Chosen Solution
I’ve got a problem with the speed of the iPhone 6S after replacing the original battery with the battery from iFixit. The Geekbench score is just half as fast as normal, 1000 Points in Single-Core and 2000 in Multi-Core. Has someone already seen this problem? Tanks!
This was likely done to mitigate sudden shutoff issue. Newer iOS versions identify potentially defective battery by model and serial number of the battery, if it is in defective range, the system limits max burst output. It’s not that the battery is actually defective, it’s just your replacement one has that serial number.
