Ursprünglicher Beitrag von: Minho ,
Don’t trust what the battery data says. It’s easy to program the battery to say whatever you want, like 0 cycles/100%. A cheap supplier will take crap cells, with a used battery gauge board and program it to look brand new. However, even a good/great supplier will have duds. And it’s generally not true that suppliers test every part. With batteries, it’s unfeasible because it takes 5-8 hours to properly test one battery. A select few vendors are investing in a big way to test their batteries but it requires a substantial financial investment. So if you bought the battery with iFixit, give Support a call. If you bought it elsewhere, see what they are willing to do.