What is the approximate equivalent of 1 hour of playing time in mAH for a Playstaion 2 Slim using a generic PSone screen.

I am thinking about using a 4200 mAH battery instead of a 5000+ one to save money, but I don't know if that is good enough.

Check out this topic:

http://forums.benheck.com/viewtopic.php?t=25867

From what it looks like you are looking a little bit over 1 hour. You should really consider if you want batteries or save space and money and do not use batteries.

I want it to be "wireless", but I guess I'd save a lot of money not using one.

So are you suggesting just make a portable which you plug into the ac wall adapter?

Yep. A decent 4000-5000mAh battery @ 7.4V can cost about 49.99 and up. The charger is about 22.99 (Quoting batteryspace.com prices).

PS2 needs 8.5V from that post I gave you. I do not know if 7.4V is sufficient for PS2 slim.

If you are ok with a little over 1 hour of gameplay with that setup you asked, then go for it.

If you want to save money, just run it on AC power.

The choice is yours

Thanks lex.