iPhone models have a Battery Health feature that gives you a fair idea of depleting battery capacity over time, as well as tools to optimise battery health and slow down the ageing process. While this is a fair indicator of your battery age, you can can also assess the health of your iPhone's battery by checking its charge cycle count - taking a peep into the logs. A battery cycle count is essentially the number of times your battery has fully drained out battery and then been fully recharged again.
One cycle count is completed only when the iPhone completely depletes 100 percent of the battery. So, even if you charge the iPhone mid-way through the battery drain, a cycle will only be completed when the iPhone depletes its charge completely.
Just like all batteries, [iPhone](https://gadgets.ndtv.com/tags/iphone) batteries are also consumable components that deplete in capacity over time. If the battery becomes too weak, users may notice reduced battery life and slow performance of the iPhone. According to [Apple](https://gadgets.ndtv.com/apple), a normal battery is designed to retain up to 80 percent of its original capacity at 500 complete charge cycles when operating under normal conditions. To check whether you've reached this milestone or not, users can follow the below mentioned steps. The battery log can only be accessed if the user has enabled sharing of analytics. For checking whether the analytics sharing is enabled, one can check from here - Privacy > Analytics & Information.