LukaQ,
It's $11 at mouser, I just got a few to experiment with: https://www.mouser.com/ProductDetail/581-SCCY68B407SSBLE
Where do you get the 1mA discharge? Isn't that directly proportional to the ESR, which at 1.8mOhm is the lowest I've seen in supercaps?
200F is not a lot in terms of mAh, there's a formula to calculate it, it comes to a few hundred mAh.
Short answer:
With a 1 volt change in output voltage (for example if you charge it to 5 volts and your circuit works when the voltage drops to 4 volts), a 1 Farad capacitor will give 277 microamp-hours.
The relationship is linear. 10 Farads gets you 2.77 milliamp-hours, etc.
so, if I have 12.5F and I can have 1.7v drop from 5v to 3.3v, that gives me about 5.8mAh. Compared to 1000mAh of batterys...
Even yours "only" come to 94mAh.
Equation from datasheet is 0.5*C*v^2*1000/3600 = mWh
I guess question here is, what is your device consumption over time. With a lot of sleep, that goes down to or below 1mAh
And yes, here are differences in caps: my has 28uA leakage current, if I would scale that up to 400F, that would be below 450uA, less than half of one of yours. Dave Jones would say, you are pissing power away
While true, you can charge supercaps faster, just about no one would give more than 1-2w solar cell on it, that is still low IMO
Without testing, I'm just not sure, how long would moteino/sensor run before power would need to be put in (charge supercap)