Hi there,
my battery capacity is about 5600mAh not 6580mAh as you declared on site. I charged the phone about 25 times and app AccuBattery show Estimated capacity 5544mAh and battery health 84%.

Can you check it somebody for your measurement? I think my battery is bad from the factory or it is normally?

Thank you

Don't worry, the battery is as declared on our site. Monitoring apps like the one used by you always have misreadings