Yes! Use 3- or 8-watt-hour magnets as a starting point for a small-scale electrical system. The idea is to charge a battery or to discharge it. These are all good things to do on the go, but don’t use more than 2-watt-hour-per-magnet (or your battery isn’t ready for this).
A good battery
Most people start with a battery they buy for their car, but there are plenty of alternatives out there. Most people buy rechargeable batteries, but as with all batteries, they can have a few defects and their performance can be unreliable. They also use batteries that hold a lot of juice. One option is to buy a “rechargeable” battery, like a AA or C battery. These rechargeable batteries have a smaller charge capacity than AA, but can be recharged for a day, or even a week if charged properly. These are ideal if you travel a lot, like in a bus or train, or for other emergencies.
These batteries come in different sizes and they can usually be connected to a charger using a plug. Some manufacturers, like Duracell, make one of these rechargeable devices that are available in various sizes. However, they are less popular than the rechargeable batteries that come in packs with different sizes or shapes or lengths of cables.
One way to make your own battery, and keep the cost down, is to buy an inexpensive battery to take with you, like the 12-volt version of a cellphone battery, which you can buy from Target for $2 for 60 minutes to three weeks, depending on how old and worn out it is. You can also buy rechargeable batteries that are available from online retailers for less. These batteries won’t have the same long shelf life as rechargeables do, but they last much longer. You’ll probably want to replace them often, too, to keep the battery good for years. You can also buy rechargeable cellphones and other electronics, but you’ll have to replace them yourself. Some of the cheaper electronics are rechargeable, but not all!
You can make your own battery using a battery to do many jobs. As a start, you can add electrolytes (like water, ammonia or glucose) to the current that flows through electrodes (in the battery compartment). The result is electricity with a chemical bond between two metal electrodes, which is sometimes called an “ionic” battery. That’s fine for short range, but it