Simple CR2032/CR2016 battery tester

thingiverse

Dead-simple Battery Tester for CR20?? Coin-Button Batteries. Provides a Low Load to Test the Battery. Bright LED = Good. The Little Prongs Sticking Out Can Be Used with Crocs Attached to a Voltmeter to Test Multiple Batteries in a Row. Materials Needed: * 100 Ohm Resistor (1-5%) * Rectangular 2.3x7mm, 2.5V LED (Kingbright L-153IDT or Equivalent) * 1 Paperclip 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 to Improve Stability of the Battery Contacts. When Cooled, Glue the Bottom Cap.