That generally won’t happen until the maximum capacity is lower than 80 percent after 500 complete charge cycles (read more about that in our story about battery myths).
At what percentage should iPhone battery be replaced?
At what battery health should I replace?
You should replace the battery when the battery life bothers you enough you are willing to spend the money to have the battery replaced. It really is as simple as that. For some people, that might be at 80% of its original capacity. For others it might be as low as 20% of its original capacity.
Is 91 a good battery health?
As the lithium-ion battery chemically ages, it will have a lower capacity when compared to new batteries. So, if your battery is reading 91%, you will probably have to charge your iPhone more frequently than you did when your battery was reading 100 percent. This iPhone is unable to determine battery health.
How long should iPhone battery last?
Average battery life: Around 5 to 11 hours for both phones. Released in 2012, the iPhone 5 featured a 1440 mAh battery, and Apple claimed a single charge on this device could last up to 225 hours if the phone wasn’t in heavy use.