A few days ago I took my MBP to class at university, and when it booted up I noticed it had only ~45min of battery life. I checked the health in iStat and saw that it had a very low health: The thing is though halfway through the battery, the health shot up to 88% or so, and my battery life returned to sane amounts. So I thought it was just a calibrating issue, took the computer home, drained the battery, and recharged it after a couple of hours. next boot, everything was fine and dandy (though still at 88% health which bothered me a bit). The problem is that halfway through that, the battery health suddenly fell again to the same amount as attached above, and my battery life took a dive. So yet again I took it home and calibrated it. However now whenever I run it on battery, no matter how many times I calibrate it, the health stays at 25%. Sometimes it goes up to 27%, but overall it's really low. Right now with my battery, no matter how often it is used, calibrated or recharged, I get a steady 25% health and ~50min battery life. What's wrong with it? and given the low amount of cycles relative to the health, is there grounds for a replacement battery on this 1.5 year old out of warranty and non-applecared computer?