I must say a very big thank you to @menglxs!
I bought a pair of Oticon OPN S on Ebay some time ago. On delivery, one of them immediately charged but the other gave out the dreaded triple Red flash of death. For the last 4 months I have been looking rather forlornly at that charger and the deadly triple flash trying to source a new battery to no avail.
So as a result of this thread, I had my son fabricate a device as suggested by @menglxs. My son had a battery tray that he had previously bought from some electronics shop and used some wires, a “chip clip” (as we in Oz call a plastic clamp for resealing an open bag of crisps), two screws and a quick solder.
I was a big nervous as to what would happen while clamping up the dead Li-ion battery. But we went ahead and switched on power from the 3 batteries wired in series for 60 seconds. Then we removed the battery replaced it in the HA and then tried it in the charger. Success as the charge light came on solid Red! And after a few hours solid Green to indicate fully charged! 
What a great forum this is; and how much I have learned from all of you!
Cheers and thanks. 
First sign of success!
Fully charged…back in business.
