By breaking open either Duracell or Energizer (I don't know about other types) you can save money.
Step 1: Gathering Materials (And Some Notes)
In order to do this you will need
A 9-volt battery
A mini flathead screwdriver (Optional)
Conductive and easily crusher material (I used aluminum foil)
A small dish (To hold metal shavings)
An aaa battery (Optional, but it makes it way easier to size the battery padding)
Note, to clarify, you will not be prying open any cells (The things with battery acid inside) you are just prying open a battery. You will not need to do anything with acids.
Step 2: Getting the Cells Out.
Pry off the bottom (the side that doesn't have the connectors) of the 9-volt battery, remove the small piece of black plastic, then pull out the 6 plastic wrapped 1.5v cells.
Step 3: Seperating the Cells
Take the pack of cells and pull the black piece connected to the batteries off of them. Then cut or rip off the plastic wrap on the cells.
Step 4: Seperating the Cells, Part 2
Pull on the two pieces of metal poking up from the pack of cells until one of the pieces of metal holding the cells together breaks. Using your pliers, pull all the pieces of metal off the cells. Make sure to keep track of these as they are very sharp.
Step 5: Bulking Up the Cells.
Ball up a piece of the foil so that it has a form something like _A_
Now put this on the side of the cell that doesn't have a bump. Strangely enough, this is +
Then wrap the whole thing with duct tape until it is approximately the size of the sample aaa. Cut off the extra and you have a AAA battery!