This is intended to be the beginning of a series of posts about making batteries from home. It is going to include a series of test in order to determine the best types of home made batteries to use to power my home. The basic objective is to make a battery bank large enough to power several 12 volt lights and appliances throughout my home. I don't intend to power any large appliances yet, however that may be a goal for the future. For now, my intention is to be able to power at least enough lights for up to 5 rooms, two internet routers(a cable modem and a wireless router), a 12 volt cooler for food, a PC and a TV. For me, those are the bare necessities and I can live quite comfortably with just those things. Others may require more, but this is my house, not theirs lol.
I have already performed some general experiments with different sized containers, different types of container materials, different metals and various electrolytes. Below are my basic discoveries to get us started.
How to make a basic home made battery
To make a general purpose home made battery you generally need to make several cells. For this demonstration, we will use one 12 oz pop cans for each cell in our battery and we will probably use 6-8 cells depending on how much power is needed.
- 6-8 12 oz pop cans(preferably generic and not Coke cans) I find that generic soda cans are less likely to have a coating on the inside that prevents effective corrosion which is needed for the battery to work. If you have to use cans with this coating, you'll need to remove the coating with sandpaper somehow first. I've heard of using hydrochloric acid, but I cannot safely recommend that here, so don't do that unless you know what you're doing and understand that it is strictly at your own risk!
- roughly a 6 feed length of 1/2 to 1 inch in diameter copper tubing or another equally substantial amount of copper with similar or greater surface area.
- approximately 4 feet of medium gauge wire that is between 10 and 20 gauge.
- Either solder or aligator clips can be used to fasten your wires to the battery's electrodes
- A decent pair of wire cutters and strippers.
- Water. Good old H2O or Plain tap water works fine.
- Bleach. Any kind will work, but I use the concentrated type for better results. I've heard using Clorox brand works better too, but I refused to buy a name brand bleach for testing.
- Salt. Regular table salt. You'll need several tablespoons or about 2 tablespoons for each cell at the most.
Those are the things I"ll be using for my first experiments and these items were selected based on my preliminary testing.
Putting it all together:
It's not really hard to build home made batteries, but it is time consuming because you have to produce several cells and run some parallel and some in a series until you get the voltage and amps required. Here are the basic steps:
- Take 1 of your 12 oz soda cans(you could use larger or smaller ones too) and clean it out.
- Measure your can from top to bottom and cut a lengh of copper tubing(or other copper material) to approximately 1 inch longer than the can.
- Wrap one end of the copper tubing with electrical tape so that when you stick it down in the pop can, it doesn't ground out to the bottom of the can(or make sure it just doesn't touch the bottom if you don't want to take it. Then place a mark on the copper tube where it meets with the top of the pop can.
- Fill the can with plain tap water from your sink.
- Using the mark you made on the copper tube from step 3, wrap enough electrical tape around the copper so that you can fit it firmly in the mouth of the pop can. It should be a little snug at least with the tape around the mark keeping the copper from touching the can at any point. It is important the the two metals never touch or your battery will never work!
- After inserting the copper tube into the can, solder or clip a 2 inch length of wire to the portion of the copper tubing that sticks out above the top of the can.
- Solder or clip another length of wire 2 inches or longer to the rim of the alluminum can. This will be your negative lead and the one on the copper will be positive.
- Hook your leads to a multimeter and record the voltage and amperage from the single cell bettery you have just completet. You should get about 1/2 volt and very little amperage.
- Continue to make a total of at least 6 cells by repeating all the above steps. Label each cell you have made from 1 to 6 or 1 to 8 etc., depending on how many you made.
- Connect the positive lead(from the copper tube) of cell one to the negative lead of cell 2. Then the pos lead from cell 2 to neg lead on cell 3......continue until all cells are wired together in a series.
- Measure the voltage from the negative terminal on cell one and the positive terminal of the last cell and you should have between 6 and 16 volts so far.
That's basically all there is to it, but now you will know if you need more cells in series or in parallel depending on if you need more voltage or amperage. Add more cells in series to increase voltage and in parallel to increase amps. Also increase the amount of bleach and/or salt in each cell to increase voltage, but remember that the stronger the solution is, the faster the battery terminals will corrode and eventually need maintenance and/or cleaning to keep them producing the optimal voltage and amperage needed.
Size of container
I've tried everything from Popsicle trays(like larger ice cube trays), aluminum cans and 5 gallon buckets. What is the difference in the size of the battery you ask? Surprisingly very little. Whether using a 5 gallon bucket with large electrodes and 5 gallons of electrolyte or using a pop can, both batteries produced roughly the same amount of voltage ranging from 0.4 to 1 volt depending on the strength of the electrolyte solution.
Electrolytes is the key to more volts within a single cell I discovered. While other factors can alter the amount of voltage only slightly, the strength of the electrolyte was the main factor that effected the amount of voltage the batteries Ive made so far produced.
To increase the overall voltage produced by your home made batteries, you need to increase the number of cells in the battery. A battery is often a series of several cells unless it is a single cell battery, but usually when I refer to "battery", I am speaking of the entire group of cells making up a single batter. A home made battery will often consist of 6 or more pop cans or other containers wired in a series or in parallel. To increase voltage we would run them in a series which means to attache the positive lead from the first cell to the negative lead of the second cell then continue until you reach the last cell. At that point the negative lead on cell one and the positive lead on the last cell will be open and those will be the two terminals used to power your device.
The key to more amps seems to be in the general size of the battery. I was able to product significant;y more amps using a five gallon bucket as opposed to a 12 oz soda can.
To increase overall amperage a battery produces, several cells are required just as with increasing voltage. To increase amperage however, we have to wire the cells in parallel instead of in a series because batteries wired in parallel will cause the amperage to increase and the voltage to remain the same. Often times batters consist of a combination of cells ran in a series and cells ran in parallel to product the desired volts and amps. The general idea we are using will be to wire enough cells in a series to get 12 volts in a single battery and after that we will increase the amperage by making several of these multi-cell/12 volt batteries and connecting them in parallel.
My First Battery
After testing large & small containers, a few different metals and several combinations of electrolytes, I ended up making my first batter with a series of 8 cells to product 12 volts at