How Do You Create A Battery Tester?
• Get some enamelled copper wire or wire obtained from the inside of a tubelight choke. Don’t worry about the length. • Wind the wire over a tumbler and remove, so that it takes the form of a spiral. • Attach the spiral together by a string at two or more places, leaving the ends open, and fix it vertically over a board. • Tie a razor blade with a string horizontally and hang it at the top of the wound coil such that the blade is parallel to the coil. Connect the two ends of the coil to any torch or other battery. The blade should deflect if there is current in it. If not deflected then it is a waste battery.
