Page 363 of 369

range loss compared

Posted: Tue Apr 23, 2019 10:14 am
by jlv
My LEAF, when new, had 283 GIDs/22.0kWh available in LeafSpyPro. When I sold it at 4.5 years old and 34K miles, it had 249 GIDs/19.3kWh available. That's about a 12% loss (19.3/22.0) or a real world loss of about 11 miles (based upon 4.0 mi/kWh). It was still showing 12 bars.

(the GOM still gave some useless numbers like 98 or 105 or 110 miles range, but that's not because Nissan was trying to hide the real range from me)

My S 75D started at 257 miles range when brand new (charged to 100%). 2 years and 33K miles later, a 100% charge is now 249 miles. That 8 mile difference is somewhere under a 4% loss of rated range. IIRC, rated range is based upon 278 wh/mi (or 3.59 mi/kWh); it does seem about right, because the 75 has apparently 72.6kWh capacity available (257/72.6 = 3.53 mi/kWh). The rated range isn't a GOM - it's just math.

How close is the rated range to real driving? I can get as low as 240 wh/mi at 65 MPH on flat roads, but I almost never see that. Without heat, I usually see around 300-350 wh/mi on the highway. Here's a more typical drive -- a two hour segment between two SuperChargers at 70-75MPH:
Image

My S has about the same number of miles as the my LEAF but over half the time frame. Most of the miles on the S have been from long trips with SuperCharging, whereas in the LEAF most of the miles were commuting 21 mi/day and charging at work at 30A to 100%. This is not really an apples-to-apples comparison.

The S has some range loss, but I don't think it's on the same level as my LEAF.

Re: Official Tesla Model S thread

Posted: Tue Apr 23, 2019 11:16 am
by Valdemar
The point being without knowing how Tesla BMS works, and no one except Tesla engineers does, it is impossible to know how much capacity is actually lost in absolute terms. Range loss is not necessarily 1:1 to capacity loss, until the battery ages to a certain point anyway. That point was fairly early in the original Leaf battery life, but at Tesla capacities it's naturally pushed out further.

Re: Official Tesla Model S thread

Posted: Tue Apr 23, 2019 3:28 pm
by EVDRIVER
Valdemar wrote:The point being without knowing how Tesla BMS works, and no one except Tesla engineers does, it is impossible to know how much capacity is actually lost in absolute terms. Range loss is not necessarily 1:1 to capacity loss, until the battery ages to a certain point anyway. That point was fairly early in the original Leaf battery life, but at Tesla capacities it's naturally pushed out further.
Wrong, the full usable pack capacity is known on each model and people have the ability to see this on many cars and the losses over time. Tesla does not have a surplus of capacity they open up on uncorked cars. You don't need to know how a cars BMS works to see the cars capacity. Also the stated range on a Tesla is a fixed number when the car is fully charged so all variables being equal if it goes down the capacity is going down, it does not work on an estimate of driving habits, etc like a LEAF. Regardless, all the things that you say are not possible have been done years ago and are validated. Not sure what you mean by "how the BMS works" But plenty of people have access to the same info the engineers at Tesla have and you don't need to backward design the BMS to get what you need. LOL

Re: Official Tesla Model S thread

Posted: Tue Apr 23, 2019 3:33 pm
by Valdemar
EVDRIVER wrote:
Valdemar wrote:The point being without knowing how Tesla BMS works, and no one except Tesla engineers does, it is impossible to know how much capacity is actually lost in absolute terms. Range loss is not necessarily 1:1 to capacity loss, until the battery ages to a certain point anyway. That point was fairly early in the original Leaf battery life, but at Tesla capacities it's naturally pushed out further.
Wrong, the full usable pack capacity is known on each model and people have the ability to see this on many cars and the losses over time...
Reference, please. No disrespect, but if you're quoting yourself I have to take it with a grain of salt.

The full usable can be determined empirically by owners, the full actual or rather its estimate is only known to the BMS.

Li-Ion cells lose 3-5% capacity a year in storage. Jlv mentions less than 4% losses in 2 years with cycling. The rest of the losses happened in the inaccessible to user buffer and cannot be seen without using special diagnostics equipment, if there are other theories I'm all ears.

http://jes.ecsdl.org/content/163/9/A1872.full

Image

Re: Official Tesla Model S thread

Posted: Tue Apr 23, 2019 4:36 pm
by GRA
jlv wrote:Everyone said I was daft to get a Tesla. but I got one all the same, just to show them. I'm actually on my 4th S. My first sank into the swamp and then caught fire. So I got a second. That sank in the swamp and caught fire, too. The third caught fire first, and then I pushed it over into the swamp for insurance fraud. But the fourth one hasn't caught fire. That's the one my son will inherit, even though it has capacity loss that Elon has hid from me.
But you've left out the most important information - does your sons fiance' come with huuuuge (cups hands at chest height) . . . tracts of land?

Re: Official Tesla Model S thread

Posted: Tue Apr 23, 2019 4:45 pm
by EVDRIVER
Valdemar wrote:
EVDRIVER wrote:
Valdemar wrote:The point being without knowing how Tesla BMS works, and no one except Tesla engineers does, it is impossible to know how much capacity is actually lost in absolute terms. Range loss is not necessarily 1:1 to capacity loss, until the battery ages to a certain point anyway. That point was fairly early in the original Leaf battery life, but at Tesla capacities it's naturally pushed out further.
Wrong, the full usable pack capacity is known on each model and people have the ability to see this on many cars and the losses over time...
Reference, please. No disrespect, but if you're quoting yourself I have to take it with a grain of salt.

The full usable can be determined empirically by owners, the full actual or rather its estimate is only known to the BMS.

Li-Ion cells lose 3-5% capacity a year in storage. Jlv mentions less than 4% losses in 2 years with cycling. The rest of the losses happened in the inaccessible to user buffer and cannot be seen without using special diagnostics equipment, if there are other theories I'm all ears.

http://jes.ecsdl.org/content/163/9/A1872.full

Image

Plenty of people have hacked into the Tesla OS and can see more than even the service techs. I had access to data on my S in incredible detail. Your loss claims above are not even in line with my LEAF losses in a cold climate after a year and I had the dealer consult 2 software in 2011 Your claim that Tesla is buffering losses is nonsense, they don't need to do that. The big picture is the loss on Tesla cars is very low and crazy low compared to a LEAF pack of course and there is not cheating needed to do that.

Re: Official Tesla Model S thread

Posted: Tue Apr 23, 2019 4:53 pm
by Valdemar
Yeah, that's what I thought. My Leaf loses 6-8% annually, which is excessive from the owner's standpoint but I can see it being realistic given the typical Li-Ion calendar losses + cycling and lack of thermal management in a warm climate. 2% annual capacity loss for Tesla is below typical calendar losses. The numbers don't add up to support your theory. There must be a buffer and the BMS takes from it as battery loses capacity to maintain the impression your usable capacity reduces very slowly. Let's talk in 2021 when there is more data on well-aged out of warranty Tesla batteries. And it is not cheating, overall if batteries hold well after 8 years who cares if it is actually 6% per year and not 2% that we were led to believe as the car will still be usable for a while, but if they start to fail left and right due to deeper cycling it doesn't bode well for used Tesla resale values long term.

Re: Official Tesla Model S thread

Posted: Tue Apr 23, 2019 5:12 pm
by Evoforce
I find it amazing that people that don't have personal experience owning both a Leaf and a Tesla are trying to negate the experiences of those who do have first hand experience. There is denial or hatred of Tesla that currently is the better car.

Re: Official Tesla Model S thread

Posted: Tue Apr 23, 2019 5:32 pm
by Valdemar
For the record, I do not deny or hate Tesla. Unlike many Tesla car or stock owners I don't promote it as I have no personal agenda wrt its success or failure for that matter. As it is today it is an expensive toy that may prove to be fragile or to be a liability in the long run. If one is comfortable with the risks and has the resources then by all means it is the EV to get. I am patiently waiting until more data is available about long term ownership and Tesla is at lower risk of going belly up, I don't want to repeat the same mistake I made when I bought the Leaf, and I'm also very careful now when I'm listening to recommendations from those who made this same mistake. The data I see tells me the reported "low" battery capacity loss rate is not realistic unless backed by a capacity loss buffer, but I will be happy if I'm proven wrong.

Re: Official Tesla Model S thread

Posted: Tue Apr 23, 2019 6:58 pm
by Evoforce
Valdemar wrote:For the record, I do not deny or hate Tesla. Unlike many Tesla car or stock owners I don't promote it as I have no personal agenda wrt its success or failure for that matter. As it is today it is an expensive toy that may prove to be fragile or to be a liability in the long run. If one is comfortable with the risks and has the resources then by all means it is the EV to get. I am patiently waiting until more data is available about long term ownership and Tesla is at lower risk of going belly up, I don't want to repeat the same mistake I made when I bought the Leaf, and I'm also very careful now when I'm listening to recommendations from those who made this same mistake. The data I see tells me the reported "low" battery capacity loss rate is not realistic unless backed by a capacity loss buffer, but I will be happy if I'm proven wrong.
It is not an expensive toy. It is a more capable, safe, and longer lasting vehicle than any currently on the market. You can now buy a Tesla for less than a new and inferior Leaf.

Grasping at any reason to not purchase the better vehicle only makes you lose. I have nothing to gain from giving you good advice. You can lead horse to water but you can't make him drink!

You probably are listening to those who truly have an agenda or are trying to mislead you for monetary gain, but they are playing the tune that you want to listen to. I have no reason to mislead you. I can only try to explain to a fellow Leafer what my experiences are. Nothing more, nothing less...