I've read the many threads on this, but I'm still not too sure if this behavior is normal. First of all, I've never accurately calibrated my battery (I know, I should have) and have had my MBP C2D 15'' for about 5 months. I finally calibrated it yesterday. However, before this something odd happened. I almost always have my laptop plugged in and on full charge and occasionally take take it off for about an hour, but the use is mostly plugged in and fully charged. So the other night I was packing things up to move, I unplugged my laptop and had it off for about 24 hours. When I turned it back on the next day the battery was about 75%. When I'm using it off the battery it doesn't seem like it drains especially fast, but when off and unplugged it seems to drain quickly. IS that quickly, or are these batteries designed to drain quickly to about 50% if they're off (since that is about the safest place for them to be). Another odd thing, coconut battery lists my battery age as 8 months and I bought it in late December brand new. My battery health right now is at 92% with 15 charges. I've heard that if you keep it on A/C power most of the time you should just leave the battery out, but I hate the thought of my laptop being open underneath. Does leaving it in really hurt it that much? Thanks for any information!