FYI: 18650 cells/manufactors compared

[NielsChr]

I found this site, witch have compared the different types of 18650 cells, It's in dansih, but the grafics is in english so asume most will understand - else you may use google translate

18650 batteri test 2011

Seam to me like Panasonic is a good choise for Tesla, Samsung is though also making a good battery as well

 

[TEG]

Samsung seemed to excel in a lot of ways, although the Panasonic seems to do better at very high current draw levels.
I suppose for very high performance automotive applications, behavior at high "C rates" becomes critical.

 

[NielsChr]

agree, if these messurements are correct, it seam like Tesla have selected the absolut best battery suplyer samsung is almost as good