I use rechargeable Ni-MH batteries in my camera.
When they are being recharged, they get quite hot towards the end of the charging period, almost too hot to hold, maybe around 45 or 50°C.
1. Is this normal, and safe?
2. What is the optimum charging temperature? Is it best to allow them to get this hot while charging, or is it better to charge them in a colder place so that they are able to keep cool off as they charge? Or would it be better to insulate them so they can get even hotter as they charge?