battery problem

Hi, i've read prior posts about battery problems, and i was wondering if someone could help me out. i've got a 2 1/2 year old mbp, with a battery that i received in 11/07. right now, it has 220 cycles, however the life of it keep fluctuating (i use istat and coconut battery). i've tried calibrating it 3-4 times within the past two months, but it does not seem to help. After charging, it might state that i have 86% health, but cuts off when power is at 30%. After calibrating, it will actually tell me that i have a battery health of 74%. But after I charge it one time, it shoots back up to the 80's percentile, which is incorrect. does anyone have any advice on how to fix this since my warranty on the battery is over? thanks