I run 5000mah 30c packs in my SV27s and that esc is rated to 45amps!!!!!!!!!!!!!
I'm about to buy 4s 4000mah 20c packs and run them in parallel to get longer runtimes and have double the amps!
the more amps the batteries can deliver the cooler the esc and motor will run, and also the batteries will last longer and take more charges becasue they are not being worked as hard