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Max charge to leave at car for a week

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I will be leaving my x at the airport in Atlanta for 8 days. When I get back I will have a 200+ drive to get back home. I am trying to make it home as fast as possible so i am trying to determine how much is maximum charge that I can safely leave it at for that time period. Can I leave it parked at 90% for 8 days without putting too much strain on the battery? I expect 1-3% battery loss per day.
 
90% is a normal charge to value no matter what. I am not sure what the issue you are worried about is.

Unless you have a 100D and a tailwind, I doubt you are going to make the 200 mile return trip after losing 10% to 20% in vampire drain, so you are going to have to charge somewhere on the way home.
 
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Thanks for the quick reply. The 90% charge notch is the first notch in "Trip" notches. I know you aren't supposed to leave the battery fully charged for long periods so I just wanted to make sure 90% was ok to leave the car parked at. The most recent thing I read was that 70% was the ideal daily charge state for battery health. I know I have to make a stop to charge, but wanted to have as much charge as possible when i get back to make it to the supercharger that is 150 miles along my route without having to charge at the airport too. Also want to limit charge time.
 
you could make some changes to get less vampire drain on the battery as well...

1 turning off cabin overheat protection
2 Always Connected' must be turned off.
3 Energy Savings' must be turned on.


as far as long term usage, charge to what you need on a daily basis however less charge will equal more lifespan as you have read. Charging to around 70% will give you much more lifespan vs 90 but if you really need to use more then 70% of your battery then charge more. Also if you use less then you could charge less on a daily basis. Personally I charge to 60% daily but if I know I need to travel further tomorrow ill set my car to charge more tonight to be prepared.


Heres a chart showing a general example of how charge percentage of a lithium ion battery relates to they number of cycles you get. These aren't exact numbers for a Tesla but it gives you an idea of how reducing your daily charge limit can increase the cycle count.

Screen Shot 2018-05-18 at 10.08.43 AM.png
 
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The notch at the end, 90%, is the top of the daily charge level. The range charging starts after that.

There has been a debate for years about 80% being ideal. I see this quote from Jeff Dahn, a renowned battery researcher in Electrek that states he thinks that 70% is the ideal daily charge level. The manual states 70% to 90% for longest life. So going to 90% a few times is certainly not going to be a big issue.
 
I charged my Model S to 90% every night for five years, except when I charged to 100% for trips. No worries. Did you know that early versions of the firmware, before the slider was introduced, had only two settings “daily” and “trip”? The daily setting was 92%.

Whether you routinely charge your car to 80% or 90% may give a statistically significant difference after many years but it’s not clinically meaningful.
 
The ATL airport parking lots/structure has Chargers at no additional cost. They are slow (4-5mph) but that’s not a problem since most EVs will be plugged in for days. Just leave it plugged in and you’ll be at 90% when you return. Vampire drain will happen but once it drops 10% it will top you off again. You can also remotely set the charge to 100% the night before you return.
 
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