What did we use before the AA battery was invented? I have three computers; each computer has a wireless mouse that uses two AA batteries and two of the computers have wireless keyboards, they use four batteries each.
I needed to replace the four AA batteries in the camera and the four AA batteries used by the flash.
I went to turn on the AC and discovered the household thermostat batteries needed replaced. The thermostat required three AA batteries. I have a wireless thermostat that tells me the outside temperature but the batteries went dead, it was two more AA batteries to tell me the AC should be running.
I opened the junk drawer in the kitchen, every kitchen has a junk drawer, and noticed the flashlight had exploded. The flash light was at least ten years old and the plastic threads where the top is screwed to the body had separated . I went to Home Depot and selected a replacement flashlight. The new flashlight can use one, three or six LED's depending on how much light is required and it can use three, six or nine AA batteries. Lucky for me Home Depot sold AA batteries in a twenty pack.
I've replaced almost forty AA batteries in the last three weeks and the wireless rain gauge displays the low battery symbol; that means two more AA batteries and another trip to the store.