LED Flashlight with Super capacitor 150 F 5.4 volts

[dinoth]

My old battery died and I replaced it with super capacitor.
Charging with USB 5 Volts
Here is the video.
http://www.youtube.com/watch?v=fXzX3Zc6Q1k

[magpwr]

Hi,

If 300F cap then my guess is run time for full brightness is below 30min with these many leds.

Do take note usb port output is only 500mA unless your using USB 3.0 around 1A output.
Plugging 300F cap 2 in series may kill USB port,USB chipset on mainboard for good.I lost a USB port on old mainboard before.

I find charging 50FARAD using 1AA battery(Zinc-carbon) is already taking couple of minutes not to mention 300F.

[dinoth]

I will modify it to last longer. Full brightness is ~20 min. I have 2.1A USB charger from IPad. With 5.2V on output, works great.
Do you have any suggestion for joule thief to extend "lifetime"?
My next project will be to modify small flashlight that have only 1 led with 2 120F caps.

Tnx for warning about USB ports. Happy new year!

[TinselKoala]

Yes, absolutely. I would suggest putting the caps back in parallel, operating between 1 and 2 volts or so, and using the basic 2n2222a JT circuit with a variable base resistor. You will have slightly less bright lights and greatly increased runtime. If you start fiddling with various JT variants you will be amazed at how long you can run on your big capacitors, but the basic JT will be a good start.

[totoalas]

Better yet recycle your old solar calculator cells and placed on the side of the front glass .
Use this with the 1 AA phone charger output is 5 v dc to your caps
totoalas