I don't know for sure what the protocal is about charging li-pos occasionally but during the off season I plan on getting mine out and doing just that.
Interestingly,when I took them home for a charge the bats only took a 17 minute charge. I didn't check to see how many amps they took on but it couldn't have been many.
I'm going to take the plane out again today.
Incidentally, I burned out my charge gard. I think because I disconnected the battery but probably should have gotten the clips off the car battery first.