ORIGINAL: BryFlyGuy67
I've altered my battery tray as well. I've clipped out the battery supports that hang down from the cross members and then, like soloboss, I use a velcro strap to secure the battery in it's place.
Advantages: accommodates all kinds of battery packs. Is easier to position the battery fore and aft for COG balancing.
Disadtantage: Battery is prone to slipping, especially when your velcro strap isn't tight enough or you get into a crash. I always re-check COG after a crash or hard landing now.
Speaking of other LiPo packs, if you have done the mods to your battery tray as described in this thread, you can run the Xtreme 7.4V, 850 MAH, 18C packs! I got two of them from Michael over the weekend. I few one of these packs in my non-Xtreme CX2 last night and it was amazing! I was flying fairly aggressively outside - non-stop for a full 10 minutes - and not once did I feel a loss of power! The packs won't fit into the stock CX2 battery holder, though. That's why you have to be running the modified tray to use them.
I addressed the slipping battery by sticking a velcro patch to the battery. I place the battery under the velcro, then slip the battery fore / aft to set the COG. Then I mark the location where the velcro strap crosses the battery and I epoxy a velcro patch there. With that arrangement, the battery is always located at COG and it doesn't move during a crash or bad landing.
Did I cover that the first time or am I being redundant . . . again?