Hello Sir, I buy the Blackview 9100pro on presale. I am using the phone since 20 days. My uses is same as with my previous Blackview BV8000 pro and they last 1.5 days after full charge. 
But Blackview 9100 pro gives 3 days after full charge. Also I check with Accubattery App it shows 12000 mah capacity of the phone.