[Elecraft] Battery vs Ultracapacitor

[w8ur at flatsurface.com]

At 11:18 PM 6/27/2005, Kevin Rock wrote...
>If I have done this correctly you should be able to run a QRP rig key down for approximately 14 minutes with a fully charged 5K Farad ultracapacitor.

Discharge curves vary significantly between caps and batteries. Caps discharge exponentially, and the voltage would drop to an unusable level rather quickly. Chemical batteries have a much flatter discharge curve, and much more of the available power is therefore useful. More of the available power in a cap could be used with active voltage regulation (step-up), but that would bring further inefficiencies into play.


Mike Sauve
W8UR