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Sounds like Ludicrous upgrade may reduce incidence of catastrophic contactor failure

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Andyw2100

Well-Known Member
Oct 22, 2014
6,547
2,448
Ithaca, NY
I just listened to part of the Ludicrous mode announcement.

Musk said that the new fuse was developed with a its own battery and that it would constantly monitor current at the millisecond level, and will cut power when necessary. He said the new contactor was inconel, a high temperature, space-grade alloy, instead of steel, and that it keeps things springy under the heat of heavy current.

Based on what Musk said about the new fuse and contactor needed for Ludicrous mode, it sounds to me as if this combination should also improve overall reliability by reducing the incidence of catastrophic contactor failure.

Does that sound right to those of you that have more technical knowledge of this stuff than I do?

Assuming the above is correct, this could be an additional selling point for, say, a somewhat reluctant spouse who may value improved reliability more than increased speed.
 
I just listened to part of the Ludicrous mode announcement.

Musk said that the new fuse was developed with a its own battery and that it would constantly monitor current at the millisecond level, and will cut power when necessary. He said the new contactor was inconel, a high temperature, space-grade alloy, instead of steel, and that it keeps things springy under the heat of heavy current.

Based on what Musk said about the new fuse and contactor needed for Ludicrous mode, it sounds to me as if this combination should also improve overall reliability by reducing the incidence of catastrophic contactor failure.

Does that sound right to those of you that have more technical knowledge of this stuff than I do?

Assuming the above is correct, this could be an additional selling point for, say, a somewhat reluctant spouse who may value improved reliability more than increased speed.
I think spouses are worried about a lot of other things than contact failure.
 
I think spouses are worried about a lot of other things than contact failure.

I wasn't suggesting this would alleviate all of a spouse's concerns. I was merely offering one possible additional benefit to the Ludicrous upgrade, and asking if others more knowledgeable than me in these areas agree that these improvements should help with reliability.


Funny there were a couple of posts on one of the many Ludicrous threads arguing the exact opposite. The posters were not convinced that a microprocessor-controlled "e-fuse" could be more reliable than a traditional one.

That's interesting. I was merely inferring from what Musk said that we might see fewer catastrophic contactor failures. I guess that's not a conclusion that can validly be drawn yet.
 
Andyw2100;1077963... He said the new contactor was inconel said:
Interesting how much attention has been given to the fuse and not so much to the Inconel.

We do not know the specific Inconel version used, but we do know that Space X uses Inconel of some type in the engine manifold of the Merlin engine. Inconel has been used most often to avoid the high temperature 'creep' that normally happens with most stainless allows. Obviously low carbon, use of chromium and other very high temperature tolerant metals is part of the story. I strongly suspect that the Inconel choice is the more important part rather then the fuse. However, once the high threshold tolerance of Inconel operates precise temperature limits become essential too. Just as Elon said, though nobody reacted much, these changes are primarily about precision and ability to employ tighter tolerances. In other Inconel applications quite precise limit management is part of the successful implementation. ICE turbochargers and some common rail diesel components also are in the same category just as is the Merlin engine manifold.

Just from knowing some Inconel applications in aircraft engines I know that precise temperature limit control is the difference between long and happy life and disaster.

In another part of Elon comments he implied that Ludicrous implementation was an offshoot of the effort for a million mile battery pack. Thus I wager that they've really cracked some crucial durability factors, and JB recently said that battery cost was about to plummet. These are undoubtedly related as well as the chemistry changes as well as modifcations in anode composition. Probably a few other things too.

That the option exists only for P85D retrofit I surmise that the D packs have substantial changes from earlier packs even with the same nominal capacity.

In sum, I think this is a Big Deal and that Ludicrous part is just that we are focused on the least important part of the results. I have ordered it not for power but for better durability. The power is nice too.:love:
 
Actually, Musk said million mile "power train". I took that to mean the motor, not the battery.
Yes, you're right. I was recalling another Tesla employee discussion which suggested it was for the entire kit, including batteries, inverters, BMS etc. So far anecdotal evidence seems to suggest that Connectors, Fuses and inverters are the least durable parts, assuming I read various unconnected comments accurately.
 
I would like to see the Inconel upgraded contactors in my 60. Not for performance (obviously can't pull any more amps out of my pack), but reliability. One less thing to worry about, can't overheat them. I have yet to receive a contactor replacement yet... still have the original ol' clickity clackity ones. I would like to have the million mile powertrain parts :)