Cheap handcrank lights

I see a lot of people raving about hand crank lights. ‘Crank a few times and when I turn the light on, it will burn of hours’. That is simply not true. A good hand crank light, should have a build in capacitor or battery which will store the energy which has been generated. But this will generally not last more than 15 – 30 minutes, not hours. There is only so much power your arms can produce in a short period of time. Let have  a look at internals of this light and see what we find.

When you take this light apart, you will actually find working sprockets, a free wheelie and a little dynamo connected to the LED. These are connected directly to the LED and are not actually charging anything. So all the light being produced while cranking this light, is the only light you are creating when cranking. 

The switch on top of the light is the switch for the battery part of the light. There are two CR2032 (non-rechargeable) batteries, wired to the LED and the little switch. This makes up for a separate power circuit in the light to battery drive the light. 

The crank part of this light is not really impressive and will drive you nuts when the batteries have gone flat. But at least it does have a working crank system. There are even fake crank (or shake) lights, which doesn’t have a working system at all and only contain a little battery. Which means they are very large and heavy button cell lights. Just like anything else, there are no cheap ways to deal with this. Either buy a proper (expensive) one and crank/shake a lot or just get a proper battery powered one and store plenty of batteries.