Low battery indication for callers to mobile device

A mobile device, comprising:

• a network interface to communicate with one or more remote systems;
• a battery;
• one or more memories to store instructions;
• and
• one or more processors configured to execute instructions in the one or more memories to:
• determine that a low-battery condition exists;
• send, to a second mobile device, a battery status signal indicating the low-battery condition;
• receive a notification of an incoming call from a calling device to the mobile device;
• provide, to the calling device, a challenge to solicit a categorization of the incoming call as important or not important;
• receive, from the calling device, a response to the challenge, wherein the response includes the categorization of the incoming call;
• and
• accept the incoming call from the calling device to the mobile device when the categorization of the incoming call is important.

A calling device, comprising:

• a network interface to communicate with one or more remote systems;
• a battery;
• one or more memories to store instructions;
• and
• one or more processors configured to execute instructions in the one or more memories to:
• store, in the memory, a battery-saver agent application;
• receive, from a mobile device of a contact that is associated with the battery-saver agent application, battery status information of the mobile device;
• store the battery status information from the mobile device;
• receive, from a user, an input to select the contact corresponding to the mobile device;
• determine a low-battery indication for the mobile device based on the battery status information when the contact corresponding to the mobile device is selected;
• and
• notify the user, based on the battery status information and in response to the input, of the low-battery indication for the mobile device.