How to Make a Soil-Urine Battery With Load

Is it possible to use earth or soil energy to power small homemade appliances? This research project gives an answer, although the battery endurance test is still in progress.

A soilurinebattery will not solve the world energy problems. But research into 'Soil Power' applications are very interesting because of the simple design and the easy to get, cheap components. I made two ultra low-power test devices as load . The basic battery consists of 4 soilurine cells. Enough to power kinetic devices for hopefully a long and moving life.

News:March 28-2023, the pulsemotor on top of the soilurine battery is already running for 123 days or 4 months. That is un-expected long... and the battery is stil going strong. I added 2 months ago a cup water pro cell. That's all.

Supplies

Partslist:

• 4 flowerpots (bottom closed)
• 4 zinc or galvanized plates, 6 square inch min.
• 4 coppertubes 0.5 inch diameter min.
• 4 feet copperwire
• moist garden soil later mixed with urine
• Possibly a load to show that all is running well.

Step 1: Project Video

The video shows the making and use of a soilurine battery

Step 2: Soil Battery Construction

Making an Earthbattery is done in a minute; push a copper and zinc plate into garden soil and you immediately measure a voltage. You must use a plastic- or glass jar to galvanically separate the batterycell if you connect them in series. I made first a test batterycell in a plastic yogurt yar with florists earth; see photo. Then I connected 4 cells in series and the voltage was indeed four times higher as the single cell.

One electrode is made of zinc or galvanized iron and the other of coppertube. That metal can be found in every major hardware store. It just needs to be sized to fit your yar. The photo shows how the coppertube is connected by an isolated copperwire to the zinc plate. I used a poprivet to connect the wire to the electrodes. It is important to place the individual cells in a container. The plus and minus pole can then be attached to a fixed clamp.

Step 3: The Soilurine Battery

The video shows what happens when adding a cup of human urine to the soil. When measuring the voltage not that much happens but the short-circuit current has raised with minimal a factor 3. The shortcut current is an indication of the energy content of the battery. No urine smell is left because the neutralising power of organic soil .

Step 4: Kinetic Objects As Load

For the sake of clarity, we are talking about tens of microWatts of load used here. I made before some ultra-low power (ULP) solar windowsill devices, so I have some experience in the field. I don't go in detail here about the construction of the devices used as a load. It is only to show the wonder that this simple soilurine battery is setting devices in motion.

Step 5: Measurements and Circuit

1- Measurements on pure garden soil battery cell:

Voltage: Depending on the earth, between 0.8 and 0.9 Volt

Current: Shortcut current 1000 microAmp on average

2- Measurement on gardensoil mixed with urine:

Voltage: Pro cell between 0.7 and 0.8Volt

Current: Shortcut current 3000 microAmp in average.

The shortcut current is an indication for the capability

The circuit shows 4 batterycells in series giving about

3.2 Volt to the circuit. The internal resistance is high.

The pulseshaper circuit is simple. RV must be set for

the best pulse, indicated at the LED.

Step 6: Conclusion

Without power from other sources, motor and pendulum are still running on a battery of urinated soil. How long this devices are moving till the battery is exhausted, I don't know. The idea, to power a wireless IoT sensor with a soil battery, is not yet made to a practical application. This project shows a beginning to explore that.