The lesson is that if you are not entirely sure about something you are going to buy, buy it from a small retailer where you will sound advice.
I bought a second battery recharger and four rechargeable batteries from a large store within walking distance of home that sells office supplies. They were only alkaline and I knew they were a bit ‘iffy’ for use in a digital camera. But I would have thought that they would last like my old Arlec batteries, some of which are over ten years old.
But no. I eventually established two had failed. The bulging base of them gave me a clue. I could not bother returning them and it is just as well I didn’t as the salesman in Tandy told me that they were only good for about 25 charges. He steered me in the right direction, I hope, and I bought nikel whatever they are called, for twenty dollars for four.
Will see how they go.