[Elecraft] Battery vs Ultracapacitor

[Kevin Rock]

I've been reading the technical literature lately and have been following 
an interesting development: ultracapacitors.  These components are on the 
order of 5K to 20K Farads.  So I did a little calculating.

1F = 1V * 1 Coulomb.
1 Coulomb = 1 Ampere Second
Thus 1F = 1V * 1 Amp Second.

5000 F / 12 V = 416 2/3 Amp Seconds.
416 2/3 Amp Seconds / 0.5 A = 833 seconds or 13.8 minutes.

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.  From what I have been reading these are getting cheaper 
via economies of scale and from engineering breakthroughs in dielectric 
and storage plate materials.  The storage plates are activated charcoal 
plated on aluminum strips and wound into a can filled with electrolyte.  
The electrolyte material, acetonitrile, is the rub however.  If it burns 
cyanide gas is produced in dangerous quantities.  Nanotube technology and 
more recent electrolyte chemisty advances are offering even greater 
capacitance in smaller packages.

One day we may be running our rigs from ultracapacitors instead of 
batteries.  They recharge extremely rapidly.  They store charge for a long 
period of time.  And they discharge at rates that put the best batteries 
to shame.  If you need high amperage devices (think your 100 watt rig on 
transmit) these will fill the bill.

Since electrochemical devices are reaching their limits this may be the 
next mobile power storage device.
    Kevin.  KD5ONS


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