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How charging frequency affects battery health

How charging frequency affects battery health

Hi, My work is 22 miles away from home. I have 220V chargers at both locations. Is it better for the battery to charge once a day to replenish about 50 miles of range (20%), or to divide the charging on both locations? I usually charge the battery to around 75% - 80%.

jimglas | 07. januar 2020

A plugged in Tesla is a happy tesla. Keep it on the charger when not in use.

Lonestar10_1999 | 07. januar 2020

If you can charge for free at work then only charge at work.

Pg3ibew | 07. januar 2020

I can chatge at home and at work. I charge at work ALL the time. I only vharge at home whem I have to. BUT....I am always plugged in at home.

bucfan11 | 07. januar 2020

I have the same question as a new owner. My wife will sometimes only put 25 miles a day on the car. So I really need to plug it in every night? I don't mind plugging it in but I dont mind running it down to 50% or so either. Which is actually better for the battery?

FISHEV | 07. januar 2020

Don't see anything from experts on that question. I suspect it doesn't matter as long as you are not charging more than 80%.

https://batteryuniversity.com/learn/article/charging_lithium_ion_batteries

jimglas | 07. januar 2020

EM says charge to 90%

Joe M | 07. januar 2020

There are a number of lower mileage users who would be very interested in the answer to many small charge sessions say 10-15 kw vs. fewer larger ones like 30-50 kw. Ultimately I am pretty sure the battery won’t be the failure point in a car that’s only driven 15k miles a year but it would be nice to know what method promotes the best battery health. There is also the question of efficiency in preparing the battery in colder climates per session many small or fewer large. Way past my knowledge base but curious.

vmulla | 07. januar 2020

For about 8months I was charging at a worksite, but that was limited to 1hr duration (honor system). So I was charging both at work and at home. Always plugged in at home to a charge limit of 90%. 2yrs and 50K miles later my battery is doing A-Ok. Just one data point.
I think your battery is going to be fine based on my experience.

TexasBob | 07. januar 2020

If only there was an owners manual that came with the car that could answer this (often asked) question. Oh wait. Page 145

"Model 3 has one of the most sophisticated battery systems in the world. The most important way to preserve the Battery is to LEAVE YOUR VEHICLE PLUGGED IN when you are not using it." (emphasis in the original)

"There is no advantage to waiting until the Battery’s level is low before charging. In fact, the Battery performs best when charged regularly."

https://www.tesla.com/sites/default/files/model_3_owners_manual_north_am...

gballant4570 | 07. januar 2020

When you are not driving it, plug it in. Set your charging limit to your choice and plug it in.

kevin_rf | 07. januar 2020

I thought he said charge to 110%

Joe M | 07. januar 2020

@TexasBob

I appreciate and am aware that is in the manual but I am pretty sure that the manuals recommendation is a compromise say to make sure folks don’t forget to plug it In or any other number of scenarios. Tesla certainly doesn’t want owners to experience the dreaded 0% because they forget to plug it in. I have alternate reasons in a stored vehicle to mess with the charge percentage to charge more and less frequently say once every two weeks vs. a trickle a day so the real technical answer if it exists is of interest.

abhassan | 07. januar 2020

Thanks for all the replies. Even the smart ass ones.
Cheers

gballant4570 | 07. januar 2020

Joe M, if you know better than the manual, why read it?

Joe M | 07. januar 2020

Tough crowd. I want to deviate for good reason and I want the data if available for that deviation.

vmulla | 07. januar 2020

@Joe M,
The car will tell you if you're doing something bad. Pay attention to those notifications from the car, you should be OK. Except for paying attention to those messages, I didn't pay particular attention to maintaining my battery.

Joe M | 07. januar 2020

TY

Curious on the messages, do you know if it will it tell me on the app, on the car screen, or via email? I am away from it.

andy.connor.e | 07. januar 2020

+1 @Lonestar

If charging at work is free, charge at work.

EAPme | 07. januar 2020

@TexasBob. Amen.

OP: Got it. FU to RTFM. Ignore the manufacturer's guidance on the use of the car, sounds like a wonderful plan.

Joe M | 07. januar 2020

@EAPme

Not for nothing but I am pretty sure your nasty is directed to me not the OP.

jfaubl | 07. januar 2020

For some reason I can't post a link. On the battery university site look for how to prolong battery life.

Short charges are better. Charge at both locations. I have a 4 mile commute and use to wait days to charge. Now I plug in every night.

EAPme | 07. januar 2020

@Joe M

Very noble of you, yes (sorry OP). Not being nasty, just perplexed why someone would willfully ignore what's in the manual. If you've been following some of the recent battery threads on this forum, you'll see lots of folks react viscerally to some of the questions/statements that are made about battery health.

Point I'm trying to make? The manual that Tesla's provided us represents an excellent resource - to dismiss it isn't helpful to folks who are reading these threads.

Joe M | 07. januar 2020

@jfaubl

Wow someone who actually answers my question with real data! Thanks so much. I leave mine plugged in all the time in storage but was adjusting the charge point via the app for long cycles to provide extended cold periods to avoid sending out a “here is a warm place” signal to mice. I will have to decide between risks I guess. Thanks.

vmulla | 07. januar 2020

Joe M | January 7, 2020
TY

Curious on the messages, do you know if it will it tell me on the app, on the car screen, or via email? I am away from it.
----
The messages show up on the car's screen and the app. No email.
The messages that I saw and recollect are:
- warnings for repeated Supercharging to 100%
- warnings to charge battery when soc is very low

The color coding of the battery icon helps too. Avoid amber and red battery icons - simple.

Joe M | 07. januar 2020

@vmulla

TY

jfulton67 | 07. januar 2020

Today I celebrate 1 year with my Model 3. No regrets and honestly, with all the updates, it's a different car than as year ago. I charged 100% because I was getting like I've just total charge. Probably only tht 5th time all year. 100% charge was 250 miles. With the 4 Mike upgrade, that's a14 mile lost. Did that seen normal? Just checking

Tronguy | 07. januar 2020

FISHEV is present. Public Service Announcement:

FISHEV is a known troll of several years standing and several user
names who pushes an anti Tesla narrative. Please
take his opinions with a grain of salt, avoid any advice he may
suggest, and do not let him implant any Fear, Uncertainty, or Doubt
about Tesla or your car into your own opinion.

ellett | 11. januar 2020

Generally, leave it plugged in, but if you notice the range dropping significantly, drive it down to 20% or so and then charge back to 90% so the battery management circuitry will reset and give you the correct figures.

gmr6415 | 12. januar 2020

@vmulla, you mean like the one you get on the touchscreen at about 4% stating something like if you don't charge immediately you may cause permanent damage to the battery? Not those exact words.

I've gotten that one a few times and you can tell they're really trying to knock that one home.

syclone | 12. januar 2020

Based on all the "expert" advice that I've been reading for the last 18 months since I've owned my car (LR-RWD-EAP) I have to charge my car to 68.5% on Alternate Tuesdays and Saturdays. But only in months that have an R in them. In other months, any day is OK.

People, drive the car and enjoy it. The battery will last longer than 95% of you will own the car.

kevin_rf | 12. januar 2020

My Prius will be 16 this year, it's still on the road being used daily to take the kiddo to college.

I buy cars for the long haul and drive the wheels off them. Anything less than 10 years with the Model 3 will be disappointing.

vmulla | 12. januar 2020

@gmr6415,
Yes, those are the kinds of messages I'm talking about.

jordanrichard | 12. januar 2020

This isn’t complicated. Leave the car plugged in whenever possible, don’t set the SOC higher than 90% and don’t routinely let the car get below 10%.

I have been doing this on my MS85 since March 2014, presently have 175,000 miles and only 5% range loss.

When I first got my car I did once try to see how many days I could go without charging and I got to 4 days but I then realized that wasn’t a good idea. If I had to make an unexpected trip out of state, having my car sitting at 50 miles not eh battery, wouldn’t be a good thing. So I stopped that practice.

vmulla | 12. januar 2020

@jordanrichard said it nicely.

FISHEV | 12. januar 2020

"The battery will last longer than 95% of you will own the car."

It's more useful life and range that is the key. My average Wh/mile is 272 which gives me range of 275 at 100% charge. Charging to 85%, not discharging below 10% to slow battery degradation means that i have an effective range of 206 miles for a 310 rated car. Add in Winter deration of 20% and that's 160 miles usable range.

For some people, that can mean the difference between the car working for them or not.

To this question of frequent charging, there's no evidence that hurts the battery. Charging above 85% and discharging below 10% will increase battery degradation. Frequent small charges won't hurt. Frequent small discharges are best for battery health vs. fewer larger discharges is they way I read the www.batteryuniversity.com information.

AstroSteve | 12. januar 2020

Our Tesla Service Center hosts Owner's Boot Camps with the Delaware Valley Tesla Owners club.
They advised routine charging to 90% and ABC - Always Be Charging.
Advice seems to match up with the best I've heard here and elsewhere.
ABC - remember it, live it.

FISHEV | 12. januar 2020

"Always Be Charging."

Kind of idiot light approach. Like people saying "Just drive the car" vs. understanding how it works and why.

Why should we "always be charging" is the real question. No reason to as the real key is don't charge to full, don't discharge below 10%. Small discharges with small recharges is what you are aiming for to slow battery degradation. "Just leave it plugged" in is the "Charging for Dummies" answer.

On the 90%, kind of a Musk thing vs. a www.batteryuniversity.com thing. As others have pointed out, Tesla has a margin built in, we saw some of it get used when same car was rated 310 miles one minute and 322 the next with no changes to the car. 90% of 310 is 85% of 322.

sheldon.mike1010 | 12. januar 2020

Most Fish are mouth breathers

jfaubl | 12. januar 2020

One thing the service tech told me when he was installing my spoiler is, people get all worked up about how often to charge the battery, but no one thinks how many times a day you engage regenerative braking which does 100 to 1000 small micro charges a day to your battery.

FISHEV | 12. januar 2020

"no one thinks how many times a day you engage regenerative braking which does 100 to 1000 small micro charges a day to your battery."

Good point.

pcrz | 12. januar 2020

FISHEV is present. Public Service Announcement:

FISHEV is a known troll of several years standing and several user
names who pushes an anti Tesla narrative. Please
take his opinions with a grain of salt, avoid any advice he may
suggest, and do not let him implant any Fear, Uncertainty, or Doubt
about Tesla or your car into your own opinion.

vmulla | 12. januar 2020

Always charging approach is good.

51752 miles on my car as of posting this message. I've been following this 'always charging' approach over the life of the car (almost 2yrs). Effect? Zero loss in estimated range since I bought my car.

FISHEV | 12. januar 2020

Bottom line, it is the volume of the charge that causes the most degradation not the frequency of the charges.

vmulla | 12. januar 2020

Did I mention that I charged to 100% dozens of times and depleted the battery to single digits immediately after charging to 100%? Oh, and I did that on Superchargers too. Over 180 Supercharger visits too..

And still... Zero loss in estimated range since I bought my car. Want screenshots, videos, or data to prove it all? Just ask, I'd be too happy to oblige :))
---

The real bottom line is that Tesla engineers wrote software to make battery management idiot proof. They're doing incredible battery management for you so that you can enjoy the car.

FISHEV | 12. januar 2020

"Zero loss in estimated range"

After 52,000 miles and two years. Should be calling the Smithsonian so we can get this outlier Li-on battery into the history books.

For more within the norms of Li-on tech we should see battery degradation from day one, up to 10% first year would be "within normal limits", anything less than 30% over eight years would be within the norms.

FISHEV | 12. januar 2020

Here's a graph of all LR AWD owners and the spread of battery degradation.

https://imgur.com/Ka0SdZU

andy.connor.e | 12. januar 2020

the fish has been flagged!

vmulla | 12. januar 2020

:))
I knew I'd be called out for being an outlier. But here's the thing , the battery compare app says that I'm doing better than 79% of the Model 3s out there. The battery is doing better than most. Bit it's hardly an outlier.

Here's the screenshot
https://photos.app.goo.gl/okaX92MxTUGZj8SU6

The real story is that I did just normal battery management - I did NOT do anything special, and yet the battery is going strong.