100% Battery Charge

[aesculus]

My 90% has recently descended down to 233 miles from 237 so I thought I would give a 100% charge a try. My car has 2400 miles on it. Last night I came into a supercharger at 8% and thought why not? I had another 75 miles left to burn off so I thought it would be a good time. At first the timer said 1 hour and 10 minutes which I thought was good. I was the only one at the supercharger. After a few minutes it ascended to 120 minutes but still I thought OK.

Well after about 1 hour 10 minutes I was around 90% which was about normal. Seemed to be at 238 so maybe I picked up a mile. I kept going. At around 1 hour 30 I was at 257 which is what the 90D is rated at 100%, but I am still not fully charged. I kept plugging away but now the amps are in the single digits. For another 1/2 hour I waited for it to get to 100% and stop charging but it never did. The amps decreased to 2, but at that rate it could have been at least another 30 minutes, if ever, before it got to 0 amps and 100%. I unplugged and drove off with the battery showing 259 RM. I also reset the charge back to 90%.

When I got home, after burning off about 75 miles, I plugged in and since it was late the charger got right to it (I have the car set to charge at 11 pm). The next morning I got an alert that the car was fully charged to 234. So I was back to the same 90% state before I did the full charge.

So three questions:

1. Would the car ever reach 100% charge at a supercharger or at a HPWC?
2. Should the 90% RM have gone back up to 237?
3. What is the correct procedure to get the RM back at 90% or did I really do that when I got it to 259 RM and my 90% at 237 was just some fictitious number during during the first 1500 miles?

1. 

 

[TexasEV]

1. Yes it will but you don't want to wait that long.
2. No.
3. There is no procedure. You're making too much of these exact numbers. They're estimates based on algorithms based on the battery's estimated state of charge which can't be measured directly. If two or three miles would make a difference for you, you're cutting your trip planning way too close.

My advice is to chill out and just enjoy the car. Let the battery management system manage the battery.

 

[porsche1662]

Do you have the P90D or the 90D ? I get 260 at 90% with my 2016 90D

 

[swesson]

Do you have the P90D or the 90D ? I get 260 at 90% with my 2016 90D

Welch me to the forum! You do realize this is a Model X forum section, right? Likely, you have an S.

 

[porsche1662]

Welch me to the forum! You do realize this is a Model X forum section, right? Likely, you have an S.

Oh shoot !! Sorry, Ill get out.

 

[aesculus]

Do you have the P90D or the 90D ? I get 260 at 90% with my 2016 90D

Welch me to the forum! You do realize this is a Model X forum section, right? Likely, you have an S.

Oh shoot !! Sorry, Ill get out.

I am sure it was just a passive aggressive maneuver to make us Model X owners feel range inadequate.

 

[Aljohn]

It seems to charge at an ever decreasing limit -- that is as the battery fills, the resistance of the battery increases so the current diminishes and an ever decreasing rate (from 300amps to a mere 2 amps). With an ICE, we tend to think of filling up. I learned on my first Model X long distance journey, that when the X said "you have enough power to proceed to the next super charger or destination" Drive ON! An additional 10% will take longer than the time it takes to re-charge to 50-70% at another Super Charger. Think of this like trying to fill a bucket to the very top and not spill a drop -- you can fill the bucket rapidly when it is less that half full, then you would fill less and less and less as it nears the top. Not exactly the way electronics work, but makes the point. Getting the last ounce of water in the 5 gallon bucket will take longer that the first 4 gallons.

Let the Trip Planner and battery management system do its job. The recommendation is to charge for your daily needs, and only charge 100% for the beginning of a trip.

 

[xkwizit]

I had the same question when I bought my Model S. TM explained to me that when the car is new it will show you the full rated miles. As the car learns your driving habits such as how fast you drive, how fast you start from a complete stop etc. the car recalculates how much you will actually get out of a charge 90%, 100% whatever you charge it to.

 

[porsche1662]

I am sure it was just a passive aggressive maneuver to make us Model X owners feel range inadequate.

No Im just surprised the same battery is 35 miles less. Im in Ohio and the X is just hitting our stores so I know very little about the differences as of now. So far only have noticed 1 on the road and one in the service center. Even at 100% charge on the S being 294 miles in real life its really only 250 miles and then too nervous to go below 50 miles so really 200 miles ?? hoping that they keep increasing the range at a steady pace. One other tip since I owe you guys for going to the wrong party. I had the roof tinted with 50% ceramic. They applied it right over the existing tint and it looks awesome. Cut out all of the heat. It was either that of get the ugly sun shades that my wife wanted me to get. I can only imagine the X roof heat so not sure its the same issue.

 

[deonb]

I had the same question when I bought my Model S. TM explained to me that when the car is new it will show you the full rated miles. As the car learns your driving habits such as how fast you drive, how fast you start from a complete stop etc. the car recalculates how much you will actually get out of a charge 90%, 100% whatever you charge it to.

That is so not true. TM DS's have been saying that since 2012, but there has never been any evidence of this.

If the car compensated for driving habits, most of us will have their 90%'s in the 160 to 200 range.

Or at the very least the number will change when 2 different people drive the car for extended periods. It doesn't.

 

[TexasEV]

I had the same question when I bought my Model S. TM explained to me that when the car is new it will show you the full rated miles. As the car learns your driving habits such as how fast you drive, how fast you start from a complete stop etc. the car recalculates how much you will actually get out of a charge 90%, 100% whatever you charge it to.

As denob said, this is wrong. The rated miles display is exactly that-- EPA rated miles.

 

[ecarfan]

It seems to charge at an ever decreasing limit -- that is as the battery fills, the resistance of the battery increases so the current diminishes

This is nothing new. It is true of all EVs, and has been true for every car Tesla has made. And Tesla specifically states that is the case at Supercharger | Tesla Motors
Look at the "Supercharger Charging Profile" graph on the right side of that page, partway down.

 

[MattXowner]

Silly question...as you can see from my log I added 20.21 kWh to my X earlier this week. Do I just take that number and multiply it by my kWh rate to see what it costs?

So at 0.10 per kWh its $2.02 of electricity?

 

[eye.surgeon]

Rated miles does not have any bearing on the health or capacity of your battery. It is an algorithm based on a variety of driving and performance metrics and in no way is it accurate enough for you to make any judgement about the actual capacity of the battery or any change in capacity.

 

[TacC]

Silly question...as you can see from my log I added 20.21 kWh to my X earlier this week. Do I just take that number and multiply it by my kWh rate to see what it costs?

So at 0.10 per kWh its $2.02 of electricity?


View attachment 180398

Roughly speaking, yes. You added $2.02 of electricity to the car. You probably drew a lot more from the grid, though.

I believe Tesla has claimed 92% charging efficiency and your setup could be less efficient. So you're in for at least $2.20 on that charge. If you were using the battery warmer, climate control, etc. those items would draw power, as well.

 

[X Fan]

Roughly speaking, yes. You added $2.02 of electricity to the car. You probably drew a lot more from the grid, though.

I believe Tesla has claimed 92% charging efficiency and your setup could be less efficient. So you're in for at least $2.20 on that charge. If you were using the battery warmer, climate control, etc. those items would draw power, as well.

To validate: I get 94% at home (per TeslaFi)......