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Max Power vs State of Charge and Temp

dhanson865

Active Member
Feb 16, 2013
4,685
7,836
Knoxville, Tennessee
No, the EPA rating occurred long before the refresh. The only thing I can think of is a change in hardware (e.g. battery, BMS).

Don't you think Tesla can test the car and update the EPA specs prior to rolling it out to the public? These things have a lead time and require documentation. I wouldn't be surprised to see them out of synch.
 

AWDtsla

Active Member
Mar 3, 2013
4,266
3,960
NE
Don't you think Tesla can test the car and update the EPA specs prior to rolling it out to the public? These things have a lead time and require documentation. I wouldn't be surprised to see them out of synch.

EPA updates have happened long AFTER a change in the past. Take rated range on 90 packs, for example.
 

dhanson865

Active Member
Feb 16, 2013
4,685
7,836
Knoxville, Tennessee
EPA updates have happened long AFTER a change in the past. Take rated range on 90 packs, for example.

So?

EPA updates tend to be once a year. If cars are changed several times per year or even daily any significant change could be BEFORE or AFTER the EPA submission date.

I'm saying Tesla has a group that designs and tests cars and another group that deals with regulations. The regulation group probably just makes as few submissions as they can per year or possibly are limited by the EPA being only willing to accept so many submissions per year.

Consider most car manufacturers use Model Years and the EPA is probably geared to accept and store yearly submissions.
 

msnow

Active Member
Jul 14, 2015
4,951
2,236
SoCal
So?

EPA updates tend to be once a year. If cars are changed several times per year or even daily any significant change could be BEFORE or AFTER the EPA submission date.

I'm saying Tesla has a group that designs and tests cars and another group that deals with regulations. The regulation group probably just makes as few submissions as they can per year or possibly are limited by the EPA being only willing to accept so many submissions per year.

Consider most car manufacturers use Model Years and the EPA is probably geared to accept and store yearly submissions.
Your arguments don't make sense. Why are you ruling out that Tesla or a supplier could have made an improvement on the pack, BMS or some other hardware component? The "what is your 90%..." type posts from owners of new 90's (pre-refresh) starting this past January were saying that they were getting these unbelievably high numbers. People didn't believe them at first and asked for screenshots. In addtion Tesla updated their EPA numbers on their order page weeks before the refresh announcement. It's not the aerodynamics that did this.
 

msnow

Active Member
Jul 14, 2015
4,951
2,236
SoCal
image.jpeg image.jpeg
Too late for me to edit my post above but here are screenshots of the two 90 packs. The first one is the original 90D part number and the second is from a new refreshed 90D loner with only ~400 miles on it. I think this was a February build. They changed part numbers to go with what I think is an improved battery.
 
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AZ Desert Driver

Rare combination
Mar 12, 2016
1,335
715
Tucson AZ
Lets talk batteries some more....

I've asked this on another thread- but you guys seem to be much more save about Ludicrous operations and discharge cycle.

1) known degradation if one overcharges (100%) and does not discharge soon. Does degradation happen if one discharges rapidly, repeatedly ?
[as in hot rodding in ludicrous mode] i.e. - should one be cautious about buying a used ludicrous car?

2) The MS60 seems to be a 75 kWh pack. Seems like it is software limited to recharging to 80% of 75, or 60 kWh. But does this mean it cannot discharge 75 kWh? Is there any performance difference gained by buying the 75 kWh upgrade?
 

dhanson865

Active Member
Feb 16, 2013
4,685
7,836
Knoxville, Tennessee
Lets talk batteries some more....

I've asked this on another thread- but you guys seem to be much more save about Ludicrous operations and discharge cycle.

1) known degradation if one overcharges (100%) and does not discharge soon. Does degradation happen if one discharges rapidly, repeatedly ?
[as in hot rodding in ludicrous mode] i.e. - should one be cautious about buying a used ludicrous car?

2) The 2016 S60 seems to be a 75 kWh pack. Seems like it is software limited to recharging to 80% of 75, or 60 kWh. But does this mean it cannot discharge 75 kWh? Is there any performance difference gained by buying the 75 kWh upgrade?

75 kWh isn't power it's energy.

KW is power. The 2016 75 kWh pack can supply more power per millisecond than the old 2012 60 kWh pack, not because it has more kWh but because it has more cells or higher voltage cells. Check the label on the pack, some packs say 350V and some packs say 400V. That extra voltage means more power for the motor per millisecond.

Whatever power the 75 kWh pack can do it can do most of the time with or without the software limit. So paying extra for the pack unlock buys you range not performance. Though to access that same performance the car might have to be charged to the same miles remaining aka a higher % SOC on the software limited pack to equal the % SOC of the unlocked pack in terms of voltage.

OK looking at that there will be a very slight advantage if the 75 is charged to 90% because the software limited pack can't charge above 80%. But the difference will disappear if the 75 gets below 80% SOC. You'd have to micromanage the charge to keep it between 81% and 90% to have an advantage vs the 75 software locked to 60.

Performance in a Tesla peaks at 90% SOC and certain pack temp. Charging the 75 pack to 100% will give you more range but less performance than charging it to 90%.
 
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Old Man Mike

Member
Oct 7, 2015
189
170
Huntertown, IN
Lets talk batteries some more....

I've asked this on another thread- but you guys seem to be much more save about Ludicrous operations and discharge cycle.

1) known degradation if one overcharges (100%) and does not discharge soon. Does degradation happen if one discharges rapidly, repeatedly ?
[as in hot rodding in ludicrous mode] i.e. - should one be cautious about buying a used ludicrous car?

2) The MS60 seems to be a 75 kWh pack. Seems like it is software limited to recharging to 80% of 75, or 60 kWh. But does this mean it cannot discharge 75 kWh? Is there any performance difference gained by buying the 75 kWh upgrade?

Most everything you've seen posted around these types of questions are educated guesses based on standard LiPo battery experience. Tesla's battery technology is a significant step beyond the standard. I think most would agree that the worse thing you can do is charge to 100% and then leave the car in a very hot environment for an extend period of time. During operation (hot rodding), the battery temperature is monitored and cooling is applied if necessary or current is limited if it becomes too hot. This greatly reduces degradation. Only Tesla engineers can provide more detail than that, and they seem to consider it proprietary (understandable considering competition).
 

AWDtsla

Active Member
Mar 3, 2013
4,266
3,960
NE
October or November 2015 build here. Just tried 90% SoC with max battery power ready on firmware 2.22.75. 458kW max power, basically no difference from last December.
 

dhanson865

Active Member
Feb 16, 2013
4,685
7,836
Knoxville, Tennessee
What is the evidence for this claim?

Sorry, I left a qualifier out of that statement.

I said "Charging the 75 pack to 100% will give you more range but less performance than charging it to 90%" but I forgot to qualify that with something like "at or above a certain pack temperature".

Tesla limits pack output above a certain temperature/SOC combination. It isn't just temperature or just SOC and I don't know the formula to make a table or plot it but I do remember someone posting 0-60 times here in another thread and the regulars around here discussing the optimal temp/SOC combo for a run.

Assuming you are under or equal to the optimal temperature the opposite is true, a higher SOC will give better performance. I'm sure that's why my statement sounded odd to you.
 

bhzmark

Active Member
Jul 21, 2013
3,580
5,435
Tesla limits pack output above a certain temperature/SOC combination. It isn't just temperature or just SOC and I don't know the formula to make a table or plot it

See the charts in this very thread.

higher SOC --> higher reported kw.

So far the highest kw is from someone at 100% SOC.

TeslaPwr21.jpg
 
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bhzmark

Active Member
Jul 21, 2013
3,580
5,435
And those charts are labled with 2, count them 2 axis. One is SOC% and the other is KW. Note how neither of those axis is labeled pack temperature. I'll wait while you try to catch up.

Wow. Take a breath Mr. Hanson.

Note how Max Power HEATS the battery.

Note how the chart indicates colder batteries and unheated batteries yield less power (not on a different axis but those who take the time to study the chart key will repaid with the wisdom that battery temp is reflected in the chart thusly).

Note how it is common knowledge to people who own Teslas that overheated batteries reduce power and the dash indicates such a state with a dashed yellow line. It is hardly worth remarking on the fact.

So putting it all together the data reflected on the chart, and other anecdotal experience on this forum, is that hotter batteries and higher SOC batteries, yield more power, at least up to the point where they are overheated and the power taper kicks in in a very obvious way.

Short of that overheated power taper, I know of no evidence that power decreases as SOC increases above 90%, except, there is one poster who found (once? more times?) that his ET was lower when he charged over 94%. I haven't seen that replicated or reported by anyone else.

But I invite others to offer real experience, facts, evidence and data (as opposed to uninformed bluster) on this point.
 

ggnykk

Active Member
Feb 7, 2016
1,573
736
Earth
Just as another data point, the new 90D's are getting better rated range (about 10-13 miles) than the earlier 90D's from last Fall. I've compared part numbers on the batteries and they are identical but something is "new and improved" from previous cars.
It potentially could be one of them is in range mode, while the other one is not. Range mode affects the range number shown on the screen.
 

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