--- title: "If my cellphone's battery drains slowly from 100% to about 40% then drains very quickly, does that mean the battery is bad?" description: "If my cellphone's battery drains slowly from 100% to about 40% then drains very quickly, does that mean the battery is bad?" author: "Lily Chitlangiya" published: 2021-12-21 canonical: https://answers.mindstick.com/qa/94757/if-my-cellphone-s-battery-drains-slowly-from-100-to-about-40-then-drains-very-quickly-does-that-mean-the-battery-is-bad category: "troubleshooting" tags: ["android", "battery", "troubleshooting"] reading_time: 2 minutes --- # If my cellphone's battery drains slowly from 100% to about 40% then drains very quickly, does that mean the battery is bad? [If my cellphone](https://answers.mindstick.com/qa/109367/what-to-do-if-my-cellphone-s-display-screen-freezes-and-will-become-unresponsive)'s [battery drains](https://answers.mindstick.com/qa/108756/what-if-the-tablet-battery-drains-fast) slowly from 100% to about 40% then drains very quickly, does that [mean](https://yourviews.mindstick.com/view/80630/what-does-it-mean-to-be-paperclipped) the battery is bad? \ ## Answers ### Answer by Hitesh Vohra - If you've ever noticed that your **phone's [battery](https://answers.mindstick.com/qa/50950/how-to-configure-battery-saving-mode-settings-on-your-iphone-6s-plus)** drops from 60% to 50% in a matter of minutes, only to stay at 50% for what seems like an eternity, it's likely time to calibrate the battery. - Batteries degrade naturally over time, and their capacity gradually diminishes. However, your phone isn't always accurate in this regard—if your battery has declined to 95% of its original capacity, your phone may still show it as 95% full rather than 100% full (the 'new normal'). - Allowing the battery to go from entirely full to completely empty on a regular basis might harm it and reduce its capacity over time. On the other hand, leaving your phone plugged in when it's totally charged can cause the battery to degrade. - Select **Settings > Device > Battery or Settings > Power > Battery** in most Android versions. To get a list of all apps and how much battery power they're using, go to Settings > Battery. Consider deleting an app you don't use very often if it appears to be using a lot of power. - By tapping it on Android 9, you can observe how power-hungry apps are wasting battery. You'll be able to enable 'Background limitation' for some apps. Keep 'Battery optimization' turned on for all apps. \ \ **Read More: [Is it normal for a 7% battery to drain in 30 mins?](https://answers.mindstick.com/qa/94758/is-it-normal-for-a-7-battery-to-drain-in-30-mins)** --- Original Source: https://answers.mindstick.com/qa/94757/if-my-cellphone-s-battery-drains-slowly-from-100-to-about-40-then-drains-very-quickly-does-that-mean-the-battery-is-bad Copyright © MindStick Software Pvt. Ltd. This Markdown version is provided for developers, AI systems, and offline reading.