Actual risk to charge everyday at 100%?

[CyberGus]

There are two factors of cell degradation: discharge cycles, and the passage of time (“calendar” degradation). When simply resting, the cells degrade, in proportion to state of charge (SoC). Higher SoC leads to greater degradation, but the relationship is not linear, with a steep increase above 80%. Around 50% would be best, even lower if storing long—term.

Tesla will warranty a pack that degrades below 70% capacity, but you would be hard-pressed to hit that if you tried. So charge to 100% if you feel you must, but I think you’ll soon find it unnecessary.

I’ll likely set my charge point to the lowest of 50% for daily use, and go higher as needed.

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[Freemarket]

I’d prefer to have it at 90%, but Tesla seemed to change it to 80%, even on my Plaid, which used to be up to 90% for daily use. I just don’t like seeing my battery dip into the 60’s. I am however abiding at 80%. Not worth overdoing it if it’s not needed for sure.

 

[CyberGus]

The thing that is confusing is that we never have to worry about this for laptops and phones.

My MacBook holds at 80% when I have it on power most of the time.

 

[sakabaro]

We should probably do a cybetruck Austin hang as we seem to be all in Austin, TX lol.

 

[sakabaro]

> There is a chart from a study done on degradation based on max charge %. Google Jeff Dahn, who Tesla hires for battery chemistry research. There are lots of articles and videos discussing these topice.

Do you have a link to the chart? Would love to nerd out.

 

[CloudNull]

Great thread. Feels weird not getting the charge to 100% but understanding the reason behind it makes sense. I honestly had no idea the benefits of not charging it to 100%

 

[AlmostHuman]

Like others have said, leaving it at 100% is not great. If you want to leave the house with 100% you could always set the charging start time so that it will finish charging to 100% very shortly before you want to leave. For example we are taking off tomorrow AM for a comping trip. Currently the truck is sitting at 48% plugged in. I set he charge limit to 90% and set the scheduled start time so it will finish charging about 10 minutes before we are going to leave. I do this for long trips as well but sometimes set it to 100% charge limit. I try to never let the state of charge be over 90% for any long period of time. I think in the end you should do whatever works best for you. If you do end up charging to 100% every day I'm sure many of us would be interested to see what your max range is like in a year or so.

 

[GatorCyber]

> There is a chart from a study done on degradation based on max charge %. Google Jeff Dahn, who Tesla hires for battery chemistry research. There are lots of articles and videos discussing these topice.

Do you have a link to the chart? Would love to nerd out.

It's a lot of info and variables, so it's really something you need to research yourself. It may also have info on temperature-cold has almost no degredation and desert climates are the worst. I think this video has the info I'm recalling:



Summary:

For simplicity: Don't stress and just keep limit at 80% unless absolutely necessary and limit the time below 20% and above 80% (schedule charge limit to peak right before you leave).

If you like to optimize: Batteries like to stay at or near 50%. An example would be if you drive 20% daily, set your charge limit at 60% so your battery stays between 40%-60%. Also, don't store car outside in hot climates as batteries degrade more in desert climates and not at all in cold climates.

You'll likely stop doing 100% everyday as you learn about it.

I used to keep my Model 3 at 80%, but after watching this I keep my new Model X at 55% and plug in whenever I'm under 50%.. I only make short trips a few times a week, and the majority of my miles are road trips. I don't even go over 80% before road trips anymore (used to do 100% for cheap home rates) unless necessary, plus my preferred 1st stop I like to arrive with under 15% for faster charging speeds.

 

[Giskard]

Somewhat related to this thread, Recurrent allows you to track your battery health over time. Sadly they don't support the Cybertruck (yet), but I've had it monitoring my Model Y for over a year and I like having access to the data. I generally keep mine set to 70% for daily driving, bump it to 80%-90% right before longer trips, and do have to charge to 100% occasionally (towing my camper). It plots where your battery pack health is in relation to others based on several factors including charge cycles.

https://www.recurrentauto.com/for-owners#how-does-it-work

 

[ChristoN]

Is there a way to quantify that pull between a 80% and a 100% charge? Is it just around 20% worse or like exponentially worse?

The thing that is confusing is that we never have to worry about this for laptops and phones. Despite being the same lithium-ion technology. You charge it up to 100% and accept the battery degradation.

My iPhone and MacBook show under system settings and then under battery health, that the maximum capacity is reduced. We don’t worry about it but you can see that charging it to 100% does take its toll. My MacBook Pro is only two years old and the maximum capacity is 89%

 

[sakabaro]

> My MacBook Pro is only two years old and the maximum capacity is 89%

Would you have charge it to only 80% if the degradation was instead of 89% only 95%?

 

[pricedm]

Why charge to "100% every day?"

I don't understand this situation.

 

[sakabaro]

> recurrentauto

Yeah, it will be sweet to see nerd data about Cybertruck battery pack.

 

[Tiberius]

Why charge to "100% every day?"

I don't understand this situation.

Been driving electric for many moons and its always been a recommendation to normal charge to 80%, but its OK to charge to 100% on road trips.
Two biggest reasons I've found are:

1. Charging from 80-100% takes twice a long as going from 60-80%
   That's just how charging works, a bit like filling a bucket with water, to start with you can go as fast as the hose allows, but near the top you have to slow down otherwise water goes everywhere
   This is more important on road trips. The car will try to arrive at a supercharger station with 10-15% charge so that it can recharge faster, then it slows down the fuller it gets. You will only get 250K <50% and it tapers down to 20K or less. By 90% it's down below 10K. Those last few percent seem to take forever.
2. Charging to 100% means no regenerative braking - there's nowhere for the energy to be stored. You will see this even at 95% and is a surprise for many people.
   Once it gets <90% it will regen normally. The issue is the same as charging, it can't get the power back into the battery fast enough.

 

[cybercuh]

I charge it to 95 every night, I'll be taking the depreciation hit, let the next owner deal with the battery issues lol

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