Answer to: Battery Hardware Error CodeI have several of the MacBook Pro (15-inch Early 2011) Intel Core i7-2635QM 2000 MHz (4 cores). I have replaced with a no brand battery and had about the same AHT error. Loading was ok, but I noticed that the machine was a bit slow. EtreCheck show "good" performance. But I ran Geekbench to check CPU in more detail. I had 897 single / 2803 multi. Very unsatisfactory. Because when using the orginal A1382 from Apple the CPU goes with 2460 single / 7971 multi. With this no brand I lost about 66% of the performance. If you look into Geekbench with "MacBook Pro 15 2011" you find plenty of such performance differences. I believe that the low findings correspond with no name batteries.