hi, my current battery thats been the original since first purchase is dying on me. says that the battery needs service and health is fluctuating b/w 73% and 88% according to istat pro. I'm looking through amazon and ebay for cheap replacements but I'm not totally confident in purchasing. i want to know if any of you purchased batteries from them or if it is a safe buy. thanks ps. they state higher capacity mAh than oem. is that true??