AA cell diameter differs

I got some AA to D adapters so I can use AA rechargeables with the RCA RC3000A digital boombox.



The cell I tried was a new Duracell DX1500 pre-charged rechargeable NiMH, rated 2400 mAh. It was a very tight fit, and hard to remove. These adapters lock in the cell when you push it in all the way. You can start removal by pushing on the positive contact, which is like a button. After that, all you can do is pull on the negative side, which sticks out a bit. It's hard to apply a lot of pulling force by hand to a cell that sticks out very little. When I finally got the cell out, I saw the adapter had damaged it.

My first thought is that the inexpensive no-name adapters sucked. Then I tried three other kinds of cells. They all fit nicely. There was a bit of friction with some, but it wasn't a problem. Also, there was no damage. Even the older 2000 mAh Duracell DX1500 (same model as the problem cells) fit properly. Here are the cells. Only the cell at the right has a problem fitting in the adapters.