Not seen the video, does it have springs either end to ‘bounce’ the magnet back at the end of each pass?
Well, you have not really re-invented anything, I have a 15 year old plastic torch that has the exact same internals with 5mm led, a shaking magnet and inductor. It just has no supercap but that is not new either in this concept.
I like the nice design and I like the use of a supercap but would be happier if it did not have the li-po battery.
10 seconds shaking for a minute of light is pretty annoying but in a situation without batteries (i.e. zombie acopalyps) it should be usable.
If the zombie apocalypse is not happening however, a small 20 lumen flashlight with one AA battery will save you 6.5 hours of continuus shaking.
Still the concept is appealing.
All of the energy must come from the kinetic energy of your arm as you shake the light. That was the whole point of the article. There is no free energy for your device.
I think people underestimate just how much energy is in a simple battery, and how inefficient it is to do physical work to power something.
For example, a basic AA battery has about 2.5Wh of energy, or 9000 joules. That amount of energy is capable of lifting a 154 pound man (70kg or 686N) 43 feet into the air (13.1 meters). That’s like climbing up a ladder to the 5th floor of a building.
Trying to shake your wrist to lift yourself up 43 feet would take a huge amount of time. Like, well over 10,000 shakes!
I’m not bashing your project, just trying to put a realistic take on it. You haven’t “reinvented [the] classical principle of electroinductive charging”. You’re just converting a arm’s kinetic energy into electrical energy, and that takes a lot of work.
Sounds like the old shaker torches that never caught on.
Perhaps because so many were fakes, with just a primary coin cell and the coil, springs and magnet did nothing. The real ones did work though, usually with a NimH cell (before Liion and supercaps became available or affordable).
TBH, a crank wound torch is a far better solution than waving your hand around, I have three modern ones for emergencies and they are quite good at converting minutes of winding time into many times more minutes of light.
One of these might have been a comfort to the “Wild Boars” during their ordeal.
Though they are all cheaply made, I wouldn’t trust the gearboxes to last.
What is the unique selling point of this torch ?
PS: the supercap is a bad idea, an LED needs a well defined voltage to work consistently, a capacitor, whilst storing energy, has an exponential voltage decay. So unless it’s being charged to well above LED Vf, then dropped down to the LED through an efficient buck driver, I’d say it is a non starter.
Read the post.
The supercapacitor is short term energy storage, which then charges a lithium battery which then most likely drives the LED through some regulator.
Still, these shake-to-charge flashlights have been around for decades and as you said, never really caught on.
Not gonna spend a whole minute shaking a light, at most I spend 10 seconds to plug in a flashlight through USB in order to get several hours of runtime.
Also, 20 lumens is far too little, a few hundred is the minimum usable for most people, while 1000+ is almost standard.
Yes, cranks are more efficient. But, still very inefficient. I have an emergency radio that has both a crank and a small solar panel that can charge the internal battery. The manual states it takes 8 hours of cranking, or 3 hours of sunlight to charge. Guess which method I use? 
I think the idea is that the supercap is used to capture the burst of energy from a shake, then the battery is constantly charged from the supercap. Given how long it would take to charge the battery from shaking, I imagine you could charge the battery directly if it wasn’t for the pulsed energy from shaking. Using a crank, for example, you can charge the battery directly because it’s constant power.
Yes, to make shaking easier.
Sure, I haven’t invented anything new (and guys, come on! I’ve mentioned Michael Faraday on a project page )
What are key benefits of my project in comparison with old plastic chinese flashlights? GOOD MATERIALS!
And I mean high quality internal components, ultra thin wire to have 3500 coil turn, diod bridge on schottky diodes, N45 rare-earth magnet. Everything I’ve wrote about are expensive components. I guess a magnet alone costs more then chinese flashlight itself.
Heh, imagine how much shaking you’d have to do to charge up a decent 1000 lumen light! You’d shake yourself to death, first.
Sometimes it’s bad to be honest Ok 20 Ansi lumens or 100000 Chineze lumens
Well, if the shaking action is similar, it could be easily used by the male population, and provide an ECO alternative to onanism.
I’m not knocking this, if it is done well and efficiently, reliably and durably I am interested. Just one moving part is very attractive.
Make it totally waterproof to a good depth (laser welded, or bonded) with a magnet/reed switch, totally durable and shock proof and I’ll be tempted
Nonsense, I was able to lead a group of 7 mountain bikers home in pitch blackness with one 18 lumen Petzl headlight. My first maglite was a AAA solitaire with 2 lumen output, in candle mode it could light up a whole room once your eyes were properly adjusted.
Agreed Zulumoose. 20 lumens is lots.
Now here is a war story, years ago I was out with my ski club (actually my sailing club, we did this every year), last day, we had booked an evening at the top mountain hut after the lifts closed. A fondue evening, to be followed by a run back holding flaming torches. 1.5 Km down, 7Km distance. Red and black.
Then the proprietor offered around his home made schnapps. So we imbibed (would have been rude not to).
By the time we left it was past midnight, we were all inebriated, a storm had blown up, the flaming torches blew out instantly. So we had a discussion. The decision was to go off-piste, directly down, 2.5 Km. the snow crust had frozen hard so we thought even those without powder skis could do it.
I was the only one with a decent head torch, so I lead from behind. Our guide led from the front, she had double ended skis and could do a black run backwards faster than any of us forwards, as for the snowpark…)
So we got all of us back with just my crappy head torch, a “1W” led powered by three duracells.
And the sweeper-up on the snowmobile (we did do some risk assessment) didn’t have to work, nevermind calling in a piste basher to take more down.
So, hundreds, or thousands, of lumens are an extravagance. Keep it real and let your eyes work.
Looks interesting if it does require minimum shaking and the size is about right.
I still have 2 of the original Shake Lights from I’m guessing around 20 years ago. They were quality built but required too much shaking for the minimal light they produce. They were around $40.00 back then and I got the pair for next to nothing as people who originally paid the big bucks found out fast they were more hype than anything and let them go for cheap.
They did spawn a slew of imitators that were cheaper but were absolute junk. Guess I’ve kept these around in case the apocalypse comes to fruition.
Good luck with your project.
P.S. These original Shake Lights are good for arm exercise!
20 years ago Ferrite magnets were used. And now we have neodymium that are 15-20 times stronger in the same size. That’s the main difference.
I agree . When its really dark a little goes a long way . Demonstrated that in a cave once or twice. A Skillhunt on low was all I needed
20 lumens would also be easy to get from a regular AAA battery, or rechargeables + tiny solar charger.
Hmm, reminds me of this device…
This seems to be an exciting concept.
Imagine scaling it up. Get light, and get exercise, too.
Wle, and what if zombie is at the doorstep and your solar charged flashlight was layin on the dark shelf? 
Here’s an idea, make an inductive docking station to charge it up usually. You have the coil already, it just needs another one in the dock, like an electric toothbrush.
Like the emergency torches that you can buy already. Some of them switch on automatically if the mains power goes.
Interesting project indeed.
One thing i’m worried about is i’ll never use it… unless i ran out of every other possible light source, including a lighter or matches. And then, years after, i fear the Li-Po battery will be dead from aging when i finally need it. How long will the battery last unused? In most situations i’d rather carry a couple AA lights and spare batteries rather then this somewhat big light.
Still, if i was stuck in a remote cabin for days and was out of every other power source, i’d be glad to have it.
Eternal flashlight? Will it be serviceable to change parts or upgrade it?
Considering this shake-me light dimension i’m sure some 3D printed add-on/sleeve could easily turn it into an eco adult toy… Love is energy! :heart_eyes: Don’t forget to remove the add-on before going out with your light during a blackout though… :person_facepalming: