Here is how I did it, it could be useful to others:
- Once the razor unscrewed accessed on drums shaped AA battery,
- You must be careful desoldering (not heat what is around)
- I cut the contact strips to leave about half a centimeter,
- I took the new battery which I remove the jacket on the slides,
- I fanfold slats of the new battery once unsheathed,
- I placed it between the remaining from previous lamellae (the accordion folding allows a safe contact)
- I soldered at the contact point between the old and new strips,
- Screw the whole,
- Put the shaver charge
- And voila :)
