I don't recall where I got them. however I did make a point of finding good ones is an ocean of worthless Chinese junk, which abounds. I had to solder them up of course, in a configuration duplicating the original pack, so they would fit the holder properly. They're not just drop in. As I recall the 800 series was all 510V batteries, which are neither available or even reasonable to use. A 682S is one made under the name Rollei after Honeywell sold the name to them. It uses ordinarry AA batteries and is a thyristor model. The 700's were old style non thyristor. But what did I care? If the flash holds 70-80 flashes per charge, I need neither quick recycling or hundreds of flashes with a Graphic camera. I can't remember if mine is a 700 or a 710. Mine has the strobo eye built into the actual flash lens, with no provision for remote strobo eye. I bought it because I knew 1) I was handy enough to make up a new pack, 2) that sub C NiCad's are still available, and 3) being NiCad allowed me to use the original charger, which I would't be able to do with other kinds of rechargeable battery chemistry. Now I'm happy and it works fine. And my Graflite rings fit it perfectly.