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Best Charging Practice to achieve best battery lifetime.

Best Charging Practice to achieve best battery lifetime.

I read the manual, it really doesn't say much.
One tip is to keep your car plugged in during extended storage.

I heard two approaches

-> Short charges, charges your car frequently, basically avoid long charges so the battery is not heated too long
-> Long charges, avoid charge your car frequently

Other tips that I can concur with without questions:

-> Avoid using fast DC charging (I know, people will argue, but I do agree fast DC charging will heat up battery significantly)
-> Avoid fully discharge your battery
-> Avoid fully charge your battery
-> Avoid leaving the car under extreme weather (Too cold or too hold)

zyuaninc | November 29, 2018

Another question:

Does model 3 has thermal management system like model S?

Earl and Nagin ... | November 30, 2018

Short charges around 50% is best. Short charges above ~80% are about the same as long charges.
It really doesn't matter much, the other tips you've found are the key things although DC fast charging and extreme weather aren't that big of a deal.
Yes, Model 3 has the same (or better) awesome thermal management system like Model S. This is why fast charging and leaving car under extreme weather isn't an issue.

wlrobins | November 30, 2018

I'm a new Tesla owner, so the question is: the car will be garaged for 1 week while I am on vacation so should I leave it plugged in during that time or not?

Bighorn | November 30, 2018

@wlrobins
Tesla says yes. Doesn’t really matter enough to be a concern.

jordanrichard | November 30, 2018

Not complicated. Leave the car plugged in all the time. Don’t let it routinely get below 20% and charge to what will cover your daily routinely plus a healthy buffer, but don’t routinely charge to 100% and let it sit there for hours on end.

Don’t worry about temperature, the BMS will take care of that.

PT733 | December 1, 2018

AFAIK, a daily topup to 60% for short trips, and staying above 40% if possible is best? (ignore the estimated range guessometer). Leave plugged in set to 60% and the mains power might heat or cool?

On road trips, if you can top-up every 100 miles then 75% to 45% should be excellent (Accubattery on Android shows 12% of a wear cycle for this 30% depth of discharge -- 30% of 300 miles is 90 miles)

Avoid fast acceleration below 30-40%?

I wouldn't worry about charging to 90% before an occasional road trip.

The lower power urban superchargers might be better for the battery than the 120kW superchargers? e.g. 80kW is a 1C charge rate. 7kW at home is about C/10 (and enough power to heat the car)

https://www.google.com/url?q=https://batteryuniversity.com/learn/article...

Bighorn | December 1, 2018

@PT
Mains does not heat or cool of its own accord. It would replenish charge however if the battery heater were used by the app or if overheat protection were drawing the battery down sufficiently or the battery were being cooled. There won’t be a big difference in charge rate between an urban charger and a supercharger if the SOC is above half. Fast acceleration will start to be limited by the BMS at lower SOCs automatically. Dots shoukd appear on the power drawn side of the meter.

CASEMAN | December 3, 2018

Elon Musk's Tweet from a few days ago:
Elon Musk
@elonmusk

Nov 30
Not worth going below 80% imo. Even 90% is still fine. Also, no issue going to 5% or lower SoC.

jordanrichard | December 3, 2018

Just don't make a habit like Teslaloop did and that is routinely run the battery down to near empty, supercharge back up to 100, drive it down to near zero, SC back up to 100, "rinse and repeat"

Bighorn | December 3, 2018

@CASEMAN
Elon later concurred that the recommendation by his battery expert, Jeff Dahn, to charge to 70% was better, but probably not noticeably different to most. But the OP is asking for best practices for preserving capacity.

andy.connor.e | December 3, 2018

Optimal battery health is between 30%-70%. Next tier is 20%-80%.

If you do not plan on owning the car for 10 years or more, please do not worry about this aspect. But then again be conscious of it because of when i buy your used Tesla.

geno.kearney | December 3, 2018

At delivery they told me set it at 90%, and charge it when down at 40-50%. Only 100% when tripping. That's what I do.

Geno

aasandsas | December 3, 2018

I was told at delivery that charge upto 90%. Answers are all over the place but if most people play and charge between 30-80% regularly and occasionally 10-95% it should be fine.

Tesla does give warranty for 8 years/100k for MR on basis it shouldn’t deteriorate below 70%. I mean no way one should abuse it but still for practical purposes there is no right or wrong answer here. My driving patterns are not linear but that’s just me.

Bighorn | December 3, 2018

@geno
That’s the dumbed down version from the script of hourly workers, possibly temps if you had an end of quarter delivery. OP is looking for some thoughtful consideration.

geno.kearney | December 3, 2018

Well it works well for me. When I occasionally go to 100% it charges to 310 miles. This is after 5,000 miles.

Bighorn | December 3, 2018

@geno
It will work well for some people. I wasn’t particularly pleased after 200,000 miles in my Model S, but that’s me. Luckily, I got a new battery. Someone with plans to hold on for 10-20 years probably also has different goals. My Model 3 was down from 310 to 299 after 23k miles/2 months.

andy.connor.e | December 3, 2018

Alright let me try again.

Battery is sensitive to high level temperature changes high and low, which the BMS takes care of relatively well. Keeping your Tesla plugged in if you have that luxury will eliminate the charge loss due to BMS if you live in very hot or very cold environments.

Charging speed at home will not have a significant impact, but supercharging frequently will. If higher charging rates use more current, it will induce a hotter cell. Should limit supercharger use to their intended purpose, which is to charge during a long trip. (again, if you have the luxury of charging at home)

Likewise with the high charging current, you should be conscious of the opposite of discharging your battery. Or rather, using your car. "Flooring it" will use a massive amount of current, and the optimal advise here is do not "floor" your car to preserve battery health in the long run.

I have read alot about battery cell health, and you can extend the battery health by keeping it as close to 50% as possible. You can get more cycles the less you let it venture away higher or lower than 50%. I dont think in a convenience sense or practical sense you should keep your battery between 40%-60%. If your commute warrants it, 30%-70% is what i would consider optimal. 20%-80% is still extremely good. Definitely do not charge to 100% or let it drop to 0% frequently if you can avoid it.

Once or twice will not affect anything. These scenarios are based on doing that every single time you charge. Flooring it constantly. Hope this can help, take care of your car and it will last you 20 years.

Sparky | December 3, 2018

Don't "floor" your Tesla. Kind of reminds me of an old poem about sailing ships:

"A ship in harbour is safe, but that's not what ships are built for"

:-)

andy.connor.e | December 3, 2018

Its to achieve optimal battery health. We all know that is impossible due to the law of Tesla.

zyuaninc | December 3, 2018

So after reviewing your comments and advice, here is what I gather and intent do to with my model 3.
My plan is to keep it for at least 8 - 10 years, so capacity matters to me.

-> My regular commute is 40 miles round trip.
-> For regular commute, I charge model 3 at home. I charge the battery from 40% to 75% every 2 days. A
-> For long weekend trips (For example, driving between LA and San Diego), I charge it to 90%. Then supercharging it whenever the battery is going below 40% (Will not go down further less than 30%)

Thank you all for the advice.
@Bighorn, you understand my point and very good advice. Thanks.

shawncordell | December 3, 2018

You can count on the manual, Elon and bighorn. Disregard the rest.

terminator9 | December 3, 2018

I do not think about this. I am sure the way the recommendations are designed, it is to extend the battery until the warranty period. Do whatever you want to do so if it fails (looses the cells) sooner, at least it is under warranty.

shawncordell | December 3, 2018

Great advice!

/s

terminator9 | December 3, 2018

>> Will not go down further less than 30%.
On longer trips if you are at 0-20%, it will charge faster. The more you have left, the slower it will charge at SuperCharger. It does not matter unless you do it every day. If going below 30 was bad, the software would not let you do it as people would take Tesla up on their battery warranty often.

terminator9 | December 3, 2018

Think about when the Standard battery comes out. Staying within 30%-70% will give you may be one daily work commute before you have to charge again! :) Don't over analyze the battery charge cycles and enjoy the car!

terminator9 | December 3, 2018

On the app these is a CLEAR indication on the battery slider at 90% for daily.

thedrisin | December 3, 2018

@terminator9. Those owners won't even make it round trip commute in the cold weather at those limits!

geno.kearney | December 4, 2018

@terminator9

+1

mikes | December 4, 2018

I put on about 60 miles a day, will have about 30-40% left, now with cold temps usually closer to 30%. Then I charge it over night to 70% and keep doing this every day. As temps dropped below freezing I noticed the battery being cold in the morning, resulting in limitations, mostly regen. So I set the charge rate down to 20amps and start charging at 11PM or midnight. This will keep charging the battery for about 5-6hours every night and the result was a warmer battery and less power limitations every morning. I also believe that charging slower is better for the battery.

terminator9 | December 4, 2018

Charging slow is better for battery but not the way you are thinking. There would be no visible difference to the health of the battery between 20 amps and 30 amps. Might as well change from 110 at 2 miles an hour if it is so good. Now, if you use a supercharger every day @ 200 miles/hour rate, that will be a noticeable impact on the health of the battery.

rsingh05 | December 4, 2018

Interestingly,extreme supercharging twice daily by Tesloop degraded the range by ten percent, but there was no further degradation after that.

I've had my car for a month now and I charged it nearly everyday at work. Supercharging only for long trips. I will go with Elons recommendation and say up to 90% is fine if you can bear the slow charge time for the last 10% from 80-90%.

No need to overthink or follow conventional.wisdom about Li-ion - just go with the official recommendations and enjoy the car!

jjgunn | December 4, 2018

andy.connor.e | December 3, 2018
Optimal battery health is between 30%-70%. Next tier is 20%-80%.
------------
I keep my battery between 30% - 80%

But I have 10,500 miles in 5 months. How am I doing?

zyuaninc | December 4, 2018

@jjguun, yeah, how are you doing with your battery capacity?

jjgunn | December 4, 2018

Haven't noticed any loss of range or anything.

Wish we could have 600 Mile range. :-)

michael | December 4, 2018

@mikes

Interesting idea. I think I'll test out your theory - less amps and longer charging times - for more warm battery in colder climates.....good idea.

Bighorn | December 4, 2018

Low and long won’t necessarily generate warmer temps—often the opposite, depending on the temperature.

jjgunn | December 4, 2018

Charging lined out instead of as fast as possible.

That makes a lot of sense in cold weather.

zyuaninc | December 4, 2018

I think we are only going to do this in the first year.....

Next year we are all going to be like "whatever, it's just a car."

thedrisin | December 5, 2018

Is there any actual real data comparing the different charge scenarios and the effect on degradation rates or is it hypothetical?

ian | December 5, 2018

Something I haven't heard: if you really are having trouble making the 30-70% thing work. Is it better to charge to 75% or let it go down to say 20-35%. Basically, when it comes to batteries, is a bit more or less of a charge better or is either extreme the same?

Sparky | December 5, 2018

@zyuaninc; of course you're right. There will always be those who want to stay within a theoretical best practice but we'll all be better off if we don't overthink it and just charge to 100% only when necessary. I charge mine to 70% daily, 90% if I'm going skiing. I haven't had to charge it to 100% yet and maybe I never will. Will I notice the difference between .8% degradation and 1.2% degradation next year? Probably not.

andy.connor.e | December 5, 2018

@jjgunn

You're doing good. The results of what you're doing will not be noticed in short time. Its after 5 years you will notice your maximum capacity has not moved much at all.

mikes | December 5, 2018

@Michael
I'm wondering if you find that to work for you as it works for me.
@BigHorn
How would longer charge at lower rate cool battery? As far as I know when you run electricity thru a conductor it will always create heat.
My slower charge for longer time seems to work as I get no snowflake and no regen limited warning in the morning when I charge this way. Charging at regular speed without timing the charge gives me usually both. Charging fast on cold battery to pre-heat the battery can take its toll on the battery over time.
Car usually sits 9 hours a day in town, not plugged in, and will have snowflake on screen even with now 20 degrees higher temps than in the morning. This makes me believe my theory is correct.

Bighorn | December 5, 2018

Depends on the ambient temperature. Simple thermodynamics. The dedicated battery heater on the Model S is 6 kW. That is 25 A/240V. The incidental heat of charging isn’t nearly as efficient. How much energy do you think it takes to warm half a ton of batteries by 40 degrees when that heat is equilibrating with the environment? Low current is like trying to heat your house with a blow dryer. Better have a lot of blankets cause it’s never getting warm.

vmulla | December 5, 2018

I'm almost at 26K, had the car for 10 months now. I set my charge capacity at 90% unless I'm headed out on a road trip, then I put it to 100%. I keep the car plugged in at every opportunity. I charge at the Superchargers as recommended by the car's computer. I have often taken longer breaks and charged it up to 100% on DC (Supercharger), but more often I just charged up enough to get me to the next stop as recommended by the car.

... And my car gives me a range of 278 miles at 90%, it was giving me 279 when brand new. I say that's incredible as far as c battery longevity goes.

So, just don't think too much, let the computer tell you what's right and everything will be just fine. Even Elon's tweet and the owners manual say as much... My observations just back them up with real world numbers.

vmulla | December 5, 2018

And I'm in the Washington DC area where we see a decent amount of temperature swing through the seasons.

jjgunn | December 5, 2018

andy.connor.e | December 5, 2018
@jjgunn

You're doing good. The results of what you're doing will not be noticed in short time. Its after 5 years you will notice your maximum capacity has not moved much at all.
----------
Thanks! But today I let my SOC drop to 25% - Damnit! Tried not to go less than 30%!

All good, I charged "slowly" at an Urban SuCh'r (72 kW) ;-) to 81%

vmulla | December 5, 2018

Oh, I often go below 10% charge. Probably dozens of times. But there was hardly any effect on how my battery is holding up.

At this rate I expect to have less than 5% range loss over 200K miles.

Iwantmy3 | December 5, 2018

During the summer I was charging twice a week. Once to 100% for weekend trips and once to 85% to meet my weekly needs. In the cold weather, I am charging more often (every 2 or 3 days). 6 months and 14000 miles, my battery showed 307 miles @99% charge. So far so good. Although I was getting as much as 316 miles back in July at 100%.

Does ambient temperature have an effect on the maximum charge level or rated range?

mtmodel3 | December 5, 2018

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