RE: Slow Stick Battery ... Lipo
Most Slow Sticks I have seen come with the GWS EPS 300C motor which is a 370. You seem to be saying yours came with the EPS 100C which is a 280. Are you sure on this?
Anyway, the EPS 300C(370) will fly on an ETec 1200 2S1P pack. However, the GWS EPS 400C (380 motor) really needs 3S (11 volts) LiPos to run strong. I'm not sure that ETec 3S 1200s will like the current of the 380 motor though. The 1200 is a 5-6C cell and that is only 7 amps. You would probably need a 3S2P Etec 1200 pack or a 3S1P TP 2100 pack. I currently fly the EPS 400 on a SS with the TP2100 3S1P and it's a nice combo. The TP2100 is a 6C pack and can safely provide 12 amps.
Sierra Gold