Originally Posted by Kenny_G

IR only tells us a small portion of battery performance however. What happens to the Voltage Drop under a load tells much more of a reality on a packs performance. I have a couple of packs here that have wonderful IR numbers, but when I put a real life simulation (current draw) the voltage drop is higher than some other packs that have better IR numbers.
The difference is noted on the track as well ripping on our high bite straight