The metal camera suitcase (full size) I used has significant dents in it from Air Canada and CP Air, however they were unable to damage any of the cameras or accessories. A standard guitar case isn't likely to survive airport handling.
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Hansjörg von Gemmingen Roadster pack out of juice?
- Thread starter Model S Man
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- Tesla Inc.
The metal camera suitcase (full size) I used has significant dents in it from Air Canada and CP Air, however they were unable to damage any of the cameras or accessories. A standard guitar case isn't likely to survive airport handling.
His side of the story:
Story | Dave Carroll Music
I agree it is borderline blackmail (depending on whether he offered them not to publish videos if they settled), but I see nothing wrong with what he did up until that point (9 months into trying to get compensation) and nothing wrong with what he did in transportation.
Back to Mr bricker and Mr 200,000km - both those seem unreasonable claims to me (unlike Mr Guitar).
Vger
Active Member
I think the problem is in using your battery up too fast. One has to look at the offered $12k battery replacement (both the original Roadster offer, and the new Model S offer). That was priced assuming moderate use and a much longer calendar lifetime on the original battery. The current technology is just not suited for averaging 200+ kms every single day. I am expecting to amortize my Roadster and Model S batteries over seven to ten years. I have always assumed I would need to replace them, but not after having burned through them in just two to three years. One has to let the price curve on the technology function.
strider
Active Member
With my driving habits and California gas prices I save $3,000/year driving my Roadster. So with the $12k replacement then you break even in 4 years.
JRP3
Hyperactive Member
Hansjorg von Gemmingen is getting a new pack, at a discount.
Google translate:
http://www.manager-magazin.de/lifestyle/auto/a-897203-4.html
Google translate:
http://www.manager-magazin.de/lifestyle/auto/a-897203-4.html
JRP3
Hyperactive Member
I find it interesting that it seemed to degrade quickly to 100km of range and then apparently held there for two years or so, since it seems he's still driving it with that range. That suggests to me a module failure and not a total pack capacity loss.
Apparently he range charged the car very frequently, and also deep discharged the pack. This was per one of the interviews that he did a few years back. I also though I read that he had the pack degraded to about 100 miles at that time. I don't know where the 100km came from. I wonder if somebody is confusing miles with kilometers.
JRP3
Hyperactive Member
The original German piece linked earlier in this thread listed 100km, and being German that makes more sense than miles.
To clarify, I believe the 100km he has now(around 60 miles), but I don't think it's accurate to say that he has been at that level for two years. I think that two years ago he was at about 100 miles. I'll have to dig that article up...
JRP3
Hyperactive Member
It's right here, from the first page of this thread: http://www.welt.de/print/wams/motor/article109822065/Durchgefallen.html
You might be right then. Still doesn't make much sense that the battery degraded that much, and has stopped degrading.
JRP3
Hyperactive Member
We know that capacity is limited by the smallest parallel group of cells, so if one of those groups experienced some cell failures which limited capacity that could explain it. A sudden failure like that would also explain the quick range loss that does not continue to degrade.
Tesla should be able to tell if a sheet is bad... and replace just that sheet. I had a conversation with a Tesla Ranger on this very subject and he said that they have done pack refurbishing by replacing individual sheets with comparable age sheets as the rest of the pack.
djp
Model 3 Performance
Agreed, the battery is limited by the weakest brick, so ideally replacing one failed brick can bring the battery back up to full capacity.
The pack is designed as 11 sheets of 9 bricks, and the sheet is the smallest replaceable module. This could mean throwing out 8 good bricks to replace one bad one, but still better than buying a new pack.
The pack is designed as 11 sheets of 9 bricks, and the sheet is the smallest replaceable module. This could mean throwing out 8 good bricks to replace one bad one, but still better than buying a new pack.
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The common assumption is that capacity is limited by the smallest parallel group of cells, but we don't know that for sure. There is actually lots of evidence that the cells in a brick may not always be connected in parallel. Instead it's quite possible that the ESS is composed of 69 parallel strings of 99 cells in series. This design would make it easier to balance, allow much cheaper and more robust transistors that connect/disconnect the cells, and potentially allow for a more graceful failure of the ESS.
I disagree with this analysis if the bricks are made up of 69 cells that are always connected in parallel. In fact quite the opposite would happen. That's where I got my so-called runaway failure theory. Assuming each brick is 69 cells permanently connected in parallel, if a few of those cells failed or became weak, then the remaining cells in that brick would have to make up the difference. That would put more stress on those remaining cells because they would have to carry more current with resulting heat, and be discharged to a lower SOC every time you drive. Those are the two worst things you can do to the cells, so the remaining cells in that brick would decline much faster than the rest of the pack. This decline would accelerate with each discharge cycle. The result would be a runaway failure of sorts. But keep it in perspective - this would still be a rather slow runaway, at least at first.
stopcrazypp
Well-Known Member
This architecture would require you to monitor and balance each individual cell because the 99 cells in series in each brick all have a risk of being over-discharged (in top balance case) or over-charged (in bottom balance case). And given the strings are all independent (the only commonality is the overall pack voltage), that essentially means you have to monitor and balance all 6831 cells.
The assumed architecture where 69 cells are in parallel per brick means these 69 cells self balance and can be monitored as a single group. The BMS then only has to monitor 99 bricks, rather than each individual cell.
stopcrazypp
Well-Known Member
There's something else that's more critical that I forgot to mention. If the 99 cells are in series and one cell fails (and cells tend to fail with a high resistance, which is close to a open circuit) that makes the entire brick unable to function.
In the case of the 69 cells in parallel, a failed cell only means slightly higher load for that brick, but the other cells are still able to function.
In the case of the 69 cells in parallel, a failed cell only means slightly higher load for that brick, but the other cells are still able to function.
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