Have you ever been reading with a book light at night and found it to be too bright? Here's a simple way to dim your book light without permanently changing it. This method reduces the amount of voltage supplied to the light, thus reducing the brightness. This will work with book lights that are powered by two button cell batteries.
Step 1: Gather Your Supplies.
Step 2: Remove Battery Cover.
Step 3: Take Out One of the Batteries.
Step 4: Get the Foil.
Step 5: Fold in the Corners.
Step 6: Fold Them in Again.
Step 7: Shape It So It Is About the Same Size As the Battery.
Step 8: Install the Shaped Aluminum Foil Over Top of the Existing Battery.
The aluminum foil is acting like a spacer. It conducts the electricity, but doesn't add any additional power.
Please note that only one of the original batteries remains in the book light.