On Thu, 26 Oct 2006 00:22:01 GMT, ml wrote:

I was thinking of getting a jado fuel cell, it puts out 100w (about
8amps ?) @12vdc

Hi Myles,

Fuel Cell??? That is a pretty pricey option.

More than likely it is 100WH (Watt-hour, not Watt) rated.

wanted to power a 2m rig at low power 5w out it falls w/in the spec's
of the jado but i wanted a buffer

Well, a 5W transmitter is not going to load it too heavily, but you
have to figure that 5W out is a 10W demand on the battery. This means
your battery will work 8 - 10 Hours continuous (you don't sit on the
key, do you?).

at first i thought of a battery using the full cell to charge the
battery during receive since tx is brief but how do i calculate

A battery - fuel cell - battery?

how big a battery i need?

At least 100WH, undoubtedly more.

Why charge a fuel cell with a battery? Why not cut out the middle man
and just run battery operation?

i also wondering if perhaps a capacitor or a few of them might also
do the trick and if so how to size them

Not unless you can assemble a couple hundred Farads (note the complete
absence of pico, nano, or micro in that Farads). The short version is
DON'T GO THERE.

73's
Richard Clark, KB7QHC