Introduction: Button Cell Octopus

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The Button Cell Octopus replaces button batteries.
This is useful when a replacement battery is not at hand.
It was used to run a thermometer and a humidity gauge from a 4 cents battery. Making this battery is also shown.


Supplies

Copper sheet (obtained from an Art supplies store)

Connection wire

2 Alligator clips

Soldier

For the battery:

4 us cents (2 or 4 being post 1982)

Cardboard

Vinegar

Tools

Hot glue gun

Soldiering iron

Scissors

Step 1: Make Connector

Make a connector to replace the button battery with another power source:
- Cut a strip of copper and shape it into a ring the same size as the battery.
- soldier the ring.
- Cut a small circle of copper to act as the top of the battery and to be the negative terminal.
- Soldier hookup wire to the copper ring and small copper disk.

Step 2: Hot Glue It

With the small circle of copper and its attached wire positioned in the center of the outer copper ring, fill with hot glue. This holds everything together and finishes the connector. The wires will either need to come out from the top or a nick will need to be made in the side of the copper ring for them to come out. This depends on the devise the octopus will be inserted into.

Step 3: Testing Connection to Device

Check the connector fits snugly into the devise and connects to its terminals.

Step 4: Add Alligator Clips

Solider Alligator clips to the connector wires.
Make another connector for a different sized button battery and soldier to the same alligator clips to form an octopus.

Step 5: Making a 4 Cents Battery

If no battery is handy, a low amp (2 milliamp) 1.5 volt battery can be made with 4 us cents.

  • 2 coins were made after 1982 - these are made of zinc and copper plated, so file one of the surfaces to expose the zinc.
  • 2 coins were made before 1982 - there are made of copper and will be paired to the zinc ones.
  • Cut 2 disks from cardboard, just slightly larger in diameter than the coins.
  • Soak the cardboard disks in vinegar.
  • Sandwich a cardboard disk between a copper and zinc coin, with the exposed zinc touching the cardboard.
  • Stack the 2 pairs together with the copper made coin being on top of each pair. Connect to the octopus and power the devise. E.g. calculator or thermometer.


If all coins were made after 1982, it will still work but you may need 4 pairs to achieve 1.5 volts. I like how just post 1982 us cent coins can be used either for it's zinc or copper properties and combined together to make electricity.

Step 6: Using the Button Cell Connector

The octopus connector can power devises which use a single button cell battery. I have used it to power:

  • Calculator
  • Thermometer
  • Hygrometer

Step 7: Upping the Volts

Red LED shown, at 4 volts, 2 milli amps.
Next day had dried out Milliamps down to 0.02. Added some more vinegar and wrapped battery holder in cling film. Amps went back to 2.5 Milliamps. Red LED glowed again.

Step 8: Update: Adding Another Leg to the Octopus

Today, I wanted to measure the temperature of some beer and found the food thermometer had been left on and the button battery was flat. As the button battery was a different size to my existing octopus button battery replacements, I made another leg for the octopus and another button battery replacement. Connected it to a 4 cent coin battery. This enabled me to use the food thermometer without a trip to the shops.