it’s like having bees. if you want to win the honey best it should be warm but not hot. then the honey flows best. if you do powersport … you should preheat your muscles. then there is no muscle pain. every cell structure has its optimal working climate. at li-ion it is 20 -35 degrees celsius. up to 50 degrees celsius no problem either. high current lipo (not bonka) perform best at 35 degrees celsius. In its own system, Kreisel has a liquid cooling system, heating to ensure precise temperature control. therefore, they are far ahead of all others in terms of the possible power delivery and cell lifespan. at eppg you don’t have to make things complicated. it’s easy too. just build a setup that fits. many show how to do it.
True. I would imagine they should work best at around 30 degrees Celsius. I’m just concerned that pulling over 10kw for a long duration while climbing a mountain side while it very hot could very quickly overheat a battery pack that doesn’t have some form of cooling.
The best way to control over heating a battery is with capacity. Adding capacity will split the work load and prevent it from getting hot. So I suggest you stop trying to figure out how to cool a battery and add weight doing it and add the weight of more cells instead. Then you have longer flight time and don’t need to get to altitude as fast as possible.
I used to fly with 4 Bonkas and the packs would get over 60c. Now I always fly with 6 packs and they barely get warm.
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The battery I will use will be about 34 lb. I am currently planning on a 14s24p setup or a 15s22p pack with Samsung 30q cells but even with that big of a battery 10kw-15kw constant it will get hot.
My total battery weight is 36 pounds and they don’t get hot even if I fly full throttle till they are dead (10-15kw). We are talking slightly different battery chemistry here but real world examples are more valuable than any estimations or calculations. In other words, you won’t know till you try it and I have tried it. Someone already suggested that you make the battery and try it and then if heat is a problem then fix the problem. You might be trying to fix a problem you don’t have. Also, other people on this forum have built packs and decided to add more cells later because they were overheating. Why would you rather add cooling weight instead of capacity? Take the lessons learned from others on this forum and add capacity.
Lion doesn’t handle high current as well as lipo so that’s all the more reason to either add more cells or design a system that is more efficient and draws less current.
I do intend going into this to add more cells later or likely just build a second battery pack so I can have 2. This battery should be in the 3.7 kw range. I would like to later increase the capacity by one kw or build roughly a 4.8 kw battery pack so I could get about an hour of flight time with a little bit smaller of a wing and playing around a bit with it instead of maintaining altitude at a slow speed.
I figure my motor, esc, and a bigger 4.7kw battery should weigh about the same as a fullt fueled 2.5 gallon fuel tank and a vittorazi 185
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I ordered the M40 motor and the esc they sell with it. I really wanted to use an MGM esc because of how programmable it is, but MGM took a few weeks to respond to my emails and when they finally did I had already ordered the other esc. 
I do want to later upgrade to the MGM esc but I may need to wait some time as I just spent over $900 on a different esc…