I have bought a used MacBook Pro from 2011 with a Core i5 (2.3 GHz) and 8 GB RAM. According to the previous owner the battery has been replaced late 2017 and according to macOS it only has as much as 16 cycles and something around 6000 mAh (Is that sound? I haven't got the MBP around.). The previous owner sent me the invoice from an official Apple partner (Gravis) that replaced the battery with an original one. The system has been installed from scratch and updated to High Sierra.
Anyway, the reported charge drops quite fast. I did nor run the MBP until it shut down due to a low battery, but extrapolating from the charge, the battery life should be around 2 h or so. I have been running AppCode, occasionally building and running a simple app. Xcode is also running to edit storyboards once in a while. WiFi has been disabled.
Given I can trust all of the statements made above (new battery, original parts, roundabout 6000 mAh, 16 cycles) this battery life seems quite low-ish to me. Are there any further sources of battery drain (or some leakage) I could possibly examine in order to investigate what causes this low battery life? Or is this quite normal for a device that is nearly 8 years old? Is some kind of current leakage possible if the MBP runs on battery?