Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
Register

Does supercharging harm the battery?

This site may earn commission on affiliate links.
It only charges at full rate for the bottom half of the battery. At 50% the rate is reduced by half and I believe it goes down even more as it approaches full. There shouldn't be any more deterioration than with a home charge.

What's bad for the battery is charging to 100% (range charge) and then leaving it sit at 100%.
 
It isn't that high-amperage is bad, it is just that a Roadster owner verified charging at 30-40 amps was optimal for that car.

Could charge at higher amps, but lose electricity to overhead like cooling. I don't think anybody has measured it and shared the results for the Model S yet.
 
Hi all,

I'm trying to figure out whether or not I need the supercharger? I know that any high-amperage charge is bad for the battery, but how much does it actually effect the pack?
The specific cells that the Model S uses were cycle tested at 0.5C (AKA fully charged from 0%-100% in 2 hours). Other Panasonic 18650 cells are cycled at 0.7C. The supercharger at peak power charges at ~1C (90kW of power to 85kWh of battery). In general charge rates peaking at 1C is perfectly fine for most 18650s (as in you will get the rated life of the cell).
http://www.teslamotorsclub.com/show...or-Model-S/page2?p=61317&viewfull=1#post61317
http://batteryuniversity.com/learn/article/charging_lithium_ion_batteries

As for the relative effects of different charging rates on battery life, I wasn't able to find data on that (there's plenty of data though that shows high temperatures and storage at or near 100% for long periods of time significantly degrades the battery).

Like Jason S says, there's data on the efficiency of various charge rates for the Roadster (that's easier to gather since you can do so with only a few charging sessions). Battery life characteristics is harder to gather because you have to do hundreds of cycles to do so.
 
It only charges at full rate for the bottom half of the battery. At 50% the rate is reduced by half and I believe it goes down even more as it approaches full. There shouldn't be any more deterioration than with a home charge.

What's bad for the battery is charging to 100% (range charge) and then leaving it sit at 100%.

Jerry,


I understand that the communication between a Tesla Supercharger and a Tesla battery is much more sophisticated than conventional fast chargers. However, do you know for a fact that when Supercharging in Range mode that the average current after 50% state of charge does not exceed the current during home charging in Range mode? Or stated another way, does the Supercharger really convert itself to a home charger after it reaches 50% state of charge?

Based on Tesla's statements I have little fear that Supecharging in Standard mode hurts the battery. Likewise Tesla is clear that charging in Range mode will definately accelarate the deterioration of the battery. While I seriously doubt that Supercharging in Range mode a few times would "murder" the battery, I'm just not convinced that Supercharging in Range mode would be no worse than home charging in Range mode.

Larry
 
Jerry,

I understand that the communication between a Tesla Supercharger and a Tesla battery is much more sophisticated than conventional fast chargers. However, do you know for a fact that when Supercharging in Range mode that the average current after 50% state of charge does not exceed the current during home charging in Range mode? Or stated another way, does the Supercharger really convert itself to a home charger after it reaches 50% state of charge?
Hi Larry, not sure what your point is as I believe you and Jerry are in agreement that supercharging in standard mode is no different to the car than AC (home) charging. The folks who used the SC's in Gilroy and let them sit for awhile noted that the charge rate continues to taper off as the battery fills up.
 
Hi Larry, not sure what your point is as I believe you and Jerry are in agreement that supercharging in standard mode is no different to the car than AC (home) charging. The folks who used the SC's in Gilroy and let them sit for awhile noted that the charge rate continues to taper off as the battery fills up.

I was under the impression that Jerry was saying the Supercharging in Range mode is not different to the car than charging at home. We all agree that the charging tapers off as the battery fills up. The question does it taper off to the same degree as a home charger?

Larry
 
It isn't that high-amperage is bad, it is just that a Roadster owner verified charging at 30-40 amps was optimal for that car.

Could charge at higher amps, but lose electricity to overhead like cooling. I don't think anybody has measured it and shared the results for the Model S yet.

Tom Saxton ( Roadster owner ) tested charging the roadster at different rates - to find out which was the most energy efficient.
Tesla Roadster Charging Rates and Efficiency - Tom Saxton's Blog
The testing had nothing to do with what was bad for the battery - it would take years and many cars to do those tests, and be very hard to isolate the variables. We have very little hard data on what is "bad" for the battery at this time. It is most probable that the charging rates supported by the roadster are indistinguishable in terms of battery degradation. All the other factors are likely to reduce any difference from charging rate into rounding error.
 
supercharging will not murder your batterie. i assume that you will immediately leave the supercharge and continue your travel. Even then charging in range mode will not hurt your batterie. But you will loose on time because the current will constantly drop and charging will slow down. better go off after 30min and head to the next supercharger. only charge high and sit will damage your batterie over time. the cells used in Model S 85kWh are even more stable as those used in the Roadster and in the 60kWh and 40kWh pack.
 
Last edited:
I was under the impression that Jerry was saying the Supercharging in Range mode is not different to the car than charging at home. We all agree that the charging tapers off as the battery fills up. The question does it taper off to the same degree as a home charger?

My understanding is that because of the spacing of the Superchargers (SC) you won't normally have to do a range charge using an SC. Doing a standard SC charge should cause no more degradation than doing a standard home charge because of the cooling ability of the Model S and the SC's reduction in power after 50% is reached. Presumably (needs confirmation) if you do a range charge in an SC the rate of charge will slow down to the same as a home range charge so it will (confirmation needed) take much longer to get that extra 10% of charge. As I understand it, the SC plan is to start charging when about 25% of the charge is left and charge to about 75% or 80%. (30 to 60 minutes), then drive to the next SC.
 
My understanding is that because of the spacing of the Superchargers (SC) you won't normally have to do a range charge using an SC. Doing a standard SC charge should cause no more degradation than doing a standard home charge because of the cooling ability of the Model S and the SC's reduction in power after 50% is reached. Presumably (needs confirmation) if you do a range charge in an SC the rate of charge will slow down to the same as a home range charge so it will (confirmation needed) take much longer to get that extra 10% of charge. As I understand it, the SC plan is to start charging when about 25% of the charge is left and charge to about 75% or 80%. (30 to 60 minutes), then drive to the next SC.

Thanks Jerry,

I agree that the practical aspects of Supercharging, and not waiting forever at the Supercharger, will render academic discussions regarding harming the battery moot. In other words, due to practical considerations there rarely would be a need to risk Supercharging in Range mode.

Larry
 
In other words, due to practical considerations there rarely would be a need to risk Supercharging in Range mode.

Larry
The only exception I can think of is when planning to leave the "Charger Net" before getting to the next S/C, and wanting to get as far as possible before having to do a slow-charge.
 
Now that people are finally getting to do some realworld tests of the Supercharger network (waiting for them patiently down here in Texas), are you seeing any any negative effects on battery life?
The impact is so negligible it'll take years and tens of thousands of miles to see any differences. Think of it as increased wear, not "damage".

Plus as I pointed before, you will likely still get the rated life of the battery using range charging + supercharging (what Tesla expects is ~70% capacity in 7 years and 100k miles), because that's how 18650 batteries are tested in the first place. But if you want to get more life out of your battery than what Tesla expects, shallower cycles will help (don't use range charge that often). Charging speed seems to have less effect.