When your phone’s screen begins to flicker and die or your torch grows dim I bet you wish for one of these – something which will keep them charged forever. It outputs around half an amp (at 5 Volts) at the recommended 1 rpm ie 2.5 Milliamp hours/watts (per hour) – enough to charge your phone battery anyway with just that bit of effort at the end of the day.
This is about the same as the (best) Buheshui 10 watt solar panel I wrote about which only works though when the sun is shining ie not at the end of a hard day’s hiking wen you need it. The solar panel is lighter at 140 grams than this hand generator which weighs 269 grams.
BTW I have hooked two of these solar panels to the same usb output (with the appropriate connectors so that the output is doubled) bringing them to about the same weight as the dynamo but again they only work (though effortlessly) when the sun is shining. On a really bright day I have managed over an amp (nearly 1.5 actually out of the two of them connected together).
Note also you can double the output of your solar panel with a Tyvek Solar Reflector.
Warning: I have noticed though that if you are charging eg (Nitecore NB20000) power banks (as I was) that as the sun warms them up they obviously have a circuit in them which shuts them down so that they won’t accept any more charge – just when you would otherwise be getting the most current out of them!
This did not happen with my cheap or free power banks probably because they have 18650 batteries inside them.
This also does not happen with the hand generator. Important factors to bear in mind before you spend you hard-earned or head out into the backcountry.
The dynamo has capacitors in it which store some power enough anyway to run a quite bright led light by itself. This is a handy feature.
The hand generator will not be enough to recharge drone batteries at the nd of the day unless I want to spend many hours cranking. Back to the drawing board for that particular project.
I bought mine from Aliexpress for A$24 (Mar 2026).
I have had lighter and more fragile ones which did not work nearly so well and were insufficiently robust for enduring field work. This one s solidly built and should last.
See Also:
