-> Funny you should mention that,  as I did see that in a magazine a while back. 
-> The machine in question got something like 20 hours of runtime on it,  compared
-> to 3-4 hours on a standard battery.

Fuel Cell technology is Increadabily expensice at the present time.
Coleman, The lantern People makes a Hydrogen powered fuel cell Power
pack as I rembember it was $5000 for a 3 KW unit and iyt used special
exchange cartridges for the Hydrogen at some $125 for several hours run
time. You could of course hook up for an External Hydrogen tank but they
speckes a Very High Purity Hydrogen. And the stuff you get from the
welding supply house for HeliArc is way to dirty and could danage the
unit




->  TW> For the outdoor types there are special Solar Cell arrays also
->  TW> avaiable. But when the sun goes down you need to wind up yuor work.
->  TW> :-) :-)

-> What,  you can run one off one of those but it won't charge the onboard
-> battery?

 Depending on the Panel you can get some charging of the battery. Again
we have a comprimise between Size/Weight and how much above operating
the Laptop the Solar Panel can do as far as charging goes.
 You got me on that one, YES you can run after dark until the batteries
shut you down.

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