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Cake day: June 4th, 2023

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  • Which is a fair claim to make. I don’t know why you went with “EV batteries aren’t safe over 40⁰C”, which is clearly False based on the source you cited, then went on a whole roundabout talking about how it’s not safe at 45C, then 70C, then how active cooling is inefficient while citing the efficiency of Peltier devices. Your top-level comment was fine. Nothing else you said after that made any sense.


  • A quick lesson on logical reasoning:

    If you want to show that a piece of technology A is inefficient and you know that another piece of tech B is more efficient, then you can use the inefficiency of B as evidence for the inefficiencies of A. Basically, for some inefficiency threshold T where any value above T is poor efficiency, then A>B and B>T means that A>T.

    Here, we’re comparing vapour-compression (A) and solid state (B) heat pumps. Solid states are much more inefficient. So you have A<B and B>T. You can’t use this to make any claims about the relationship between A and T.



  • It makes more sense if you read the context. They’re responding to a comment that said this:

    I guess you don’t understand active cooling then. If the coolest air in front of you is ~160⁰F, well that’s the coolest your batteries are gonna get, at best. Which is way hotter than rated temperatures for lithium batteries…

    A response that says “it’s not X” can be interpreted as “it’s not doing the thing you said it’s doing”. In this case, over_clox is saying that heat transfers directly from the battery to the air.