Power/Super Capacitors

[kevsta]

Hi,

Does anyone know if this:
http://www1.jaycar.com.au/productView.asp?ID=RU6700&CATID=&keywords=super+capacitor&SPECIAL=&form=KEYWORD&ProdCodeOnly=&Keyword1=&Keyword2=&pageNumber=&priceMin=&priceMax=&SUBCATID=

can be used for this:
http://www.rckenon.com/shop2/catalog/product_info.php?products_id=98

to achieve this:
http://www.schumacher.clara.net/powercap.htm

Thanks in advance,

K.

[kitsune]

Depends 🙂 (Okey I love giving non answers)

If your not going to be providing more than 5.5V from your batteries this should do the trick in a general sense, performance will vary depending on exactly what capacitors you use, Low ESR Caps give better performance, and you want to use a capacitor with the lowest voltage rating that is higher than you batteries kick out. given that the cap you’ve pointed out from Jaycar does not mention low esr and is designed to provide small amounts of power for a long period of time, I think you will get better performance from other capacitors, as for how many f,uf or pf you should use it varies to small and you’ll be getting less “punch” than you could get from a capacitor with more capacity, too big and your car will lose out on performance while the cap charges, the bigger the longer the charging time.

Capacitors don’t actually provide extra power, what they do is store some of the power from your battery and when your car is sucking more power than the battery can provide then the car also sucks some of the stored power from the capacitor, (if the capacitor wasn’t there the car would not accelerate so fast because it would be limited to the peak output of the battery, the capacitor increases the peak output of the battery at the cost of the sustained output of the battery.)

Hope this explanation makes sense.

I’ve had a hard time finding good caps with a voltage rating below 10V at Jaycar, then one day I saw that computer motherboards use 6.3V Caps 🙂
Guess who nicks them of the dead motherboards at my work (Working in a computer store has its perks).

Visit your local computer store, be nice, see if they can put aside some dead motherboards for you 🙂 cheap and at 6.3V probably better than a 5.5V if you’re seriously charging your batteries.

(Yeah I know NiMH say 1.2V but trust me when you charg them they can hold more than that 🙂

So back to the question yeah sort of but there are probably other caps that will do the job better, (If someone knows something about these 5.5V caps that I don’t please let me know, but IMHO Low ESR 6.3V caps may be a better chioce)

(And if you’re using 7.2V forget the 6.3s and go to the 10V ones 🙂

[SausaGe_LinK]

Its all about the Internal resistance of the capacitor(ESR). If you are just using a normal all purpose capacitor not suited to high current applications then u might as well add a paper weight to your car. But if you get a good Low ESR capacitor then it can make a significant difference.

Jaycar actaully sell low ESR capacitors. I went into the springvale store but i couldnt find them in the components section.

[kitsune]

See page 56 of the new catalog, 🙂 but be warned just because it’s in the catalog does not mean they stock it yet. I’m still waiting for some surface mount fets, they should be in in another month 🙁 Ask them if they have them in, and if not can they give you an eta?

RE-6308 looks to be the closest fit,
$1.66 4700uf 10V
RE-6306 might do the trick too
$1.02 2200uf 10V

or if space is really important SMD might be more compact (I havn’t measured tho.)
Pack of 10
RE-5912 470uf 10V
(Join all 10 in parallel to get a ~4700uf 10V Cap)

[SausaGe_LinK]

Yeah i should have added. They arnt in stock yet 😀 Been in twice since i found them on the website and couldnt find them.

[jamiekulhanek]

Those supercaps have an ESR of around 30 ohms, which is fukin heaps….

In short they are designed to run a pc clock, not a high current motor.

As sausage link said, its like sticking a paperweight to your car.

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