2 Options for Battery Longevity

[DenverLucid]

Just picked up my AT and am loving it so far.

I have two options for charging and am wondering what is better for the battery...

1. At home I have 120v charging and the 8-12 hours it is parked will cover the daily usage as my commute isn't that long. In this scenario I would charge daily or nearly daily and keep the battery between 40% and 80% at all times. For this to work I would need to charge almost daily as my usage is a little below what I can add overnight.
2. At work I have 240v charging. In this scenario I would charge once a week and run the battery down to 25-30% then charge it back up to 80%.

Is there a downside to charging daily if it is at 120v and never goes above 80%?

Thanks for your thoughts and advice!

 

[DeaneG]

I think the main difference you'll notice is that you are paying for your electricity at home, vs. work paying for it.
NMC lithium-ion batteries like the ones on our Airs have the lowest degradation when kept around 50% state of charge. But realistically, either scenario you mention is fine, and I would do whichever is the most convenient or cost effective for you.

 

[suchluke]

Any charging option will be fine as long as you try to keep it between 20%-80%. It's even fine to go 15%-85% as long as it's not for extended period of time and outside temperatures are mild. Level 2 charging is perfectly fine. Heck even Level 3 is shown fairly safe for the battery as long as you staying within the 20%-80% SoC.

 

[DenverLucid]

Good point. I own the business and pay the electricity bill for work too but it is commercial rate and will get wrapped into the overall electric bill so it becomes a business expense.

I just want to preserve the life of the batteries as much as possible. I will rarely (2-4 times a year) use DC charging only go over 80% (2-4 times a year).

I can run the car down to the 30-40% mark and then charge daily. It should be possible to keep it between 35 and 65% most of the time.

 

[DeaneG]

Good point. I own the business and pay the electricity bill for work too but it is commercial rate and will get wrapped into the overall electric bill so it becomes a business expense.

I just want to preserve the life of the batteries as much as possible. I will rarely (2-4 times a year) use DC charging only go over 80% (2-4 times a year).

I can run the car down to the 30-40% mark and then charge daily. It should be possible to keep it between 35 and 65% most of the time.

All good! The car's battery will slowly degrade with time no matter how carefully you manage it ("calendar degradation"), so there's no substantial payback to super-careful behavior that reduces the utility of the car or your enjoyment of it. Even DC fast charging, according to Lucid, seems to not be a big issue. This was a surprise to electrical engineers like me who paid attention in the past. Just don't leave the car below 20% or above 80% for very long periods of time.

 

[californiaboy935]

All good! The car's battery will slowly degrade with time no matter how carefully you manage it ("calendar degradation"), so there's no substantial payback to super-careful behavior that reduces the utility of the car or your enjoyment of it. Even DC fast charging, according to Lucid, seems to not be a big issue. This was a surprise to electrical engineers like me who paid attention in the past. Just don't leave the car below 20% or above 80% for very long periods of time.

Have pretty exclusively charged on DC fast chargers and haven’t seen any appreciable loss of battery life, even over 60k miles.

 

[borski]

Don’t stress about it, and charge when convenient, assuming rates are the same.

 

[illopp00]

Temperature and calendar aging are the most significant effects on battery health. There was a recent study released that showed that in the real-world batteries do much better with drive cycle type discharging and recharging than in the lab where they run constant current to discharge. You want to keep away from the extreme ends of SOC in above 85 and below 20 DEG F temps as well. But I used the API to check my car after 2.5K miles, then now at 3.8K after Chicago winters where I had it down to 3% in 15 deg f weather and DC fast charged, and it shows no differences.

 

[segbrk]

No idea how big a factor this is, but charging from 120V is probably going to have more loss (waste as heat) than 240V over a long period of time. Might not be significant enough to care.

 

[DreamTour]

No idea how big a factor this is, but charging from 120V is probably going to have more loss (waste as heat) than 240V over a long period of time. Might not be significant enough to care.

~13% less efficient fwiw.

 

[Dog poop]

I say charge how you want. Realistically are you asking a question that really doesn’t impact you unless you plan to keep the vehicle until it’s got 120-150k miles on it. And at that point, what’s 10-15% loss on the range of an Air???

Famous words to live by, charge it how you want and drive it like it wants to be driven. Enjoy bro!