This instructable has been in the works for quite a while and should have been finished when I did version 1. But I'm so lazy so it didn't come out when it should have, yada, yada, yada. Also if you want to make this for a bigger battery you should adjust the dimensions accordingly.
Any way, enjoy!
Step 1: Materials and Tools
An Exacto Knife or scissors
You also need:
Aluminum foil about 8cm long and 2cm wide or 4 inches long and 1 inch wide
Cardboard from a cereal box about 6.5cm long and 3cm wide or 2.6 inches long by 1.2 inches wide
I reccomend you use the metric measurements because they are a little more exact and they are the only measurments I will use from here on out. Also don't cut out your materials just yet as you may need a slightly larger piece.
Step 2: Measure Your Cardboard
First take your cardboard and and make a horizontal line about 6.6cm long.
Then make a vertical line at one end of the horizontal line. The line should be about 3cm long.
Then make an identical line at the other end of the horizontal line.
Make another 6.6cm line on the ends of the vertical lines to make a box.
Also make 2 tick marks on each vertical line. Each one shoulbe 1cm from the horizontal lines closest to them.
Connect the tick marks directly opposite of each other with lines 6.6cm long.
Make more tick marks 1cm from from the vertical lines. These will allow you to make the vertical lines you will need in the future.
The future has arrived! Make those vertical lines along those tick marks.
You should now cut out the entire thing along the outside lines.
For further clarification refer to the pictures.
Step 3: Cut and Fold Aluminum Foil
You should then fold each piece in half so then they are 4cm long. Then valley fold in half and unfold. Then mountain fold one end to the crease previously created. Each pice should now have 2 pieces 1cm long and 1 piece 2cm long.
Refer to the pictures if you need clarification.
Step 4: Score the Cardboard
The sequece for folding the end tabs is as follows:
The sequence isn't that important but it does help with the overall effect.
Step 5: Cardboard Meet Aluminum Foil
Wrap tape around the sides as seen in the third picture. Then cut the tape in the corners and fold down the tape onto the bottom.
Step 6: Done ^_^
Congratulations and Enjoy!