Not enough for 2 packs and still get the canopy on. Main reason I didn't convert it to glow, not enough room for a tank, even with cutting the floor out, there is about half a centimeter between the floor bottom and the top of the wing, and the packs I have now just fits height wise with some wiggle room under the canopy, so I can put a somewhat larger pack in ti, I just have to measure and find one that fits. Weight shouldn't be a problem as long as I can keep it forward, this plane tends to be tail heavy if the pack is not all the way forward.
Now, Gen Ace, or Sky Lipo?
Preferences on brands? The Gen Aces seem to be pretty good for what I have, but tend to bleed off quickly when they get warm. This has been my major headache with eth T-34, it draws some juice when full throttle, so when I play it tends to be short flights, the alarm goes off after just a few minutes, but after I land and let it cool down the voltage jumps right back up to at least 3.8, but in my Apprentice I can fly 15 minutes on the same pack.