LCD calculators draw very little current. Our vinegar battery easily runs these devices.

Take the back off of an inexpensive calculator, remove the battery, extend the two battery wires out the sides then reassemble.




Wires extended. Important: note "+" and "-" ends of wire.


Build two battery cells using copper wire and galvanized nails. Parts: 1 - 10 cm copper wire (small gauge), 1 - 15 cm copper wire (small gauge), 2 - 2" galvanized nails, 1 - 10 cm regular insulated wire (20 gauge).


Note the copper wire from one battery connects to the galvanized nail on the other. The copper wire is the "+" terminal of the battery.


We used a piece of breadboard to make connections. The battery assembly ready to be connected to the calculator.


Connected to calculator. Make sure copper wire is connected to "+" wire of calculator.


Electrical tape and thumb tacks secure the assembly.


To fill the battery cells, remove the wires from the bread board. Lift the caps off and carefully add regular vinegar. Avoid spilling vinegar on the calculator!


Here's a video.