What should my ideal charge percentage be?

[Tedkidd]

This is what I'm hoping for after the 6.0 update of the nav system. I can tell the car "tomorrow is the usual" or "tomorrow I'll drive to xyz" and it picks the best charge rate...

OK, I guess this will be in the 8.7 firmware update

Connecting to google calendar to see where you are going tomorrow? That'd be cool!

 

[EchoDelta]

Connecting to google calendar to see where you are going tomorrow? That'd be cool!

Unless it forces you into obsessively putting all physical locations into appointments. I keep my calendar updated ; but a lot of location names are not machine readable or apply to members elsewhere . I don't want to get range charge every day I have calls with NYC (just exaggerating)

 

[EchoDelta]

The slider is the way around it.

Yeah so you remove the "inferred" setting and just make the slider green where you're there, or put a marker on the slider. Whatever, there's a dozen design options around not having an extra setting and nudging people into behaviors

 

[TexasEV]

Remember the goal is to keep it simple. Tesla has to expand beyond early adopters and enthusiasts. Most people just want to get in the car and drive somewhere. They shouldn't have to think about changing charging level from one day to the next, planning how far they're driving the next day, or even to set it to some "ideal" level. They just need to have the slider set to the max range that doesn't kill the battery and be told to change it to 100% for road trips.

 

[dirkhh]

Unless it forces you into obsessively putting all physical locations into appointments. I keep my calendar updated ; but a lot of location names are not machine readable or apply to members elsewhere . I don't want to get range charge every day I have calls with NYC (just exaggerating)

It simply learns. Just like Google Now. It's scary how well Google knows when I need to be where.
But I guess the KISS principle overrides all these exciting ideas.

 

[Tedkidd]

It simply learns. Just like Google Now. It's scary how well Google knows when I need to be where.

Never going back to iPhone...

 

[preilly44]

So is 80-90% still the recommended charging point?

Patrick

 

[David99]

So is 80-90% still the recommended charging point?

The slider goes down to 50% for a good reason. If you only drive 40 miles a day, it's good for the battery to set it to 50%. The lower state of charge helps overall battery life. The idea is to set it to a level that easily covers your daily need but not more. There isn't one best level, it really depends on how much you drive. I often adjust mine differently for the next day.

The tow main factors are: the lower the state of charge, the better for the battery life. The higher the state of charge the less likely you are going to run out of battery if something happens. Finding the right balance of these two opposing factors is up to you

 

[Klaus]

There have been quite lengthy discussions in other threads strongly suggesting that charging to less than 90% regularly will (apparently temporarily) decrease the maximum available range. This may be due to lack of pack balancing, the system slowly losing track of the total range of the pack and maybe other reasons. Charging at 90% for a few weeks will recover most of that loss, and deeper discharges seem to help that process.

Personally, I have had exactly that experience after I charged only to 80% for a few months. Since I drive a 60, not losing 10 miles or so of my maximum range when I need it occasionally short term has become more important than maximizing long term battery life, which for most MS owners is mostly theoretical at this point (exceptions have been reported).

 

[Senox]

So what is the summary? Should I keep the SOC below 75% if I don't need the range or should I charge to 90% to prevent unbalanced batteries?

Normally I don't drive more then 10-20 miles per day and are able to charge both at work and at home. Should I have the charger plugged in always or should I charge it to 90% mabey once a week to have the SOC closer to 50% but still charge it so the batteries get balanced.

Thankfull for for some Advice!

 

[jerry33]

So what is the summary? Should I keep the SOC below 75% if I don't need the range or should I charge to 90% to prevent unbalanced batteries?

Normally I don't drive more then 10-20 miles per day and are able to charge both at work and at home. Should I have the charger plugged in always or should I charge it to 90% mabey once a week to have the SOC closer to 50% but still charge it so the batteries get balanced.

Thankfull for for some Advice!

1. Don't bother charging at work.

2. From Sunday night/Monday morning to Thursday night/Friday morning charge to about 120-130 rated miles. For the weekend do a full daily charge so that you can do longer outings.

3. Set the timer so that the charging ends at about the time you leave.

 

[Senox]

Thanks Jerry!

 

[Kilowatt]

Wouldn't it be a great feature to be able to plan charge rates using a weekly schedule? More on weekends, less on weekdays. And adding to that - (optional) automatic higher charge if calendar suggests longer road trips?

 

[scaesare]

Wouldn't it be a great feature to be able to plan charge rates using a weekly schedule? More on weekends, less on weekdays. And adding to that - (optional) automatic higher charge if calendar suggests longer road trips?

I do this today with Visible Tesla.

(unfortunately the new Tesla servers have given some folks log-in troubles... so far that hasn't bitten me yet).

 

[mknox]

I have heard it is best to run the battery in the middle of it's range. Last summer, I would charge to 70% and end my day at about 30 to 40%. The only caveat here is that the battery may get out of balance due to infrequent full charges. I discovered this when I went to do a Range Charge and found my Rated Miles had dropped quite a bit from what they were before I started doing the 70 to 30 cycles.

 

[Merrill]

I hardly ever do a range charge, maybe 5 times in over 1-1/2 years, I know this has been discussed before but does it hurt the battery to intermittently do a range charge. I was thinking maybe once a month, how does this effect the pack balancing.

 

[jerry33]

I hardly ever do a range charge, maybe 5 times in over 1-1/2 years, I know this has been discussed before but does it hurt the battery to intermittently do a range charge. I was thinking maybe once a month, how does this effect the pack balancing.

As far as I'm aware, it's leaving it at a very high or very low SOC, especially during hot weather, is what degrades the battery quickest. Driving shortly after a full range charge isn't particularly harmful. The absolute best routine would be to charge to 60%, drive to 50% and repeat--of course that's not practical but it would result in battery life being based on time rather than charging cycles.

Pack balancing is a subject of much speculation, few facts, and no official statements. What's known from disassembling the battery is that the pack balancing occurs very slowly. It's also known that the algorithm used for rated miles is changed frequently, so ideal miles might be a better measure than rated miles, maybe. There's several threads on balancing and you can form your own opinions.

I range charge if I need to, and otherwise just charge inside the daily range.

 

[kirkbauer]

I have a P85D being manufactured now. For better or for worse my daily commute is about 8 miles round-trip, but I do plan to take advantage of the acceleration when I can.

From what I can tell the recommendation would be to charge every day to say 55%? Would there be any benefit to charging to say 75% on Sunday night and not plugging in during the week? Or would that affect the range due to leaving a higher charge in there?

And my bigger question: I have read that the acceleration of the P85D is affected by battery charge level? Is that true? I can't find any details on exactly how it is affected.

 

[TexasEV]

From what I can tell the recommendation would be to charge every day to say 55%? Would there be any benefit to charging to say 75% on Sunday night and not plugging in during the week?

No, no, no. When you read the owners manual you will see Tesla recommends keeping the car plugged in whenever you can. It can't overcharge. Remember "A connected Model S is a happy Model S."

Anyway don't overthink this. Set the charge level at what you're comfortable with if you have to make an unanticipated trip, and let the battery management system manage the battery. There hasn't been shown to be a material impact on the battery no matter what state of charge you keep from 50-90%, just don't charge to 100% routinely and leave it there. Otherwise just enjoy the car and don't think about the battery.

 

[Gear]

I have a P85D being manufactured now. For better or for worse my daily commute is about 8 miles round-trip, but I do plan to take advantage of the acceleration when I can.

From what I can tell the recommendation would be to charge every day to say 55%? Would there be any benefit to charging to say 75% on Sunday night and not plugging in during the week? Or would that affect the range due to leaving a higher charge in there?

And my bigger question: I have read that the acceleration of the P85D is affected by battery charge level? Is that true? I can't find any details on exactly how it is affected.

What TexasEV said. To answer your last question, batteries are capable of discharging at a higher rate when they have more charge, so at a full charge it will accelerate the quickest. You probably won't notice much difference, though, until you get to a very low state of charge (<10%).