Great idea. Something like this here. That will do good enough for me. Thanks :)
EDIT: Finally broke down that 40V pack I pulled from a HD recycle bin. Every cell, except 4, was at 4.07v. The other 4 were at 4.06v. Before breaking down the pack, the pack voltage tested at a little over 18v. So I expected some bad cells. Did a quick test of internal resistance on a few and they were in the high 20's to low 30's cold. If they are all good, I'll build a 4S4P pack that will be used to power a big HID light. When not in use, the pack will also kept in the trunk for jump starting purposes. The 2 cells missing from the below picture are in the process of being discharge tested.
Date codes are:
K3D3
So March 2013, if I follow sixty545's date code theory correctly.
EDIT2: If you ever come across one of these packs, grab it. Seems the control board in it must have failed or bricked out the pack, because the cells are behaving like they are almost new. So far 4 cells have been discharge tested and all are just under 1.3 Ah (1280 - 1296mAh) and have low internal resistance. I'm expecting the remainder of the cells to behave the same. So I will only report back again if any surprises arise.