get a 9.6v 1400 mah intellect.
top of the line battery
I tested out my 8.4v battery on the JG g36c, and 700 RPM sounds very very slow. U'd be surprised on this forum what ppl report for RPM. Average for most aeg's is 800-1000 w/8.4v . u get 1000 RPM on a lot of longer CA rifles and with just 8.4v.
9.6v battery should boost the RPM of JG to like 1000-1100RPM, and u should use a 9.6v for a 380 fps spring anyways