Mate, you don't need to stand 5 meters away from your test stand! If you are behind the running power unit you are safe if it blew up!
With better quality, higher C rate packs you'll notice dramatic difference in performance figures.
With few of mine 127mm fans on 12S I'm getting 9.5 to 10.5 kilo static pull at some 200 to 240 Amps, subject to capacity and Crate of batteries I use.
This is not on the stand, but fitted inside model. There are lot of idiots on other forums who never believed my figures and laugh at me calling me all the crap, but it's always me who is laughing while flying my models.