How to Make a Magnetic Induction Battery Charger

Last Updated: March 7, 2019

Electromagnetic induction is how most electrical power is generated. A rotating or moving magnet inside a coil of uninsulated wiring causes electrons to move through the wire, creating electricity. This is how to build a battery charger from such a property.

Steps

1
Get some rechargeable batteries. Non rechargeable batteries will explode if charged.
2
Go to an electronics hobby store and buy the following items:
- Battery holder for the type you wish to charge
- Electrical Wiring, preferable uninsulated, but if it isn't you need to strip the insulation off.
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3
Now you will need to acquire these mechanical parts.
- A hand crank
- Something to mount the hand crank to, but make sure it can still rotate.
- A bar magnet
4
Next you need to create a tube of wiring around the bar magnet. Make sure the bar magnet can rotate within the wire, but the wire is not more than 1 and inch from the magnet. Remember the magnet will be rotating horizontally, not vertically.
5
Connect the two free ends of the wiring to the battery holder.
6
Take a screw that the magnet wants to stick to and attach it to the hand crank.
7
Attach the magnet, using its own magnetism, to the screw. You may need two screws, one for each pole of the magnet.
8
Attach the crank onto the support structure so it can be cranked.
9
Place and secure the wire tube around the bar magnet.
10
Insert a battery.
11
Crank the handle to charge your battery.

Community Q&A

Question

If I connect two rechargeable uncharged batteries with two charged batteries, will they get charged?

Community Answer

Kind of, but it's not the way to do it. Imagine you've got a cup full of water and an empty cup of water. If you put them together, you'll have two cups half full of water, but still have only the same amount of water. The same thing will happen with the batteries -- you'll end up with one emptier and the other one fuller but still have the same amount of energy combined (actually slightly less as charging isn't 100% efficient).

Warnings

Non rechargeable batteries can explode when recharged.

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With any electricity, there is always some risk of electrocution. However, because the voltage and amperage is so low in projects such as this, the risk is so small as to be considered non-existent. You have a better chance of winning the Power Ball lottery jackpot two drawings in a row than being directly electrocuted with a project like this. However, if you have been directly electrocuted before by merely holding a watch battery or a AA battery, then you may wish to avoid this project.

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