If you paid to replace the battery in your iPhone 6 (or a later model) out-of-warranty between January 1 and December 28, 2017, you might be eligible for a $50 credit from Apple. The Cupertino-based technology company announced the decision on their website, which informs users that eligible battery replacements are those that were performed at authorized Apple service centers.
Last year, Apple was accused of throttling older iPhones, resulting in slower performance in some cases. What Apple did confirm is that they were limiting spikes in power consumption using an algorithm to avoid overloading batteries (due to declining capacity), so that iPhones don’t unexpectedly shut off.
Heavy CPU usage can cause such spikes, so the power consumption of the CPUs had to be limited. This problem can occur in phones that have older batteries, or if they are exposed to extremely cold weather. Cold weather limits the discharge current capabilities of lithium-ion batteries.
I have experienced this issue with older phones of other brands shutting off suddenly, and would have appreciated it if they had an algorithm to prevent that. Many thought that their motive was to drive people to upgrade their phones by making them slow.
Whether or not that influenced Apple’s decision to throttle them, the unexpected shutdowns justify it. An ideal solution would be to enable users to turn that feature on or off.