how many MAH does a lipo lose in 2 weeks

I was told I would be out of teh country for work 3 weeks - before I went, I ran as many of my lipos as possible and charged them to 50%. The ones I didn't run I discharged and then charged to 50%.

I was gone almost 3months and when I got back all of them had puffed a cell.
I hear storing them at 100% is bad for longevity, but I don't think much of the 50% business either. I'm using 80% and checking them at 1month if I don't think they'll get used. Haven't seen any probs. TCS function on my 0610i charger makes this real easy - just tell it what percent you want and it does the rest.

Def do some kind of maintenance on them - a year and they will be overdischarged.