Yeah, completely forgot about this one.

http://www.horizonhobby.com/products/TMEXTRMPB

Its what I was thinking of. Wouldnt work with the charger Ihave though, it needs the balance connection to detect the number of cells unless Isetup a special Lipo setting under the manual settings. Too lazy and the chargers I have for the UM packs work just fine for my needs.