This is a simple insructable which will graphically demonstrate how to wire multiple power sources together to get the voltage and current you need for your project.
You will see that this demo uses a couple of my Al/Air fuel cells but you should be able to use any power sources you like.
It is not required that all the power sources be the same and this can affect your output. For instance wiring 3V and 9V batteries in series will give you 12V
Step 1: Bill of Materials
In this example we will be wiring together two aluminum air batteries so we'll need a couple of batteries and some leads for interconnecting them.
A multimeter for measuring voltage and current also comes in handy.
Other power sources that can be used include battery packs, wall warts ( two 9V warts = 1 18V ) or just about anything else.
Step 2: Wiring Two Batteries in Series
First we measure the voltage from each battery. Then we wire them in series by connecting the negative lead (connected to aluminum foil) to the positive lead of the other battery.
Here we can see that two batteries, one with 850 mV and one with 774 mV produce 1.568 when wired in series. As you can see we lose a tiny bit of power in this circuit ( approximately .05 mV ) most likely due to the nature of the connections.
Now let's take a look and see what happens when we wire them in parallel...
Step 3: Wiring Two Batteries in Parallel
Unlike wiring batteries in series when batteries are wired in parallel the voltage does not increase, the output voltage is the average voltage of all batteries in the circuit. For example if a 3V and a 9V battery were wired in parallel the output voltage would be 6V ( 9+3 divided by 2 ) however the current will be total amperage of all batteries in the circuit (minus any losses).
In this case we can see that 89.6 muA and 70.6 muA produced a collective current of 138.4 muA or about 21.6 muA below our expect 160 muA. This is accounted for by losses in the circuit.
Step 4: More Power - Series Wired in Parallel for Maximum Duration
Step 5: Maximum Power - Wired in Series and Parallel for Maximum Power
This configuration shows the batteries wired together using both serial and parallel connections. This will maximize the voltage and the current.