Battery Level Rainbow can display battery status and available charge in three ways: as an icon with colors representing the level of charge and charging status, as an app widget with a larger version of the icon and the percentage of charge available, and as a graphic with the same information as the widget as well as the percentages where the level color changes.
The icon has three parts: a battery-shaped border, a stack of colors (in rainbow order: red, orange, yellow, green, blue, and violet) at the bottom, and a color at the top indicating the charging status. The number of colors at the bottom indicates the charge level. The color of the border is usually the top color of the stack.
The upper part of the icon is white for charging, black for discharging, and brown for not charging. If the status reported by the device's Battery Manager is not recognized, the entire icon is a solid gray. if the battery is reported as fully charged, the upper part of the icon is a checkered pattern; if the charge is at the highest level, the upper part and border of the icon is a black-and-white checkered pattern, similar to that of the finish flag at an automobile race; otherwise the upper part is a light-gray-and-dark-gray checkered pattern, and the border is the top color of the stack.
The status updates can be stopped by the Android system to provide storage for a higher-priority process (this should not happen often); if this is the case, the icon will be a solid gray with a red "not permitted" symbol (a circle with a diagonal line) inside.
The large version of the icon uses the same colors, except that the border is always the top color of the stack.
When the notification list is pulled down from the status area, the battery icon is accompanied by a message indicating the battery's status. If the battery status is discharging or not charging and the charge is lower than a percentage that can be set by the user, a "battery low" message is shown. If the battery is not charging or the charging status is unrecognized, a "not charging" or "status unknown" message is shown. If the battery is reported as fully charged but the available charge is not at the highest level, a "not full" message is shown. If Android stopped status reporting, an "updates stopped" message is shown. Otherwise, a "battery normal" is shown.
Touching the notification list item for the application will display the graphic with full information. Pressing the Menu button will bring up the application's menu.
The preferences menu allows the user to set the percentages at which the level of charge changes and the percentage at which the battery low message occurs.
