This is what I've got

• 1 12v 0.2 amp computer fan
• 1 12v 0.16 amp computer fan

And a couple of phones chargers

• 1: 5.5V 0.2 Amp
• 2: 4.75V 0.55 Amp
• 1: 5v 0.35 amp
• 1: 5v 0.4 amp
• 1: 5v 0.750 amp

I can't find a direct answer on the internet, the closest I've got was [this][1]

I know that I can connect a couple of them in series and get 10 volts (which is fair enough) I'm just afraid about overheating the charges, or even melting the wires, any of them are as thick as an USB.


Is it safe to connect them to power the fans?

[1]: http://www.batterytender.com/connecting-chargers

 

Nobody can tell from here whether the outputs are isolated from the inputs. If they are isolated, it will work. If they aren't, the magic smoke will get out. Do you know how to measure them to see if they are isolated?

If they have isolated outputs, you can try a couple of power supplies that can produce at least 0.36 amps. The 4th one and the 5th one.

 

Welcome to AAC!

If the chargers have isolated outputs, you might be able to connect them in series. But most of them seem fairly wimpy.

The fans might work at 10V, and they might not. Why not just buy a 12V wall wart?

 

Instead of messing around with the phone chargers, go to your nearest thrift store or a Goodwill store and look through their stock of wall warts. Undoubtedly they'll have a plethora of them. Find a 12 volt one that will work for you. Our local thrift store has a basket full at $1.00 each.
Bob's your uncle.