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FlyF4
Son of a MX
Great, that should be accurate. You are doing something that the average Tesla customer has no idea how to check battery temperature, or even where the windshield wiper control is locatedI'm talking about the battery temperature of EACH string logged through the CANBUS. In my case, I'm using an Elm327 dongle with an adapter cable I made to Tesla's CANBUS connector. I'm using TM-Spy just like almost everyone else
Also there is another thread somewhere where the guy goes down a mountain like everyday since, ever, recently he started getting the limited regen, similar to when it's cold or high charge % but the car is within the normal operating range.
FlyF4
Son of a MX
Great info. Thanks for the external app chart. I don't see anything unusual, but perhaps someone will chime in. Regarding the regen limitation, I would expect regen to be limited when starting out, yet quickly go away after a few minutes and when the level gets under 95%.Battery temperature ranged between 70 and 80F. Is that too cold? Regardless, I've always gotten 80 amps up to that point on very hot or very cold days.
I've charged to 100% perhaps 6 times in the 50K life of the car.
As far as regen limited, I've made the same trip from my vacation house in Pinecrest a dozen and half times and never experienced regen limit (except starting out) in any condition including freezing temperatures or 100F degree days until the first time this fall. Have made the trip 3 times since and have had the same limit now all starting the trip with 90%. The limit always kicks in on that last grade before I hit Sonora.
This is the battery temp when I came to the first red light entering Sonora when regen limit with triangle first kicked in:
It started out around 50F and was regen limited due to cold for about the first 5 miles and then lifted as the battery hit mid 50Fs.
FlyF4
Son of a MX
hmmmm, sounds familiar, perhaps I saw that at one point. Sure, that can happen over time WITHOUT a firmware change.
Which is what I used to see. Regen was on at first until the battery warmed up some. I was at 88% when the regen limit kicked back in with the yellow triangle.
Interestingly, every time this happens, which is every time now from the same starting point, it always kicks back in on that last downgrade right before Sonora which makes it feel more like an artificial limit of some sort given the temperature and environment have been somewhat diverse.
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FlyF4
Son of a MX
Yea, that is interesting and I tend to agree it seems like some sort of artificial limit. I am more on the charger and supercharger end of the algorithms and electronics, so not totally informative, but I do have someone I can through a beer can at him to get his attention and ask. I'd like to know the answer to this as well. Can you tell me what is the charge level of the battery when you see that condition of regen limit kicking in? And how long (time wise) it that downgrade before it kicks in? Lastly, you may have already said it somewhere, but what model and year do you have? Thanks cheers.
Wow, I did not see that. Substitute kW for Amps in the list, which is what I misread, and it looks like it was charging at 80kW up until it was almost full.
A thousand pardons, @sorka
It seems you might not have read all of the posts as this was all covered previously.
Battery strings were 74F to 80F at the time regen limit came on. 30 miles of down hill mostly NOT regenerating because I was coasting which is why I went from 90% to 88%. The reason the battery is so cool is because I wasn't drawing much energy out or putting much in.
This NEVER used to happen even when it was 100F outside.
Veritas1980
Electric Viking
I would agree that something has changed with the taper in the high end of the charging at some point.
I have two 100% charging sessions logged with Teslafi. Both are with 11kW (three phase 230v) and I was charging from 90-100% for a trip in a underground garage so temperature is pretty similar. First charge was on 9th August and the second on 23rd December 2017.
On the charging session in August, tapering started at 98% and the battery was at 100% 37 minutes after tapering started.
For the charging in December, tapering started at 96% and the battery was at 100% 53 minutes after tapering started.
But in total time for charging, there is only 2 minutes difference between the two sessions, so no practical impact for charging in my case, but it looks like something has changed over time.
I have two 100% charging sessions logged with Teslafi. Both are with 11kW (three phase 230v) and I was charging from 90-100% for a trip in a underground garage so temperature is pretty similar. First charge was on 9th August and the second on 23rd December 2017.
On the charging session in August, tapering started at 98% and the battery was at 100% 37 minutes after tapering started.
For the charging in December, tapering started at 96% and the battery was at 100% 53 minutes after tapering started.
But in total time for charging, there is only 2 minutes difference between the two sessions, so no practical impact for charging in my case, but it looks like something has changed over time.
stopcrazypp
Well-Known Member
Try another cycle and make sure it's not something to do with balancing (more likely for someone who has not charged at 100% for a while).
I wonder when Tesla will just dis-allow charging beyond 90%, advertise the car's range based on that 90%, and be done with it.
Much like an anti-bricking buffer on the bottom end of the battery (capacity we don't see and can't use). Have a anti-tapering buffer on the top end to claim faster charge times to the "new 100%".
..so doing the math here... that would make my S85 with really a 77kWh usable from the factory, minus 10% for the new 100%, .hmm... a 70kWh battery. Advertised range would drop to 374km from a once-advertised 415km.
Would I have bought the car in 2014 if this were the case? No. My psychological barrier at that time was an electric car had to have range to make it between Calgary and Edmonton. Which is something it can just do if topped to 100%. (Edmonton to Calgary is uphill, so the harder direction to make on a charge. Calgary to Edmonton is an easy trip.)
Would I have bought this car today if this were the case, knowing the range was 374km? Maybe. The SC network is now in place, and there's a station mid-way between these two cities. Today, there are higher end options on the battery, I would probably pick the model 100D with the new 10% clipped usable of "90". If Tesla instituted this top buffer change they'd probably have to call this car the 90D. Not to be confused with the old 90D. Oh what a problem of baking a battery capacity number into the car model name!
Here's an elegant idea for Tesla to deal with degradation. Slowly raise the 10% top buffer invisibly to 9%, and 8% ... as the battery ages. Keeping the advertised range true and steady for longer, at the expense of now slowing the charge times with more pronounced taper. Until finally 0% remains on the top end and you're able to charge all the way to the top... The way we'd know the age of the battery on a used car is by how long it takes to charge it "fully". The car would show the same range throughout its life until finally the range does start coming down from it's plateau and that's when we'd know the battery is past peak and is now headed toward end of life replacement, or not, depending on what range is actually needed from the next buyer.
Sure they've thought of this, and played with 60's that can be uncorked to 75's. Tesla has settled on "let them use all the battery they bought" and is stepping away from putting capacity numbers in the car model name, a la model 3. This keeps the taper and degradation in our faces and is just something to deal with, as a physical property of the battery tech we now have.
Much like an anti-bricking buffer on the bottom end of the battery (capacity we don't see and can't use). Have a anti-tapering buffer on the top end to claim faster charge times to the "new 100%".
..so doing the math here... that would make my S85 with really a 77kWh usable from the factory, minus 10% for the new 100%, .hmm... a 70kWh battery. Advertised range would drop to 374km from a once-advertised 415km.
Would I have bought the car in 2014 if this were the case? No. My psychological barrier at that time was an electric car had to have range to make it between Calgary and Edmonton. Which is something it can just do if topped to 100%. (Edmonton to Calgary is uphill, so the harder direction to make on a charge. Calgary to Edmonton is an easy trip.)
Would I have bought this car today if this were the case, knowing the range was 374km? Maybe. The SC network is now in place, and there's a station mid-way between these two cities. Today, there are higher end options on the battery, I would probably pick the model 100D with the new 10% clipped usable of "90". If Tesla instituted this top buffer change they'd probably have to call this car the 90D. Not to be confused with the old 90D. Oh what a problem of baking a battery capacity number into the car model name!
Here's an elegant idea for Tesla to deal with degradation. Slowly raise the 10% top buffer invisibly to 9%, and 8% ... as the battery ages. Keeping the advertised range true and steady for longer, at the expense of now slowing the charge times with more pronounced taper. Until finally 0% remains on the top end and you're able to charge all the way to the top... The way we'd know the age of the battery on a used car is by how long it takes to charge it "fully". The car would show the same range throughout its life until finally the range does start coming down from it's plateau and that's when we'd know the battery is past peak and is now headed toward end of life replacement, or not, depending on what range is actually needed from the next buyer.
Sure they've thought of this, and played with 60's that can be uncorked to 75's. Tesla has settled on "let them use all the battery they bought" and is stepping away from putting capacity numbers in the car model name, a la model 3. This keeps the taper and degradation in our faces and is just something to deal with, as a physical property of the battery tech we now have.
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A firmware change in the last couple of months has changed the tapering behavior of my 2013 P85. I now see tapering starting at 90% when I didn't see that before while charging at 80A.
I totally agree. Tesla should build-in a 10%-20% "degradation buffer" and advertise only stable range. This way your car will always achieve the same range for years with no visible, consumer-facing degradation. That means a P100, with a 115 kWh battery but advertised, accessible, and visible range based on 100 kWh, should never see a range reduction over the likely ownership period.
And they will price it to match. Sounds like a good idea, but until the degradation happens, your carrying around a lot of extra battery and getting no benefit.
Excellent idea. In fact, I don't necessarily have to go to 100%. Just seeing if it tapers down to half the current at 93% should be enough.
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