I clipped my battery tray long ago (on both of my CX2's) and now use velcro on the bottom of the tray, on my LiPo packs and then use a velcro strap to secure whatever pack I am using. This allows me to use "non-standard" packs for my CX2. Case in point being the Xtreme 18C packs from USHOBBYSUPPLY.com and the FlightPower 20C 3S 11.1V 1385 mAH pack! You should see the FP pack on my CX2. It looks pregnant! However, the extra power you get from a higher C pack, plus the extra voltage from a 3S pack MORE than makes up for the added weight!! It so powerful that I won't fly the FP pack inside anymore!