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Discussion Starter · #481 ·
The heat transfer plates between cells (conducting heat to the plate with liquid circulating in it) in pouch cell modules is normally thin aluminum, and covers the width of the cell from the plate, so typically twice the height of an 18650 cell.


Your call, and I understand the issue with joining the fin to the base plate, but without curving around the cell contact between the cooling fin and the cell case will only be a line - no area. Between the fin and the rest of the cell case is whatever you use for potting, but as I noted before...


The Tesla cooling snake only follows the cell wall for less than one-sixth of the cell circumference, but that's a lot more than line contact. That plates (fins) are a natural match for pouch cells, but not for cylindrical cells.

if you see the Tesla snake cooling line it is an eye opener. I can't believe there is much water flow at all, in addition it is wrapped in a thick ribbed rubber jacket. So whether it touches 1/6 or less I have doubts it is significant at all. I think the potting is doing the lions share.
 

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There's low pressure flow there, obviously. But, yeah, I knew you looking at a chunk of it would 🤯

Again, half the job is cooling, the other half is in preventing a rogue cell from making the module go China Syndrome. You guys keep thermal coupling the cells. You DONT want to do that.
 

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Discussion Starter · #483 ·
on the last concept I have plastic spacers keeping the individual cells apart as well as away from the heatsink metal surface, this void will be filled with potting, so they will be spaced, more than the tesla cells, its hard to see but at the bottom is a square spacer that the cell rests in, at the top the black part on the top of the heat sink fin.
 

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if you see the Tesla snake cooling line it is an eye opener. I can't believe there is much water flow at all, in addition it is wrapped in a thick ribbed rubber jacket. So whether it touches 1/6 or less I have doubts it is significant at all. I think the potting is doing the lions share.
What do you think the potting is doing? It can only conduct heat to somewhere, and that's the cooling tubes. The "thick" jacket is nothing compared to the potting.
 

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on the last concept I have plastic spacers keeping the individual cells apart as well as away from the heatsink metal surface, this void will be filled with potting, so they will be spaced, more than the tesla cells, its hard to see but at the bottom is a square spacer that the cell rests in, at the top the black part on the top of the heat sink fin.
It fundamentally makes no sense to me to install a cooling system, then to go to great effort to insulate the cells from the cooling system as you are proposing here. :unsure: No commercial manufacturer of battery modules does that, and I'm not surprised.
 

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Discussion Starter · #488 ·
It fundamentally makes no sense to me to install a cooling system, then to go to great effort to insulate the cells from the cooling system as you are proposing here. :unsure: No commercial manufacturer of battery modules does that, and I'm not surprised.
All I am saying is, if the Tesla snake is only touching 1/6, then the other 5/6 is touching the potting, epoxy, whatever. How can that be discounted without knowing the material and its K?
 

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The Tesla snake is NOT touching 60 degrees of arc, which is a number Brian made up; I doubt it's even contacting 30 degrees.

Look at the indentations of the cooling tube sample I sent you.

The K doesn't matter a lot in this design. It plays with delta T.
 

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I'm just going to drop in and say it again. Tesla's cooling works great for a 8c cell. It removes enough heat, and can add enough heat back in when needed. My feeling is the insulation is needed more for the cold then hot conditions. A big part of tesla battery management is by throttling the motors to not allow them to draw too many amps, and there for make too much heat.

Is the tube ideal, no. But it is designed to their use case, and in my book that's called good engineering.

Now if you want to use 30c cells, you need other options. Like immersion, evaporative, or massive air flow through them. None are trivial.

Bob
 

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Discussion Starter · #491 ·
Hi Bobwind, thanx. I have put this on the back burner for a little while to concentrate on some other things in the shop in prep for the corvette project. I have a car to get rid of (63 Avanti) and I want to get a car lift installed as well. I hope to still purchase a Tesla LDU this year and then I can get the adapters finalized and machined, this is my plan for now.
 
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