August 24, 2018
Description
Dead-simple battery tester for CR20?? coin-button batteries. Provides a light load to test the battery. Bright led = good.
The little prongs sticking in the front can be used with crocs attached to a voltmeter in order to test more conveniently several batteries in a row.
Materials required:
Construction:
Print the holder. Cut the paperclip in two, separating the two V-shaped parts to be used as contact points. Stick the two halves in the battery slot, sliding them through the holes. Cut the ends to size, leaving 3-4mm for soldering. Insert the remaining bits from the paperclip in the front holes. Insert the LED, respecting polarity (as shown in the diagram image). Bend the positive leg of the LED and solder. Use the 100R as a bridge between the battery and LED on the negative.
Fill with hot glue in order to improve stability of the battery contacts.
When cooled, glue the bottom cap.
License:
Creative Commons - Attribution
wavexx
