General > General Technical Chat
Upper-class vs peon capacitors
(1/1)
PlainName:
Just looking around at supercaps for potential use (currently using battery to hold a system up for around 10-20 seconds) and I am seeing a range of prices (there's a surprise). For nominal 5V/1.5F good examples of the ranges are the RS Pro @ 95p each at 5-off:
and the Eaton Bussmann @ £7.99 each:
The RS jobby has worse tolerance but, other than that, what might be justifying the price difference?
T3sl4co1l:
Imagine you can find cheaper than brand-name of the low-ESR kind too, but that's the likely main difference between the two kinds shown. The coin type are, AFAIK, more traditional construction with high ESR, suitable for CMOS backup over some hours/days/months, and essentially no real power draw (ESR >kohms).
What ESR do you need? For a 20 second time constant I would guess the latter type, that's quite a lot of current draw to discharge a farad at, as backup capacitors go.
Tim
wraper:
First supercap is only good for tiny current due to very large ESR. Also it's produced by little known Shandong Goldencell Electronics Technology http://www.goldencellbattery.com/, but even that is not guaranteed since RS can change the supplier at any time.
PlainName:
Ah, thanks! I missed the ESR...
Navigation
[0] Message Index
Go to full version