2.5Watts?? Not sure that would be healthy, let alone legal! LOL
Can an E-Revo do 3 miles on a charge? Hmm. I'd say you could possibly do it with the standard chassis but it limits the size of batteries you can use. An after-market chassis would probably make it possible. You can see that, with mine, you could double-up on batteries by stacking them on top of each other and run them in parallel, so you're running 4S2P or 6S2P. This kind of battery would probably do the trick for a 6S set-up
Would be great for 4S...
OMG! That's 12.8Ah. That's like a decent sized car battery! A pair of those bloody things would get get you up the Matterhorn and down again! LOL
You could just about fit them in a standard E-Revo / Summit chassis but you'd need to hack it around a bit. If you need a spare to experiment with, I've got an old one I don't need.
I don't mind answering this kind of question. If there's anything you need to know, just let me know.