AAA batteries can replace AA batteries by enlarging the size of the casing. There are a few different ways to go about doing this. Which one you choose will depend on the amount of time, money, and effort you're willing to spend. Here is some information to consider when making your decision.
1. By Hand
If you wish to do this by hand, you can do so by enlarging the size of the AAA cylinder.
- Cut a ¾-inch by three-inch piece of paper.
- Roll up the paper around your AAA battery as tightly as possible.
- Roll 19 inches of electrical tape over the paper.
- Make a second cylinder out of tin foil.
- Get a ⅜-inch ball of foil to fit on one of the sides of the cylinder.
- Crush the foil flat after putting your AAA battery in the cylinder.
There are adapters that can be used as well. These are fairly cheap and don't require any extra work. Simply fit your AAA into the shell.
3. Pros and Cons of Adapters
Adapters are easy to use and put together. However, you need to look out for the metal piece, because it can fall out. The shells are also just a little bit bigger than a AA battery. These shells may not fit into every compartment.