Power storage system and power storage device

Abstract

The versatility of a power feeding device is improved. A power storage system includes a power storage device and a power feeding device. The power storage device includes data for identifying the power storage device. The power storage device includes a power storage unit, a switch that controls whether power from the power feeding device is supplied to the power storage unit, and a control circuit having a function of controlling a conduction state of the switch in accordance with a control signal input from the power feeding device. The power feeding device includes a signal generation circuit having a function of identifying the power storage device by the data input from the power storage device, generating the control signal corresponding to the identified power storage device, and outputting the generated control signal to the power storage device.

What is claimed is: 
     
         1 . (canceled) 
     
     
         2 . A power storage device comprising:
 a power receiving circuit;   a power storage unit;   a first transistor between the power receiving circuit and the power storage unit;   a second transistor between the first transistor and the power storage unit;   a third transistor between the second transistor and the power storage unit; and   a control circuit electrically connected to a gate of the first transistor, a gate of the second transistor, a gate of the third transistor, and the power storage unit,   wherein the power receiving circuit is electrically connected to one of a source and a drain of the first transistor,   wherein the other one of the source and the drain of the first transistor is electrically connected to one of a source and a drain of the second transistor,   wherein the other one of the source and the drain of the second transistor is electrically connected to one of a source and a drain of the third transistor,   wherein the other one of the source and the drain of the third transistor is electrically connected to the power storage unit,   wherein the second transistor is configured to adjust the amount of current flowing through the power storage unit, and   wherein the third transistor is configured to adjust the amount of current flowing through the power storage unit.   
     
     
         3 . The power storage device according to  claim 2 ,
 wherein the control circuit is configured to control the conduction states of the first transistor, the second transistor, and the third transistor.   
     
     
         4 . The power storage device according to  claim 2 ,
 wherein the control circuit is configured to monitor the state of charge of the power storage unit.