RE: what is a cheap f3a 5S 5000mah battery
I have non-nano Turnigy 5000mah 20c packs. A little bit on the heavy side but perform OK on their 2nd season. IR is in the range of 2-4 millOhms.
As a comparison, that of the f3aunlimited 20C packs is around 1-2 millOhms, and that of the Blue from hobbypartz.com is approaching 5-7 millOhms (2nd season).