Apple includes a power management algorithm that allows owners to keep using their old iPhones by preventing unexpected shutdowns even when the battery is degraded and the trollosphere goes ballistic. Dozens of threads are created featuring befuddled arguments, while only a few rare threads such as
A Battery Scientist's View attempting to actually understand the complexities of lithium-ion batteries and power management algorithms.
I usually keep my iPhones for a full 5 years and appreciate the fact that Apple provides me with system and security updates throughout the product's entire life. I am happy to pay the relatively high upfront cost to have a device that I can count on to work for me for half a decade without having to micromanage every little system decision along the way. Despite the limits imposed by physics, I truly appreciate the current state of battery technology - it has always been a rather black art to manage miniaturized mobile power, and have not forgotten what a luxury it is to have a pocket size computer always at the ready. This is also the reason that iPhone's have such a high resale value. I fully support Apple's power management decision with overloaded degraded batteries to slowdown my iPhone rather than to let it shutdown.