Droid X extended battery issue

I've been using a droid x with an extended battery for the past couple of weeks. Loved it, gave my droid probably an extra 20-30% more battery life.
After recently going on a snowboarding trip my droid's battery has not been lasting as long as it used to, usually dying within about 12 hours when it used to last 16-20 easily.
Nothing has changed since I took it snowboarding (it was left with someone in the cabin and brought out for only a few mins at at a time, temp on the mtn was about 30F)
Ive charged and uncharged it fully at least 3 times with the battery still only lasting about as long as my brother's droid x's standard battery (again, we're both running the same setup, rooted with custom rom)

Anyone have any ideas?

 

Yep, tried that yesterday. Phone made it about 12 hours. Might take it into a verizon store to see if they know what's up with it