Sure enough! I just got my EagleTree data and every time it hits 60 amps or greater, the voltage drops to 12V or below. To be a little fair though, they weren't freshly charged this time. They started at 3.9V/cell.
The peak current was 130A and that dropped the voltage to 9.1V. Yikes.
I have 4 total 2s 6K MaxAmps packs, so I'll have to test a few more combinations of them to see if I can narrow down one of them that might be causing the problem.
For this graph, I just averaged the voltages for everything under 110A.
