Apple confirmed in December that it applies certain "optimizations" to iPhone phones equipped with battery packs that have reached near end of life, but that significantly reduces device performance
The official explanation is that an "aging" battery might not keep up with the device's power needs, causing spontaneous shutdown of iPhone phones when they are more intense. The solution found is the artificial limitation of energy consumption and, implicitly, performance. Not surprisingly, the news that Apple deliberately reduces the performance of older generation devices has sparked controversy, casting doubt on the company's good intentions
Apple's solution was a lower cost for replacing on-demand batteries, and the promise of adding a set-up to disable mock optimizations in a future iOS version.
It is certain that the decrease in performance in the affected devices is noticeable in everyday use, which is also confirmed by repeating the performance tests after replacing the battery. Practically, from a score of 2485 points in the Geekbench multi-core test, it reaches 4412 points, reflecting almost double the level of performance