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How often do you recharge?

How often do you recharge?

Assuming you want to maximize battery life, is it best to recharge (not fully, say to 80%) every night or when you get down to a certain level (as a ICE car would)?

Anthony J. Parisio | June 2, 2016

Every time you come home. Lithium batteries are not like any other batteries. They do not like to be fully discharged or fully charged. I would not want to get close to the 20% mark. First 20% of charge and the last 20% are dangerous areas for a lithium battery. Not to get too technical, what happens in those two areas of charge is the cells are very unpredictable. Each cell may be charging at a different rate than others. A cell that finishes for sooner then the rest may end up being damaged permanently. My advice is not to do it. Just charge every time you come home.

bruntonma | June 2, 2016

I think Tesla recommends 90% charge as a daily maximum, don't they?

douglasstuckey | June 2, 2016

Yes, 90% charge every day gives you an almost full tank every morning. Works for me.
LOVE MY TESLA

Anthony J. Parisio | June 2, 2016

It has been discussed here that Tesla's 90% is really only 80% .

Bighorn | June 2, 2016

I think it's probably more accuate to say that 20% is really 30% and that 90% is 90%. Either way, it's immaterial to the battery's efficiency or longevity. Avoid keeping the battery at near 100% or 0% for any extended periods, Beyond that, one is being unnecessarily OCD/neurotic.

EVRider | June 2, 2016

I don't drive much on a daily basis, so I don't plug in every day. I charge to about 85% when I get below 80 remaining miles or so, unless I need to charge sooner because of travel plans.

Galve2000 | June 2, 2016

I usually charge after every 200-210 rated miles of use. usually once a week in warmer months, sometimes twice a week in colder months.

Sometimes I'll plug in more once more per week even in warmer months.

if say I have an 85 mile drive and only 100 rated miles in the battery. can I make the drive? sure... but I won't have much milage left when I reach my destination. I could stop at a SuperCharger along the way for 10-15 minutes too, but it is honestly more convenient to drop off the car at a Destination charger. Especially if I have guests in the car. When it's just me and family, sometimes we will hit the SC.

I live in a condo in NYC and have limited access to Level 2 charging. But I make it work.

mjwellman | June 2, 2016

@Galve2000-That's interesting. Basically you are treating your car like an ICE vehicle because of where you live. How long have you been doing this? Have you seen a drop in your rated mileage?

Galve2000 | June 2, 2016

I've been doing this 11 months and 12,050 miles on the ODO when I got into the car this morning. I have not seen any drop in my rated range.

I typically get between 241 and 243 rated miles at 90% and I have found no rhyme or reason to the rated miles number. I used to think I got higher rated range at level 2 at my summer home 240 V x 40 amps rather than at a SC or a local Destination charger which is 208 V x 40 Amps but I stopped by Newburgh SC on the Sunday before last and there it was again.. 243 Rated Miles at 90%

it has been many, many months since I have charged to more then 90%

My car was in for the 1st annual service last week and took longer than expected due to an issue with the pano roof. I put nearly 400 miles on the loaner Tesla gave me over memorial day weekend. So today I would have been closer to 12,450 with my car but it was nice to drive around in an old Dolphin Grey with coils, and no autopilot. I didn't even use cruise control much b/c wasn't sure if it would be traffic aware and didn't want to test the theory.

hojo8 | June 2, 2016

Now that I am retired, I typically drive only 50 to 75 miles a week. So usually I would only need to charge one day a week.
However, I read here that "A connected Tesla is a happy Tesla" which would suggest that I should keep the car plugged in all the time it's sitting in the garage even if its not charging.
Am I understanding this correctly?

jordanrichard | June 2, 2016

Every day, regardless of miles driven. though I once did what Galve2000 does, but I decided that in the event that I had to hit the road unexpectedly, I want the most range available at all times. I typically charge to 80%.

Opafiets | June 2, 2016

My understanding is that the batteries are happiest and live longest at 50%. And that a plugged in Tesla is a happy Tesla. :-)

If so then charging to perhaps 60% each day, using down to 40% each day and charging overnight back to 60% is ideal (and yes, a bit OCD).

buickguy | June 2, 2016

Nightly, to 90%, whether I need to or not. Nightly charging is a habit now.

damonmath | June 2, 2016

I plug in every time I pull into the garage. I charge to 90% (max daily) at midnight. I have charged to 100% a total of 4 times and have never needed or used a Super Charger. I have 30k miles after 17 months and max charge is 263 miles.

monisone | June 2, 2016

A plugged in Tesla is a happy Tesla - I charge every night to 70% (irrespective of my use). The day i have longer trips i charge more 90/100% depending on how far i am going.

jordanrichard | June 2, 2016

Opafiets, where does your understanding of 50% come from. Looking at the charging screen, 50% is the min. amount you can charge to.

Eletrek | June 2, 2016

I've been charging to 80% every night since Dec. 2012. Started with 265 on max charge and max charge was 260 two weeks ago for a long trip. Way to many people regularly hand-wringing and whining about charging and battery durability in this forum. Just relax and enjoy the ride.

bdambrosio | June 2, 2016

Elon Mush commented in response to a question at the shareholder meeting that the Model S battery was designed to "be cycled weekly" (as opposed to the storage battery, designed to be "cycled daily".

I'm sure "cycled weekly" means deep discharge, not a simple topping off, but still, that seems to conflict with the conventional "charge daily" wisdom. On the other hand, having lived with an e-Golf as my primary driver for a year, it's hard to predict the night before when you might do more driving than anticipated.

In addition, my limited knowledge of Li Batteries (electronics nerd since childhood, Phd in EECS, DIY electric mountain bike with 70 mi. road range, but still consider myself a NOOB), tells me if you limit charge to 4.1 V/cell (~90-95%), topping off every day is much better for battery life than waiting to charge once a week. It's forcing that last little bit in that damages cells.

bdambrosio | June 2, 2016

Musk, sorry. btw, Model-S #1442xx, the wait is agonizing!

Bighorn | June 2, 2016

Cycled weekly means designed to go through 100% SOC or about 265 miles a week--doesn't matter how.
Doing that seven times a week powering a house would shorten its life and risk the 8 year guarantee.

SUN 2 DRV | June 2, 2016

Bighorn +1 Exactly... you said it very clearly and succinctly...

Take how many miles you drive a week, divide by 265 and that's how many "cycles" you put on the battery each week. It's how many kWh you push into the battery each week and not how many times you plugin and press the charge button.

AoneOne | June 2, 2016

One of the great pleasures of the Model S is the freedom to ignore the "fuel level" during daily use. Every morning I leave with a full tank and routinely ignore the remaining charge as I go about my day. The price of this freedom is plugging in every night and charging to 90%, which has cost me a few seconds and 2% of the battery capacity over 2 1/2 years and 43K miles.

Not only does this routine meet my everyday needs but, if an emergency should arise, I'll still have plenty of range to get to the nearby superchargers 60-70 miles away from home and get on the road without first recharging.

This car was meant to be used, not babied. I use it.

brec | June 3, 2016

From the Owner's Manual:

"The most
important way to preserve the Battery is to
LEAVE YOUR Model S PLUGGED IN when you
are not using it. This is particularly important if
you are not planning to drive Model S for
several weeks. When plugged in, Model S
wakes up when needed to automatically
maintain a charge level that maximizes the
lifetime of the Battery."

Can anyone make sense of the last sentence? AFAIK when plugged in, the car wakes up to check if the charge level has vampire-dropped more than a few percent from the set level, and if so, charges to the set level. The best I can infer from the statement is that since the recommended daily charge level is between 50-90%, all it's saying is that 50-90% maximizes battery lifetime.

vp09 | June 3, 2016

Brec, I can't make sense of it-- it suggests that keeping the battery charged to some high level is best for battery life. We read elsewhere on this Forum that JB Straubel said keeping the battery between 20% and 80% charged is best.

I'm not seeing how plugging in once a week versus every day makes a difference, if battery charge is above 20%.

And then we have the conflicting interest-- Tesla wants to avoid having any report of an owner running out of charge-- so it is in their interest to have all Teslas at full charge, even if it degrades our batteries sooner.

vp09 | June 3, 2016

Sorry, keeping it between 50% and 80% is best, and stay away from running it under 20% or over 80%, except if you really need that range. That's what I took away from JB Straubel's comments.

Galve2000 | June 3, 2016

of all this I would stress mostly the "a plugged in tesla is a happy Tesla" credo.

They have developed very sophisticated battery management systems for these batteries. plugging in the car will allow these systems the freedom to preform optimally. They can pull "shore power" to heat or cool the battery as needed, they can discharge the battery slightly knowing they have a power source available to replenish this depletion as necessary...

It sounds like some of these forum members are lusting for a PhD in battery chemistry and management. I get it, I really do.. i'm a nerd who wants his Model S battery to last forever. I am, like many of you, supremely confident in my knowledge and my understanding on all things Model S.

but there really is no need to overthink this. let the battery management system do its thing.

is 50% charge probably better for battery longevity than 90% in the long run? probably. but not in a way that becomes practically meaningful until you reach something like 400,000 miles of driving (I picked this number myself btw)

but you have to balance that with real world scenarios where a 50% battery only gets you roughly 100 miles of range between fill ups and in an emergency, that might not be enough to make the car practical. Tesla is staffed with some very smart people who have been doing this a fair amount of time. they have thought this through.

charge to 90% as often as you can. charge further only if you need the range to get to where you need to go. keep the car plugged in as much as possible ("a plugged in Tesla is a happy tesla")

3 simple rules.

follow them. they will get you well past 100,000 miles. they may not hold so well at 400,000 miles but by then I suspect your trusty Model S will have found a new life as high end aluminum razor blades they sell on Madison Avenue and most of us will be on our second, third, or hell even 4th Model S by then.

ok ok you want to be a more proactive Owner?

Fine.

set it to 80% as often as possible and keep it plugged in as often as possible. charge beyond 80% only as often as needed.

Happy now?

vp09 | June 3, 2016

Galve2000: I agree with you!

I have a situation maybe different from most of the rest of you-- I'll be paying up to 48c per kWh, no time of use metering. I can't have solar panels. SolarCity turned me down. They said it was not their decision-- it was the regional authority. Too much shade on the roof.

I live 3 miles from work. So I'm not probably fitting the profile of the typical Tesla driver.

jordanrichard | June 3, 2016

vp09, there is nothing in that paragraph from the owner's manual about leaving the car at a high SOC. IT just siply say to leave the car plugged in, when not in use. The reference about it automatically is as it also said, what will happen, due to vampire loss. We went away for a week and when the range had dropped I think it was 10 miles, the car charged itself back up.

vp09 | June 4, 2016

Thanks Jordanrichard. You are right. Also maybe it is to be plugged in in case of auto updates, so as not to miss them.

brec | June 4, 2016

It's not necessary to be plugged in to receive software updates. I received two of my last three away from home when not plugged in.

Galve2000 | June 8, 2016

My car is not plugged in very often as most but I often get software updates well before some other forum members who plug in diligently. Updates are independant from charging I figure.

mrspaghetti | June 8, 2016

@Bighorn Avoid keeping the battery at near 100% or 0% for any extended periods, Beyond that, one is being unnecessarily OCD/neurotic.

+1

acegreat1 | June 8, 2016

What's "extended periods". Example; your car is fully charged @ 2pm. And you keep it parked like that for an hour? A day?

murphyS90D | June 8, 2016

An hour - not a problem,
A day - not a good idea.
Unless you are getting ready for a trip where you need maximum range, don't charge more than 90%.

ram1901 | June 8, 2016

80% for daily use. plug it in every time I get home. let the battery management system do the rest. Walk away..
At 80% I can reach any Supercharger in the region with at least 20% remaining.

No need to overthink this process.

By developing the habit of plugging in every time you get home you'll never be without enough juice to get you to your next destination.
(It does NOT have anything to do with Tesla trying to wear out your battery early... as someone suggested above.)

tonyreyes2045 | May 1, 2019

Charging behavior can make quite a big difference in long term life, but it appears that even "bad" charging behavior results in long battery life:

Miles to 85% degradation based on charging behavior Range 310 miles
https://cleantechnica.com/2018/08/26/the-secret-life-of-an-ev-battery/
https://batteryuniversity.com/learn/article/how_to_prolong_lithium_based...
https://www.researchgate.net/publication/303890624_Modeling_of_Lithium-I...
Charging Parameters Cycles to capacity 85% Mi. per cycle Mi. to 85% degradation
100% — 25% 2,010 232.5 467,325
100% — 40% 2,800 186 520,800
100% — 50% 2,800 155 434,000
85% — 25% 4,500 186 837,000
75% — 25% 7,100 155 1,100,500
75% — 45% 10,000 93 930,000
75% — 65% 12,000 31 372,000

Boonedocks | May 1, 2019

I have ordered a SP100D +L and put my car on the "For Sale" section on TMC. Got a buyer shortly after it was put up.

The buyer asked me about my 100% and though some might find it interest.

Current mileage 73,447
2 years 3 months old
Daily charge to 90%
Usually arrive home with ~50%
RARELY charged to 100%
Never went under 20%
RARELY Supercharged

At 100% it was at 322 miles
335(original miles) -322(miles after 74k miles & 2.4 years) = 13 miles lost since new

That's a 3.9% drop after 2+ years

Also I have never re-balanced the batteries and some suggest some miles can be recovered by doing this but \i/