How to Make a Battery Tester

Step 1: Materials

For this you will need:
Small light bulb (I got mine in a small science kit
2 Alligator Clips
Rubber band
Battery to test

Step 2: Attach Rubber Bands

Attach the rubber bands to both ends.

Step 3: Attach Alligator Clips

Attach the alligator clips. Make sure they are touching both the positive and negative sides.

Step 4: Attach Clips to Bulb

Attach clips to bulb.

Step 5: Testing

The brighter the bulb is the more juice is in the battery.