Low Leakage Current Supercapacitor suggestsions for PZT energy harvester?

[mark12]

Low Leakage Current Supercapacitor suggestions for PZT energy harvester?

Hi All,

I've run into this site every now and then and you all seem very helpful, so I thought I'd make an account.

I'm working on a Low Power PZT Energy harvester and have been searching for supercapacitors to be used for energy storage. Because of the project's power limitations, I've been trying to look for a good quality supercapacitor with very low leakage current and ESR.

I was wondering if you had any suggestions for a particular supercapacitor that has worked well for you. I'm hoping to find 5 or so possibilities and test them to see which one performs the best since leakage current is such a big issue with this project. I'd also like to hear your experiences if you've run into similar situations!


Thanks!

 

[dick_freebird]

I would bet that the supercap matters less than the efficiency
/ effectiveness of transferring the piezo charge blips into it.

A bigger cap will leak more. You probably want to work back
from hang time and stuff like that, know your needs and then
pick from the options.

Are you sure a small bettery wouldn't be better? Supercap
will swing across a wide voltage range and then needs a
post-regulator - generally inefficient at low power. A
battery is perhaps "self-regulating enough" and can just
be charge pumped without much care if the input current
is low. Compare functional density and self-discharge (plus
discharge attributes of charge and power management
circuitry you will attach) and you may decide you are
better off with another storage. Like a NiMH coin cell or
something. There are a lot of non-mainstream battery
technologies out there with unusual attributes.