I like supercapacitors. I think they are cool and I wanted to try to use one as a battery that I could recharge in seconds. I also like the challenge of using as little power as I can. So a while back I ordered some supercapacitors from digi-key to play with.
Powering a Microcontroller
The first thing I did was plug them up to a bread board and get them charged. Then I hooked one up to power an ATTiny85. It worked like a charm and ran a rather long time for a supercap. It was a simple Halloween flickering light thing. Unfortunately I don’t have any pics to post on here. But the proof of concept works. I bet lots of small microcontrollers could run off supercapacitors!
Then I decided I wanted to try keeping it charged with solar and make a little key-chain light. So I found some mini solar cells and got 10 of them to make 5 volts. Then a little signal diode to prevent discharge back into the solar cells and made this little thing.
It’s bright enough to use as a flash light to get around in a dark house in the case of a power outage or something. It also last about 10mins. So that’s not bad when using a capacitor as a battery.
Here you can see the back side with the 5.5 volt 1 farad capacitor.
I still need to clean it up and maybe 3D print a case for it. Then I could make it into a key chain.
I don’t know how practical it is. It might be good for unlocking your door at night. But it was a fun little project. Capacitors charge fast so I bet the solar cells will keep it ready to go all the time. So far I just leave it on my desk and it’s always charged when I turn it on.