Air Hogs boat/plane thingy LiPo question.

[JOHNNYMAXXIMA]

I had a spare LiPo battery laying around from a little helicopter that I have. It is a 2s 600mah. I decided to use this batt on my Air Hog Storm Launcher as a spare. Now if you havn't seen the 2s that comes with the Air Hogs here is a pic bellow. You must insert the pack onto the pos. & neg. poles. So with the spare LiPo that I have, I installed a pair of 4.5mm female gold connectors on to it to slide over the pos. & neg. poles. See pic below. (sory for the blury-ness)


Once connected and powered up, everything is working fine (elevator and motors) until after I release the throttle after the first time. When I try to accelerate again, it goes into a cutoff mode or something, all power is gone until I unplug and plug in again then the same cycle happens again. I don't think it has anything to do with connection because I have to use just a little bit of force to get the gold plugs slide on.

Could it be because the mah is not the same? The Air Hog is 740mah and my spare is 600mah.
Thanks.