Plant Battery Project

[kennenmc]

Good afternoon - my green team is working on creating a plant battery. We had set up a potted plant with potting soil and compost from our worm bin and connected copper tubing on one end and a magnesium rod on the other side. When we connected a Vpro850L multimeter we got a reading of .86 volts. We are trying to light a standard electric circuit kit bulb in a holder. The bulb lights with a 1.5 volt battery which we also tested with the multimeter (1.46). Our idea was to create a second plant battery - identical to the first, connect them together and use them to light the bulb. When we connected them, we tested them together with the multimeter and got 1.6 volts, however the bulb did not light. I am curious to know if there is any component of the system that we are missing. Any advice or suggestions would be tremendously helpful. Sincerly, PS150Q Greenteam

[bfinio]

Hi,

If you haven't already, I would recommend reading through our potato battery project, which is basically going through the same procedure you're doing but with potatoes instead of potted plants:

https://www.sciencebuddies.org/science- ... to-battery

That project's introduction section and procedure go into more detail, but long story short in order to turn bleep on you need enough voltage but you also need enough current. You can get more voltage by connecting battery cells in series, as you've demonstrated. However, that does not guarantee you are getting enough current to turn the bulb on. Even though AA batteries also produce 1.5 volts, they can provide much more current than plant/potato batteries.

There are different ways you can experiment with increasing the current, like adding more battery cells in parallel or increasing the surface area of your electrodes. You can also measure the current through the bulb when it is connected to a 1.5V battery to get a sense of how much current you need.

Hope that helps, please write back if you have more questions!

[kennenmc]

Thank you so much!