UK battery pack- rebuildable?

[Furnari]

I've got a rechargeable C-8 that I picked up used with a battery pack built in 2002. Right now, I can barely get an hour out of it- are these things rebuildable? Related question- does it make sense to convert it to the eLED module?

 

[kiknads]

Yes, its basically 8 rechargable c cell batteries wrapped in plastic