David,
Thanks for the information. It pretty much confirms a lot of my guesses.
I won't know how the batteries I have coming will react to the loads I plan until I get a chance to test them, but gut tells me that the higher capacity (Bigger Diameter/Length) cells are going to have a serious problem shedding internal heat so the 30mm diameter cells I have comming should perform better at heat shedding then the 40+mm cells. It will just take more of them for the same performance.
I would guess one reason is that the extended film length of the larger batteries is going to generate more heat and the larger diameter is going to slow down migration of heat from the core. I'm sure that part of the film used internally is a dielectric and probably a heat insulator as well
The above is probably just recovering the ground you already have, sorry about that.
It appears that the smaller cells do have a superior heat shedding ability, I assume just because of the smaller radius. I agree this probably explains a lot of the superior performance of the A123 in high performance. it also helps explain why why the A123s are the performance choice, even with the difficulty in building a pack.
With the heat buildup problem in mind I had been doing a bit of looking around and came up with this site
http://www.robfin.com/Products/PlainFin/tabid/85/Default.aspx
If testing shows that I'll have a heating problem in my Headways with the loads I intend, I had planned on taking a battery down to them to see if they couldn't come up with a cover, possibly self adhesive ot treated with thermal grease, that could wrap either a battery or stick of batteries. They can make this material in up to 24 inch lengths. Something that would allow us to come up with a reasonable cost alternative to the Life Tech. A fan placed at the end of a battery/stick of batteries and blowing down the channels formed by a wrapped folded fin heat sink should do a lot to control temperatures.
If you look at their spec sheet for the plain folded fins you will see that their is a large variation of what they can do. I'm sure some of the engineering types can help with thermal specifications on various configurations. They may have some generic material on hand that we can use for testing purposes.
You might try contacting them before you test your remaining three batteries and see if the have something you could use during your testing to see if they would help.
Those of us using the spiral wound cylinder type batteries will probably always run into a heating problem at one time or another If not during discharging then maybe during charging. If this is a viable, reasonably priced, method of battery cooling, we should all know about it.
Since you are looking at severe heating problems in your chosen use, I hope this helps. I would really like to see your name on an EV speed record.
Just a thought, for your land speed attempts, think about CO2 expansion cooling or even a dry ice cold box.
Jim