CHARGING METHOD, BATTERY PACK AND CHARGER FOR BATTERY PACK
1 Assignment
0 Petitions
Accused Products
Abstract
A charging method includes a constant-current charging step wherein a constant charge current is supplied to a secondary battery to be charged to a predetermined end voltage; and a constant-voltage charging step wherein the predetermined end voltage is maintained by reducing the charge current after said secondary battery is charged to the end voltage, wherein: said constant-current charging step includes the charging step to be carried out with the end voltage set to OCV which is a voltage when no current is flowing, and with a voltage of a charge terminal of said battery pack set to an overvoltage above said OCV, and said constant-voltage charging step includes the step of reducing the voltage across the charge terminals to the after the voltage across the charge terminals is increased to the overvoltage or after the charge current of the charge terminal is reduced to or below a predetermined current level.
83 Citations
22 Claims
-
1-11. -11. (canceled)
-
12. A charging method, comprising:
-
a constant-current charging step wherein a constant charge current is supplied to a secondary battery to be charged to a predetermined end voltage; and a constant-voltage charging step wherein the predetermined end voltage is maintained by reducing the charge current after said secondary battery is charged to the end voltage, wherein; said constant-current charging step includes a charging step to be carried out with the end voltage set to an open circuit voltage (OCV) which is a voltage when no current is flowing, and with a voltage across charge terminals of said battery pack set to an overvoltage above the OCV, and said constant-voltage charging step includes a step of reducing the voltage across the charge terminals to the OCV after the voltage across the charge terminals is increased to the overvoltage or after the charge current across the charge terminals is reduced to or below a predetermined current level. - View Dependent Claims (13, 14)
-
-
15. A battery pack, comprising:
-
a secondary battery; a current detector which detects a charge current of said secondary battery; a communicator which communicates with a charger; and a charge controller which carries out a constant-current charging wherein a constant charge current is supplied to said secondary battery to be charged to a predetermined end voltage by sending a request for a charge voltage and a charge current to the charger via said communicator and which carries out a constant-voltage charging wherein the end voltage is maintained by reducing the charge current after said secondary battery is charged to the end voltage, wherein said charge controller sets the end voltage to an OCV, which is a voltage when no current is flowing, and requests said charger via said communicator, i) for a charge voltage with which the voltage across the charge terminals can be increased to an overvoltage above the OCV when carrying out said constant-current charging, and ii) for a charge voltage with which the voltage across the charge terminals can be maintained at the OCV after the voltage across the charge terminals reaches the overvoltage and the current detector detects that the charge current is reduced to or below a predetermined current level. - View Dependent Claims (16, 17, 18, 19)
-
-
20. A charger, comprising:
-
a charge current supply circuit which supplies a charge current to a battery pack; a communicator which communicates with said battery pack; and a charge controller which carries out a constant-current charging wherein a constant charge current is supplied to a secondary battery of the battery pack to be charged to a predetermined end voltage by controlling a charge current from said charge current supply circuit in response to a request from said battery pack inputted via said communicator and which carries out a constant-voltage charging by reducing the charge current so as to maintain the end voltage after said second battery is charged to the end voltage, wherein when the constant-current charging is to be carried out, said charge controller sets the end voltage to an OCV, which is a voltage when no current is flowing, in response to a request from said battery pack inputted via said communicator, and controls said charge current supply circuit so as to output such charge current that the voltage across the charge terminals of said battery pack becomes higher than the OCV, and when the voltage across the charge terminals reaches the overvoltage, and a transition is made from the constant-current charging to the constant-voltage charging, or when the charge current across the charge terminals is reduced to or below a predetermined current level, said charge controller controls said charge current supply circuit so as to reduce the voltage across the charge terminals to the OCV and to supply such a charge current to maintain the voltage across the charge terminals at the OCV. - View Dependent Claims (21, 22)
-
Specification