What do you guys think?

[florianz]

the fan does not cost relevant power. I think it's good that the fan is always on. I mean, who cares, when you're bashing you don't hear the fan.
you can go for 5000mah, but whith 6s you could even go with less, as you have less amps then in a similar 4-s situation.

you could test your 20s lipos, keep an eye on the temperature, and if they get ballooned. My cheap 20c Turnigy don't make any trouble at all. So before you throw them away, just have a try.