I recently just bought a replacement battery for my S7. I have a USB mAh tracker and according to it the amount of mAhs going into the battery has really decreased after calibration, not to mention that it never hit 3000 mAh the manufacturing capacity. I followed the direction on the package for calibration, after charging to 100% for more than 2 hours I used it up till it was empty. Then I charged it to 100% but that totaled 2400mAhs. Now it’s totaling 2000 mAh, I don’t know what’s going on.