“Your iPhone Battery May Need to be Serviced”
This notice might appear on any iPhone running iOS 10.2.1 or later in Settings > Battery. As Apple Support wrote, “this isn’t a safety issue, it’s just to let you know that your battery may need to be replaced. You can continue to use your iPhone until you have your battery checked.”
If this notice has appeared on your phone, it simply means that iOS diagnostics have detected that the battery in your phone may need to be replaced as it is starting to lose capacity. When a battery gets closer to the end of its lifespan, the amount of charge and the ability to provide power reduces. As a result, a battery may need to be charged more and more frequently, and your iPhone might experience unexpected shutdowns. There are various factors that can affect the performance and lifespan of your device’s battery, including number of charge cycles, age of your battery, and exposure to extreme heat or cold.
When the battery in your device is degraded, the nominal voltage is also lessened. 3.8 is typically the voltage needed. When the cells are compromised the voltage it can sustain is all affected and will slow the phone or even shut it down during high strain situations.
For more optimal battery life, one might want to replace their battery yearly, especially people living in colder climates. It's one of the cheaper services that are offered and can help to maintain proper phone function as well as prevent some of the damage that can be caused by a battery going bad (i.e. bloating up and cracking your LCD).
Technicians at Wires Computing replace batteries (and charging ports) daily, and would be more than happy to assist you in servicing your phone. No appointment needed— feel free to just drop in during our regular business hours.