Re: Cannibalizing Computers
If repurposing the power supplies, remember that they likely put out 12.0 volts, not 13-14 volts. This might be fine for powering things that only run when the generator is running. Do not connect a battery in parallel with an unmodified computer supply and the load, it will not charge the battery, but will let it draw down to 12.0 volts, which is about 50% discharged. I have seen at least one article on hacking spare supplies to power DC electronics, and some models were hacked by the author more successfully than others.
Also, the 300 watt rating is the combined power of all the +12, +5, and -12 volt outputs. Don't just divide 300 by 12 to estimate the DC amps available, look for the rating plate instead.
I haven't checked the power draw of computer fans, but I am also of the impression that they use electricity more sparingly than other types of air movers.
Someone said "Making good decisions comes from experience, experience comes from bad decisions." I say there are three kinds of people: those who learn from their mistakes, those who learn from the mistakes of others, and those who never learn.