Best Way to Charge

[Whoster69]

If anyone has some good sources of information on the best way to charge please share them. Here are my particulars and I would like to get advice with explanations so I can understand it.

We drive about 35 miles a day round trip, M - F. We are getting a long-range model 3 with AWD. We are setting up a Nema 14-50 to charge with at home on a 50 amp breaker. Would we be better off charging every few days, topping off every day, or keeping it between certain percentages (like not letting it go below 205 or above 80% unless we are going on a long trip)?

Thanks.

 

[Big Earl]

Be prepared for a wide variety of answers to your question.

In general, keep it below 90% but make sure you keep enough charge in the battery to take an unexpected drive ... make sure you have enough to make it to a Supercharger outside of your immediate area (think evacuation scenario).

Beyond that, do whatever makes you happy.

 

[puckpurnell]

First up, get a 60 amp breaker! You'll charge at 32 amps but you need the 60 amp breaker. Charge rate will be about 28-29 mph. Very satisfactory.

I sent my charging limit to the first hash line or about 50%. Like you, I have minimal driving. I usually charge when I drop to about 80-90 miles on the screen. The energy use graph is a more accurate measure of the energy you have but when not worrying about long distance, I just use the screen number. Takes 2-3 hours to charge again to 150-155. After a while, you'll have your pattern figured out. Good luck.

 

[destructure00]

First up, get a 60 amp breaker! You'll charge at 32 amps but you need the 60 amp breaker. Charge rate will be about 28-29 mph. Very satisfactory.

A 50 amp breaker is sufficient to charge at 32 amps. I think a 60 amp breaker on a 50 amp outlet would be a code violation as well.

 

[Whoster69]

Be prepared for a wide variety of answers to your question.

In general, keep it below 90% but make sure you keep enough charge in the battery to take an unexpected drive ... make sure you have enough to make it to a Supercharger outside of your immediate area (think evacuation scenario).

Beyond that, do whatever makes you happy.

Thanks. I figured I would. I'm hoping that this will help me better understand good charging habits so I can become more knowledgeable.

Thanks to all who reply!

 

[destructure00]

There's a ton of threads here on TMC and if you google it on best target charge %. I've been searching a bunch and the general consensus I've seen is this:

Conceptually, the closer you can stay to 50% average the better off your battery will be. In practice, there is a negligible difference between any target charge level 90% or less.

So...if you want to be obsessive about it, find out how much capacity you eat up on a normal commute. For me, it seems like it's going to be about 10% each way, or 20% for a round trip. I would then target 60% charge, knowing that I'd be at 40% when I got home, and my average would be 50%.

If you want to set it and forget it, just choose 90% for daily and only use 100% when you are going to road trip somewhere and need the max range. When you do go to 100%, schedule the start time so that the car will hit 100% just before you leave rather than sit at 100% for a length of time.

Either way, you likely won't notice much if any difference in long term battery health or degradation.

Oh, and a plugged-in Tesla is a happy Tesla. No need to skip days.

This is all from reading and searching, not from personal experience...just got my car yesterday. I think I'm going to set my target to 80% (seems like a happy compromise??) and forget it unless I need extra range for something. Will charge every night.

 

[TexasEV]

First up, get a 60 amp breaker! You'll charge at 32 amps but you need the 60 amp breaker. Charge rate will be about 28-29 mph. Very satisfactory.

I sent my charging limit to the first hash line or about 50%. Like you, I have minimal driving. I usually charge when I drop to about 80-90 miles on the screen. The energy use graph is a more accurate measure of the energy you have but when not worrying about long distance, I just use the screen number. Takes 2-3 hours to charge again to 150-155. After a while, you'll have your pattern figured out. Good luck.

No to both. Probably best to set this user to “ignore”.

 

[Whoster69]

There's a ton of threads here on TMC and if you google it on best target charge %. I've been searching a bunch and the general consensus I've seen is this:

Conceptually, the closer you can stay to 50% average the better off your battery will be. In practice, there is a negligible difference between any target charge level 90% or less.

So...if you want to be obsessive about it, find out how much capacity you eat up on a normal commute. For me, it seems like it's going to be about 10% each way, or 20% for a round trip. I would then target 60% charge, knowing that I'd be at 40% when I got home, and my average would be 50%.

If you want to set it and forget it, just choose 90% for daily and only use 100% when you are going to road trip somewhere and need the max range. When you do go to 100%, schedule the start time so that the car will hit 100% just before you leave rather than sit at 100% for a length of time.

Either way, you likely won't notice much if any difference in long term battery health or degradation.

Oh, and a plugged-in Tesla is a happy Tesla. No need to skip days.

This is all from reading and searching, not from personal experience...just got my car yesterday. I think I'm going to set my target to 80% (seems like a happy compromise??) and forget it unless I need extra range for something. Will charge every night.

That confirms what I have read elsewhere. Thanks for stating it so concisely!

 

[LCR1]

First up, get a 60 amp breaker! You'll charge at 32 amps but you need the 60 amp breaker. Charge rate will be about 28-29 mph. Very satisfactory.

I sent my charging limit to the first hash line or about 50%. Like you, I have minimal driving. I usually charge when I drop to about 80-90 miles on the screen. The energy use graph is a more accurate measure of the energy you have but when not worrying about long distance, I just use the screen number. Takes 2-3 hours to charge again to 150-155. After a while, you'll have your pattern figured out. Good luck.

You only need a 40amp breaker to charge at 32amps, 50amp breaker for 40amp charging, and 60 amp breaker for 48amp charging.

 

[Petrlol]

I have LR AWD and drive about 15mi a day M-F, and maybe 100-200 on weekends.

I plug in to 14-50 whenever at home and have the limit at roughly 78%. If I know I have a trip planned the next day I set it higher and schedule it to start where I think it will finish charging to 96 or 97% when I leave.

6 months and 6k miles and it will still charge to 310 if needed.

 

[Petrlol]

As for the breaker discussion... Just get the 50amp that matches the outlet and 6awg wire.

You'll charge at a max of 32amp with the included charger on a LR AWD.

 

[ewoodrick]

There's not much real guidance as to the "best" way to charge. There are a few best practices that float around, but even these best practices are often debunked.

Just a couple of points...

• These batteries don't learn, so no need to take from full to empty.
• Taking to 0 isn't recommended as something that you should do every day, but if you have to, do it, just do it.
• Charging to 100% isn't something that you should do every day, but it is recommend and okay to do it for a long trip or when you need to do it. Just don't leave sitting at 100% for a long time (days)
• Every few months, it's probably good to bring to 100% to allow the batteries to balance.
• Lots of folks set max to 80%, but this it too low to let batteries equalize, 90% may be better, but as long as you do it periodically...
• The manual says that a plugged in car is a happy car (people take this a little too far though)

Probably the most important is that Tesla has designed the battery to be worry free and last a long time. They didn't design it for you to worry about it. They didn't design it for you to only use part of it. They designed it for you to drive the car, enjoy the car and have a lot of fun.

Charge at home or work, set your top limit to 80-90%. Don't worry about plugging in nightly, but you can if you want.

On the other hand, there are Tesla that have Supercharged every day for 500,000 miles, essentially on a single battery (early batteries were switched out) So, that break all the rules that people will give you.

 

[Goodtohave]

No to both. Probably best to set this user to “ignore”.

LOL my thoughts exactly...

I use my 40 amp breaker, unit set to 32 amps with 6 guage wire. Same wiring as I had for my J1772 from my Leaf.

 

[ArcticStation]

I worried about this for a month or two. Now, I just plug in at home at the end of the day, charge to 80%, repeat. Leave it plugged in after charge complete. If I think about it and feel that I might need it, I'll charge to 90% or 100% just before a trip. I almost never go below 20% on trips (our comfort zone, not because of battery health). Don't overthink it, you''ll find what works best for you after a few weeks.

 

[animorph]

This post has some good links:
Jeff Dahn's recommendation on long term battery preservation

I'm not sure if it's in one of those links, but generally many small charges cause less degradation than an equivalent long charge. So keep it plugged in.

 

[dhrivnak]

If anyone has some good sources of information on the best way to charge please share them. Here are my particulars and I would like to get advice with explanations so I can understand it.

We drive about 35 miles a day round trip, M - F. We are getting a long-range model 3 with AWD. We are setting up a Nema 14-50 to charge with at home on a 50 amp breaker. Would we be better off charging every few days, topping off every day, or keeping it between certain percentages (like not letting it go below 205 or above 80% unless we are going on a long trip)?

Thanks.

For a NEMA 14-50 you should use a 50 amp breaker, that is what is expected and that is the code. Per Tesla's recommendation plug it in every day and I would set the standard charge to 80 or 90%. 100% should only be used when necessary. Below 80% you risk getting the batteries unbalanced with time.

 

[Whoster69]

This post has some good links:
Jeff Dahn's recommendation on long term battery preservation

I'm not sure if it's in one of those links, but generally many small charges cause less degradation than an equivalent long charge. So keep it plugged in.

Thanks. I'll check'em out.

 

[Big Earl]

For a NEMA 14-50 you should use a 50 amp breaker, that is what is expected and that is the code. Per Tesla's recommendation plug it in every day and I would set the standard charge to 80 or 90%. 100% should only be used when necessary. Below 80% you risk getting the batteries unbalanced with time.

A 40 amp breaker is also acceptable and perhaps more appropriate for a gen 2 mobile connector.

 

[Daniel in SD]

A 40 amp breaker is also acceptable and perhaps more appropriate for a gen 2 mobile connector.

"Acceptable" but not to code.

 

[Big Earl]

"Acceptable" but not to code.

Show me where code prohibits a 40 amp breaker on a NEMA 14-50 receptacle.

In Canada, code requires 40 amp breaker... 50 is too high.