Sunday, June 19, 2011

What should I build with six ultracapacitors?

I bought six 2600F 2.5V ultracapacitors from Electronic Goldmine. They were on sale a couple weeks ago, and this was one of my rare impulse purchases. I am thinking of building a portable capacitive discharge welder, or perhaps conventional spot welder. What are your ideas?

17 comments:

  1. Definitely a spot welder. Rebuilding battery packs by soldering tabs often ruins the cells, so a DIY battery spotwelder tutorial would be awesome.

    ReplyDelete
  2. I'm voting for a spot welder also. I've been wanting to build one for a while for doing stainless. A nice build + parts list would be awesome.

    PS: Love your site and the stuff you are working on.

    ReplyDelete
  3. Coil gun or some explosives thingy...

    ReplyDelete
  4. They are still on sale until tomorrow and work out to $8 a piece!!

    ReplyDelete
  5. Two Words... "Quarter Shrinker"

    http://www.capturedlightning.com/frames/shrinker.html

    ReplyDelete
  6. How about a seam welder? A fair bit more work than a spot welder, I know. But you've got the Grizzly to pull it off to a high standard :)

    ReplyDelete
  7. I would go with a capacitor-gun. Use a high powered laser to ionize a path to your target and see how far you can aim the thing. Would be interested to know the logistics of over-the-counter IC weaponry...

    ReplyDelete
  8. some peeps from my lab bought a couple dozen or so of the same caps, I believe they intend to use them in an EV.

    ReplyDelete
  9. Spot welder or a seam welder, never know when you'll need one of those!

    ReplyDelete
  10. If I'm not mistaken, ultracapacitors will not discharge completely super fast like normal capacitors will... so many of these suggestions are moot. Watch some videos of them being discharged on you tube, they will heat a wire red hot for quite a while instead of vaporizing it in a flash like standard capacitors.

    However they will charge up more quickly and efficiently than a lead acid battery... Which is why they are used in regenerative breaking, they take the charge from the breaking generators and then use it to charge the normal storage batteries back up at a slower more efficient rate that the storage batts can handle... with 6*2.5v you have ~15v... which is higher than the voltage of a standard car battery at 13.8... if I'm not mistaken... so perhaps you could hook them up to your car battery in such a way that they help provide a little extra amperage for the spark plugs while also charging up faster than the lead-acid battery. So long as the string of ultra caps isn't charged beyond 15v, they should be ok... though I'm not sure what sort of precautions you would need to take when hooking it all up and using it, I dunno if you would need a balancing circuit for the caps or anything.

    End result could be a little bit more efficient charging of the lead acid battery (very slightly less energy wasted as heat) and a little more weight... would it give a measurable net boost to MPG or not? Dunno.

    Perhaps you could use something like this:
    http://www.perfectswitch.com/power-gate/battery-discharge-controllers/single-rectifier-isolator/

    Though total Ah capacity of a 6*2600F array of ultracaps would still be pretty low... so its essentially a specialized battery which can charge up faster and more efficiently than a normal battery, millions of cycles without significant degradation, unlike normal batteries... can be left in any state of charge without damage unlike normal batteries... and can discharge pretty fast, though not as fast as normal capacitors... but it has a crappy storage capacity... So calling it an auxiliary battery is kinda weird.

    I dunno. Hope this gives you some ideas.

    ReplyDelete
  11. Ultracapacitors are used in the 5.11 Light for Life LED flashlight to allow it to charge up quickly and be recharged an extremely high number of times without significant degradation... So perhaps there is a possible project there...

    A portable medium/high power (depending on your definition of high power) LED flood work light for instance. You would want to use a constant current LED driver which has a very wide useable voltage rating to get the most benefit from the ultracaps. Or use a DC-DC converter, then a constant current power supply. 2 of the ultracaps would be 5v. So something like this could be useful to allow you to drain the most from the ultracaps:
    http://www.dimensionengineering.com/lvboost.htm
    For efficiency you would want to run something like Cree XP-G or XM-L LEDs.

    If you have any frequently used power tools I wonder if you could adapt them to plug into an external corded ultracapacitor bank with appropriate voltage booster to keep the voltage where it should be for the power tool.

    In either of these possible projects, you would want to design a charger circuit that would quickly charge up the ultracaps much like the fast charger for the 5.11 light for life that charges in something like IIRC 90 seconds.

    ReplyDelete
  12. Did you get around to using it for anything?

    I really regret not getting a bunch of these ultracaps when electronic goldmine was selling them.

    ReplyDelete
  13. Coin shrinking!!

    http://205.243.100.155/frames/shrinkergallery.html

    ReplyDelete
  14. Apparently they can discharge at 600 amps, perhaps you could rig up 1 cell to an array of 2.5 v laser diodes with a total current rating in excess of 600 amps and call it a laser gun.

    ReplyDelete
  15. If I had those capacitors I'd buy a small LiFePO4 battery and with that bank replace the LA battery in my car. The battery would last nearly forever and the cap bank would supply the needed 200A starting current and I'd never have to replace my car battery again!

    ReplyDelete