 20K miles or so.

In both cases, they said to expect 10% degradation at 100K miles. I know people with Teslas @ >100K miles and not one of them has gotten to 10% yet.

Musk put up some graphs in a Tweet once that clearly showed much better battery life than expected. At first I thought the graph was horrible plotting capacity drops down to 50%. But when I looked at the X axis I realized they were talking about the equivalent of 400,000 miles and more. I wish I had a link to that graph. I'd like to look at it again.

I think in the first 200,000 miles most use cases didn't even loose 10%. Musk was making the point that their earlier warning to not charge all the way to 100% on a regular basis was a bit overly cautious. Seems even if you charge to 100% every time it might only cost you an extra 5% at some point. It really wasn't much of an impact.

Compare that to the Leaf which seems to have 30% degradation of capacity in 100,000 miles. Hopefully they will address this issue.

 

[selfbp]

Could you update me on how the battery is doing with only supercharging? Also, how many miles do you drive? Thanks

I actually noticed 0% change in my max charge. My S75 rwd still gets 232miles at 100% and I’ve logged a total of 30,xxxmi in almost 2 years.

Probably about half being supercharged miles. I’m going to go ahead and say with full confidence that long term supercharging isn’t noticeably effecting anything worth worrying about.
Probably the equivalent internal effects of running 87 octane vs 89 octane gas in an ICE car; might not be ideal but it’s still going to work fine long term

 

[David99]

I actually noticed 0% change in my max charge. My S75 rwd still gets 232miles at 100% and I’ve logged a total of 30,xxxmi in almost 2 years.

Probably about half being supercharged miles. I’m going to go ahead and say with full confidence that long term supercharging isn’t noticeably effecting anything worth worrying about.
Probably the equivalent internal effects of running 87 octane vs 89 octane gas in an ICE car; might not be ideal but it’s still going to work fine long term

I'm pretty convinced that Tesla is masking the initial capacity loss these days. I've been reading here for almost 6 years now. A large amount of discussions is people worried about losing range right after they got their cars. Battery degradation is one of the big unknowns and fear regarding EVs, so naturally many people keep a close eye on that when they get an EV.

It is perfectly normal for a battery to lose a small amount of capacity in the first few weeks and months (depending on how much you drive). That initial drop doesn't last long and then degradation happens at a slow and steady pace with use and age. To save themselves from thousands of concerned new owners calling to report a range loss they have seen in their new car, Tesla is just masking it by starting with a lower than actual range. Saves them a huge amount of unnecessary trouble and concerns and calls.

 

[Nguyenning]

I got 10K free supercharging miles from referrals and live 2 miles from a supercharger... My plan is to solely rely on supercharging until these bonus miles go away. I'll never plug in at home because, well, free is free.

So... I hope it doesn't harm the car!

 

[M3P Driver]

I’ve got about 16k miles on my M3P, half or more from supercharging. I got the car in September of 2018z I’m noticing a 90% SOC equals 262 miles of estimated range, down from 279 when new and 100% SOC is showing 293 miles. Seems a bit low?

 

[ajdelange]

I got 10K free supercharging miles from referrals and live 2 miles from a supercharger... My plan is to solely rely on supercharging until these bonus miles go away. I'll never plug in at home because, well, free is free.

So your time is worth nothing?

So... I hope it doesn't harm the car!

It won't if you crank the rate down to, I'll guess, less than 20 kW.

 

[tga]

It won't if you crank the rate down to, I'll guess, less than 20 kW.

Which you can't do. Supercharging is under control of the BMS, and runs at the maximum rate for the current conditions (battery temp, state of charge, etc). You can't slow it down.