Super Capacitor operation with internal resistance (ESR)

[BrianE22]

When looking at charge and discharge rates for capacitors (super caps in this case), can you model the device as a perfect capacitor with an external resistor equal to the ESR value? Also, I notice that some vendors list a maximum operating current for their super capacitors and others do not. I assume trying to pull current out of them too fast can harm the capacitor. When you're not given a maximum on the specification sheet what would you limit the current to?

 

[zappedagain]

Yes, a resistor and a cap is a valid model. Just watch that the datasheet probably has some margin o the worst case ESR, so it will probably be lower and may vary with temperature.

Imax = Charged voltage / ESR

Z

 

[itsmoked]

I believe it's not so much a damage issue as a charge transport issue such that you can't get the charge back out any faster than what's stated. Hence, some companies not listing it as it isn't a damage issue. (but I'm guessing here)

It's all here (including how to model them):
[URL unfurl="true"]http://www.tecategroup.com/ultracapacitors-supercapacitors/ultracapacitor-FAQ.php[/url]

Keith Cress
kcress -

http://www.flaminsystems.com