Ah yes, the free battery a month club card. I fondly remember those cards and the RS beach balls too. I also had a couple of RS comic books about technology and space. Oh, and the free flashlights too (no batteries though). These were awesome to get as a kid and teen. For the free battery a month offer, from age 9 I realized that the 9V battery was the best battery one could get because it didn't need to be paired with other cells and had the highest voltage, which made it better, right? They were the red cells, carbon zinc IIRC, but they were decent for the time. The green and gold cells were better but cost more. And for OP, I used to have those old 80s NiCd rechargeable cells and the RS 4-cell charger to go with them. I had 4 AAA, 8 AA, 4 D, 4 C but no 9V from RS. My 9V batteries were made by Panasonic and I had 3 of those. I managed to get quite a lot of charges out of all of these batteries before they grew whiskers inside them and shorted out. Much better life than later NiCd batteries I purchased from other manufacturers. I really miss RS/Tandy.