Here are some Chiller Plates designed to fit Chevrolet Bolt battery modules. My neighbour is doing an EV conversion for his John Deere 4020 and he wanted to use Chevy Bolt modules because of their useful shape and amazing specific capacity. The OEM ones are from stamped aluminium and they aren’t that great so I designed some. We got 10 made for a price of less than $500 so they are quite cheap and they work really extremely well.
This design can easily be carried over to other battery designs specially as most upcoming EVs use pouch cells.
The number, size and fins will depend on your application. The number of fins you or even if you need fins depends mainly on the mass flow rate of the coolant and how you interface the cooling plate with the battery…
In our case we are using thermal pads between the battery and the cooling plate with a thickness of 0.5mm and a conductivity of 5W/(mK), which gives coefficient of heat transfer of 10kW/(m2K), this is more than double that of the coolant(water) flowing through our system which is ~4kW/(m2K). So in our case we do benefit from fins. However, if we were to just fasten them on to the battery we wouldn’t get any benefit from adding fins since the air gaps are the bottle neck.
I have added the CAD file below. Let me know if you have any doubts. Please acknowledge me if you plan to use it.