battery full but no power?

How old is your battery and if you have had it awhile, how have you been maintaining it?  As offgrid wisely stated above you need a multimeter.  Then you can check the voltage of your battery.  Firstly make certain that your electrolyte levels are full or nearly full, if one of those six cells is empty, your battery is likely toast.  Fill any low cells to full using distilled water.  Next check battery voltage using your multimeter - should read at least 12.2volts at the low end.  If it reads that low you need to put it on a trickle charger (2 amp is great) for at least 24 hours.  Read it again at that point, let it set for a few hours and then read again.   Those two readings should be nearly identical if the battery is good.  Also make sure the connections at the battery are tight using a wrench, getting it finger tight doesn't cut it here.

I just re-read your original post and am thinking out loud, how long did the battery sit being connected to the pod?  There are numerous phantom draws that will deplete the battery down below acceptable levels after 10-14 days.  If you don't plan on using it within a week either disconnect the ground (-) cable or hook up a disconnect switch so you can more easily turn off battery power when not using your r-pod.