Resound GN left side hearing and charger

The photo shows two hearing aids but the right one is not charging, it blinks and then goes out, its not the charger as its the same in both compartments so is likely the internal battery. Its being included in the package as not working. The charger is fine and the left aid is charging as normal. I dont know the exact model number, I cannot find it on the aids as the writing is too small for me to magnify. These aid that belong to friend on mine cost him £4500 when he bought them five years ago, so obviously they were top range aids at that time

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