BatteryBot Battery Indicator is the original battery indicator app for Android™, released in 2009 as simply "Battery Indicator." Both the free and the Pro versions have maintained a 4.5+ star rating in Google Play from the beginning. It offers two modes: the original status bar indicator and now also a desktop widget. You can use either or both, as you please.

BatteryBot monitors and shows your battery charge level (percent) as an icon in your status bar, with how much time you have left, temperature, health, voltage, and time since plugged / unplugged in the notification area. It now also has a 1x1 app widget. The Pro version also has user-configurable alarms, logs, mA current information, and a large (4x1) widget.

Give it a try -- it's an excellent and complete solution to your battery needs.

Features:

• No ads (why would you want a battery app with ads?)
• Exact battery level in the task bar
• Or hide the task bar icon, keeping notification in tray — or turn notification off completely and just use widgets
• Multiple icon set options
• Automatic time-remaining estimates based on recent usage
• Small (1x1) circle desktop widget
• Very lightweight (please email me if you think otherwise, and I'll help you figure out what's wrong — I promise this app will not drain your battery!)
• Well-tested and supported on all major versions of Android (4.1 through 8.0; Jelly Bean through Oreo) and form factors (small phones, medium phones, large phones, 7-inch tablets, 10-inch tablets).
• Open source

For those who want more than is offered in the free version, or for those who just like to support small, independent developers like me, the Pro version remains lightweight while packing in many useful features:

Pro-only Features:

• Alarms (fully charged, charge above X, charge below X, temperature above X, or health failure)
• (On devices that allow it — Note that most devices on Lollipop and up, 5.0+, do not, so this is mostly only for old devices) Icon colors (including fully configurable green, amber, red, and black icons)
• (On most devices) Electric current (mA / milliamp /milliampere) reading to/from battery on supported devices
• Large (4x1) desktop widget
• Battery logging. You can log the battery state (charge, status, voltage, temperature) and browse the logs on the phone or export to CSV.
• Control the notification priority on Android 4.1+ (For example, you can set to "minimum" to hide the icon but keep the notification in the tray.)
• Lots of configurability of behavior and appearance.
• The charging indicator (the bolt under the number that indicates when the device is being charged) for the sets that have it is optional in the Pro version.

~~~~

Follow the Google Plus group for announcements and occasional polls about the app:

https://www.google.com/+BatterybotInfoAndroid

~~~~

A one-time purchase now gets you free updates for life on all your Android devices.

~~~~

All requested app permissions are explained on the project website. On devices running Android 6.0 or newer, permissions are requested as needed and not used otherwise.

~~~~

Please email me if you have any questions or comments.

~~~~

Here's the BatteryBot business model / philosophy:

1) Ads are annoying. For some apps, ads might make sense, but a system utility should not have ads.

2) The free version should be simple but useful; it shouldn't feel crippled.

3) Some people choose to purchase the Pro version because they want extra features, some because they want more customization, and many because they just want to say "thanks" for the free version and support small, independent developers like myself.