Not 100% sure but you have to attach leads to the cell tabs & I think they are aluminium.
Have you noticed these?
http://www.hobbyking.com/hobbyking/s...APPROVED_.html
In the reviews a guy mentions his using one for a 7 cylinder radial with success.
One thing has me puzzled, it has no balance leads & it's actually a 2 cell pack but they are wired in parallel to increase capacity, not voltage.
Perhaps it has some internal circuitry to balance the cells as they charge? - John.