Charging cycles vs Battery life

[RichGPilot]

Do i understand correctly that a high number of charging cycles will reduce battery life much the same as always going to 100%

 

[Adrien]

100% will do more damage....over time of course. High charge cycles is basically equivalent to how many miles you put on the car.
If you follow this graph you can see that most lose 5% fairly quickly, but then it seems to level off quite well. These are doing better than even Tesla predicted.

Charge cycles will be equivalent to the above in a general sense. So in conclusion you're not right, but you're not wrong either. Do you have a scenario you'd like to bring up? That might help with the discussion

 

[David99]

Many things are bad for battery life. Charging to 100% all the time isn't good. Using a battery a lot is not good either. Warm temperatures are not ideal. Using very high power isn't good. Using it at very cold temperatures isn't good. Tesla has built in several system that keep the battery 'healthy' and prevent damage.

I have 81k miles and two years on my car. In hot climate and I charged to 100% many times. My battery is still holding up very well. It actually seems to hold up better than others. My advice: don't worry too much about the battery. The car will take care of it on it's own. The battery will last you a very long time.

 

[RichGPilot]

I guess I'm just trying to understand it. I was thinking that lower percentage charges require more frequent charge cycles. So what your saying is that is less damaging.......got it. Thanks.

 

[David99]

I guess I'm just trying to understand it. I was thinking that lower percentage charges require more frequent charge cycles. So what your saying is that is less damaging.......got it. Thanks.

According to an expert, the degradation is almost the same if you cycle a battery 100 times from 30-60% or 50 times from 10% to 70%. In other words more shallow cycles don't help much with battery life. The same expert said that you should always only charge to the level you need. It's better to charge only to 90 instead of 100. It is better to charge only to 80 instead of 90 and it is better to charge only to 70 instead of 80.
My daily charge level is between 70 and 80.

 

[Doug_G]

This has been extensively studied by Tom Saxton. He's done battery capacity surveys for the Tesla Roadster, Leaf, and Model S. For the Tesla vehicles, loss in range correlates extremely well with pack cycles. There is also a very strong correlation to mileage since most pack usage is spent moving the car. He found no correlation with temperature, probably because Tesla actively cools their packs. Leaf has an impact in hot climates though.

Original thread: Tesla Model S Survey by Plug In America

Survey page: Plug In America

 

[RichGPilot]

Thanks Dave and Doug

 

[JRP3]

I have 81k miles and two years on my car. In hot climate and I charged to 100% many times. My battery is still holding up very well. It actually seems to hold up better than others.

What we may be seeing is people with higher mileage and a lot of 100% charging have better capacity calibration than those with shallow cycling.

 

[David99]

This has been extensively studied by Tom Saxton. ... He found no correlation with temperature, probably because Tesla actively cools their packs.

I looked at the survey and I even added my car just now but I couldn't see any reference or questions regarding temperature. Does he go by average temperature of the location?

 

[Doug_G]

Yes, he uses climate data for the location. I'm going from a presentation he gave at TMC Connect. Look at the LEAF study, it probably has more detail since there is a correlation with temperature due to lack of proper pack cooling.