An electronic timepiece includes a secondary battery, a first power feeder, a second power feeder, and a processor. The first power feeder feeds power to the secondary battery. The second power feeder feeds power to the secondary battery at a current larger than a current fed by the first power feeder. The processor determines remaining power of the secondary battery based on different references that are a reference of when the first power feeder is feeding the power to the secondary battery and a reference of when the second power feeder is feeding the power to the secondary battery.

An electronic timepiece includes a secondary battery, a first power feeder, a second power feeder, and a processor. The first power feeder feeds power to the secondary battery. The second power feeder feeds power to the secondary battery at a current larger than a current fed by the first power feeder. The processor determines remaining power of the secondary battery based on different references that are a reference of when the first power feeder is feeding the power to the secondary battery and a reference of when the second power feeder is feeding the power to the secondary battery.

A thermoelectric watch including a thermoelectric generator; a voltage booster connected to the thermoelectric generator; an energy management circuit connected to the voltage booster and configured to control the charging of at least one energy storage element, the energy management circuit including an output configured to change from a first logic state to a second logic state when the thermoelectric generator starts generating electrical energy, and to change from the second logic state to the first logic state when the thermoelectric generator finishes generating electrical energy.

A thermoelectric watch including a thermoelectric generator; a voltage booster connected to the thermoelectric generator; an energy management circuit connected to the voltage booster and configured to control the charging of at least one energy storage element, the energy management circuit including an output configured to change from a first logic state to a second logic state when the thermoelectric generator starts generating electrical energy, and to change from the second logic state to the first logic state when the thermoelectric generator finishes generating electrical energy.

A watch is provided that includes a constant current circuit including: a plurality of transistors coupled in series between a first power supply and a second power supply, the first power supply being a power supply of a high potential side power supply, the second power supply being a power supply of a low potential side power supply; a plurality of connection wiring lines each provided for each of the plurality of transistors, and configured to couple the first power supply and a terminal on the first power supply side of each of the plurality of transistors; a non-disconnected fuse provided in a non-disconnected state to one connection wiring line of the plurality of connection wiring lines, and a disconnected fuse provided in a disconnected state to a connection wiring line other than the one connection wiring line of the plurality of connection wiring lines.

Provided is an electronic clock including: a power generator; a secondary battery, which is to be charged with electric power generated by the power generator; a balance information transmitter configured to transmit, to a computer, balance information relating to a transition of a power generation amount or a charging balance of the secondary battery; a connection time period setting module configured to set a connection time period of a connection with the computer based on the balance information; and a communication controller configured to control a start and an end of communication to/from the computer based on the connection time period.

Provided is an electronic clock including: a power generator; a secondary battery, which is to be charged with electric power generated by the power generator; a balance information transmitter configured to transmit, to a computer, balance information relating to a transition of a power generation amount or a charging balance of the secondary battery; a connection time period setting module configured to set a connection time period of a connection with the computer based on the balance information; and a communication controller configured to control a start and an end of communication to/from the computer based on the connection time period.

A watch is provided that includes a constant current circuit including: a plurality of transistors coupled in series between a first power supply and a second power supply, the first power supply being a power supply of a high potential side power supply, the second power supply being a power supply of a low potential side power supply; a plurality of connection wiring lines each provided for each of the plurality of transistors, and configured to couple the first power supply and a terminal on the first power supply side of each of the plurality of transistors; a non-disconnected fuse provided in a non-disconnected state to one connection wiring line of the plurality of connection wiring lines, and a disconnected fuse provided in a disconnected state to a connection wiring line other than the one connection wiring line of the plurality of connection wiring lines.

A caseback has multiple, arc-shaped, ferrous, metal contacts that serve a dual purpose. The metal contacts i) establish an input connection between a battery for the wearable electronic device and charging prongs of a charger and ii) establish a magnetic coupling between the wearable electronic device and multiple magnets in the charger to hold the metal contacts of the wearable electronic device and the charging prongs of the charger in place during a charging of the battery. A male extension extends from a surface of the caseback to couple into a female receptor of the charger. i) The ferrous metal contacts' relationship with a positioning of the magnetics in the charger in combination with ii) the male extension coupling into the female receptor use magnetic and mechanical coupling to establish and control an alignment of the metal contacts with the charging prongs in three dimensions, a Z-axis, an X-axis, and a Y-axis.

A caseback has multiple, arc-shaped, ferrous, metal contacts that serve a dual purpose. The metal contacts i) establish an input connection between a battery for the wearable electronic device and charging prongs of a charger and ii) establish a magnetic coupling between the wearable electronic device and multiple magnets in the charger to hold the metal contacts of the wearable electronic device and the charging prongs of the charger in place during a charging of the battery. A male extension extends from a surface of the caseback to couple into a female receptor of the charger. i) The ferrous metal contacts' relationship with a positioning of the magnetics in the charger in combination with ii) the male extension coupling into the female receptor use magnetic and mechanical coupling to establish and control an alignment of the metal contacts with the charging prongs in three dimensions, a Z-axis, an X-axis, and a Y-axis.