Earth battery

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Earth batteries

How-to make batteries from soil

「 H&D in collaboration with Hackitects (Michel Barchini, Mary Farwy)」

Making the Cathodes

To make the cathodes you need the active coal, epoxy glue, metal nets and electric wires.

1. First empty the pills of the active coal provided to get the powder out, and place it on a sheet. (about 10 pills powder per 1 cathode disc)

1. Secondly, cut two net in a rectangular shape 8 x 8cm. Place them in opposite directions and fold the edges so they are attached. We make two layers so it can hold the glue and coal well.

1. Then brush the glue on the net and make sure that you add enough glue and that it is brushed evently on the surface of the net.

1. Cover the brushed net with the active coal powder and press it very well. After pressing, add coal and press again. It is very important that the coal is covering the whole surface.

1. After making sure that all the net is covered and pressed with coal, connect the net from one of the sides to an electric wire. At the end you might need to bend the net to fit your container. Bend it, but be sure not to make the edges touch each other. More coal surface is better! Now leave it to fully dry.

Preparing first part of the Soil Battery

For this step you need the container (glass jar), mud, the dried cathodes.

Image: on the left the finished cathode, on the right two glass jars half filled with mud, with a wire from the cathode coming out of the opening

First put the cathode in the container (make sure that the glue dried and the coal is stuck to it). Secondly, fill the jar with mud so it covers the cathode, keeping the wire out of the container. Mark the wire with tape to identify that its negative. (black = negative) Then hit the container to get all the trapped air bubbles out. It is VERY IMPORTANT to release the air bubbles from the mud.

Making the proton exchange membrane

Grid of images showing the process of preparing and pouring the agar described in the steps below

Image of a mud battery in a glass jar: half filled with mud, then a layer of solidified agar, and filled to the top with clean tap water. Two cables are coming from the jar and are connected to an LED for illustration purposes.

Connecting the batteries in parallel

The water part in the battery is (+) and the mud part is (-). When connecting two batteries in pralel the (-) from the first battery should be connected to the (-) in the second one, and the (+) from the first to the (+) in the second. Then the (-) and (+) should be connected togather to close the circuit. See the drawing:

Image: Diagram of two mud batteries connected in parallel: the cathode (or minus, black) comes from the mud of battery one and is connected to the cathode of battery 2. The anode (or plus, red) is the wire sitting in the top half in the water, and is connected to the anode of battery two.