This is really not difficult and only a few simple components are needed.
Step 1: Making Cardboard Circles
First of all, prepare the details for your future hand-made battery. Use vinegar mixed with salt to clean coins (they'll really look as bright as brand new). Leave them in the liquid for a while after you've cleaned them. Meanwhile cut 8-10 cardboard circles the same size as your coins.
Step 2: Making Foil Circles
Also, make circles from folded foil the same size as your coins.
Step 3: Assembling the Battery
So, after you have prepared all the details, you can assemble your battery. Put the details one one another in the following order: a coin, a cardboard circle, a foil circle. Do it until all the details are used. On the top of your battery should be a coin.
Step 4: Test With Multimeter
Measure voltage on the battery with multimeter, if you have it.
Step 5: It's Done!
Attach with sticky tape two wires to your battery: one on its top, another to its bottom. You also should wrap up your battery with a sticky tape. Fix metal terminals to free wire ends.
And it's done!
As you can see, it's not a big deal to assemble a simple battery by your own hands. You don't need special skills or materials to make such a useful thing.
Right now get some more tricks and lifehacks about batteries of all types on free online workshop How To Become a Battery Reconditioning Expert in 5 Steps.