Should I trust my battery vendor?
UPD. It turned out to be quite a lengthy question, so I highlighted the key points in bold.
The cycles of my original battery began to exceed 1.3k, the capacity dropped to 67.8%, and the operating system began to report that "Service Recommended."
I decided to replace the battery and searched for a local battery dealer (iFixit won't ship batteries in my area) and tried to find a brand-name battery of some sort. I found something that the seller claimed was a product from BayEagleEyes Technology Co. for about $97, which I bought.
Immediately after replacing it, I charged the battery to 100% and left it plugged in for a couple more hours. After that, I looked at what capacity the battery was showing. Unfortunately, it displayed 5846 mAh instead of the claimed 8775 (just 68%).
I decided to calibrate it. To do that, I discharged it before turning off the laptop and left it turned off overnight. In the morning, I plugged it in and fully charged it again. Now the battery was showing even less, 5590 (65%).
So, I reset the SMC. Then, I repeated the charge-discharge-recharge cycle. Again it showed even less, now 46 mAh (62%).
With each charge-discharge cycle, the displayed battery capacity was dropping.
However, I noticed one oddity - the indicated charge percentage mostly dropped evenly, and then at about 6-7% it froze for about an hour.
I wrote to the seller. The seller answered that the only sign of a bad battery could be the battery life. A non-genuine battery in an Apple device will never show the actual charge and percentage, they said.
I set up an experiment. Fully charged this new battery, turned on the computer, and loaded the CPU to 100%. The battery lasted almost two hours.
Then I put the old, original battery back in. Charged it fully, loaded the processor to 100%. And indeed, the original battery ran out much faster - in about an hour.
What to do, who to believe? Should I insist on replacing the battery? Perhaps there is some magic calibration that will make the new battery show the correct numbers?
Esta é uma boa pergunta?