[Arct1k]

IIRC it is a 2mm Bullet in the middle...

I would make a custom deals harness - i.e. create a short deans extension lead male to female deans. The wire the hyperion tap into the deans extension - red to red, furthest from black to back deans and the middle back to the 2mm bullet.

I think I'd be inclined to get that pack back up now by hacking together a direct charge lead for the dodgy cell - i.e. 3mm bullet lead off the centre of the pack and a single wire to a male deans either on the red or black side depending on which cell is 0v. I'd then just use the NiMH mode at .2 amps to get the voltage up...

Or just do as Jeff said .2-.5 amps across the whole pack to the volatge up...