If you are looking to save battery life, modern Android versions (Android 10 and newer) have built-in tools that are safer and more effective than third-party apps:
Flagged. The "DU" suite of apps (owned by Baidu) was removed from the Google Play Store in 2019 due to large-scale ad fraud and malicious behavior, such as clicking ads in the background without user consent. free-download-du-battery-saver-pro-3-9-9-9-8-2-apk-2021
Manually or automatically restricts background activity and visual effects. If you are looking to save battery life,
The app has been known to collect excessive user data and transmit it to external servers without clear disclosure. Better (Safe) Alternatives free-download-du-battery-saver-pro-3-9-9-9-8-2-apk-2021