I'm pretty sure iFixit checks these batteries extensively before selling them. Besides, 2 batteries with the same exact issue is a little puzzling. I would start to look at the connections to the logic board and the Logic Board itself. Why were you replacing the battery to begin with? was it liquid damage? If so, I would look under the search tab for "liquid spills" / "water damage" for more suggestions if that was the reason the battery needed to be replaced to begin with.