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Earth Batteries for charging and lighting?

mtoffgrid

🧲 New user
Joined
Oct 9, 2025
Messages
4
Location
MT, USA
Anyone play around with Earth batteries?
Having researched it and built a few different versions that did work and then I built one to charge my solar battery bank as a backup. It works.
I have to say, it is worth it.
A few new books on Earth Batteries and going to expand it. This is going to get interesting.
Greenhouse grow lights, shop lights, yard lights, night lights, one for the office charging the laptop and run a LED lamp, charge the cell phone, and maybe some stairs and runner lights. Turns out Earth batteries are used in over 1800 communities around the world and also used in remote areas to run power for schools.
No joke. Who knew that? That might just be the future.
Lots of plans.
 
How much power are you pulling from your battery?
12 Earth Battery banks that goes into a 60 amp charge controller shows I am getting 15 Amps during the daytime and about 13-14 amps at night. 24 volt setup. Enough to sometimes top off the batteries if 9 hours, mostly around 90% depending how much I use the batteries before bedtime.
So charging a 24 volt battery bank of 6 of the 12 volt commercial D size batteries (1400CCA) with 13-14 amps or more at night ranges between 9 and 15 hours to top them off from 65%, which if I make another Earth Battery setup and hook them together in parallel, that will take it around half that or so in hours to top them off. And that is taking the batteries from say 60% and topping them off, so it is much less time when they are 70% or higher.
It depends on what I did that evening. How much power I used to make dinner or ran tools or ran a bunch of things in the house.
Since the days are getting shorter, the solar is not going as long as it does in summer so then it is just Earth Batteries or running on what is in the solar batteries to get things done in the evening.
You can go as big as you want with Earth Batteries, but it takes time and money. I am into it about $350.00 right now, but if I ran my generator with a battery charger at 15 amps I would use about $10-15 a night charging the solar system, but earth batteries are not costing me that money every night. Sure I have replace a few rods in about 8 months or a year for maybe $100. The only ones I have to replace are the magnesium rods. The solid copper rods are going to be fine. Upgrading with different rods that don't need replacing. More expensive, but get a lifetime or at least decades.
12 rows of 10 earth batteries. Bigger and longer rods for more amps.
Best thing to do is find a book that will tell you the types of metals that work best, the sizes, and how many you can figure on for your needs.
 
i've messed around with them before. got useful enough current to warrant learning more but never really scaled up like i'd like to. an earth battery powered ebike sounds interesting but likely impracticable.

i suggest you look into how to reduce graphene from graphite (relatively easy to diy) and add some to your earth batteries. i played with some math and the idea of embedding electrodes in concrete blocks doped with graphene for a sort of earth-supercapacitor, of course more of a home storage option rather than mobile, but if you already got the time and resources and are messing with earth batteries it could be worth it. maybe with aircrete it could be mobile? idk
 
Following this I read that a similar set up can harvest geomagnetic electricity along the Earth's magnetic field lines with little or no deterioration of the electrodes used. I don't yet see data on the length of the circuit (the size of the land) required to do this, but Wikipedia has references.
 
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