RE: ECO 8 and lipos
well the thunder power 3s2p from hobby lobby might work because its advertised up to 40 amps, but its $130. what i will do soon and i suggest you do it too is go to cheapbatterypacks.com and go to custom packs and order a GP 3300 nimh pack. any cell size you want with any wire and connector. a 10 cell is $60.