Method and device for charging and heating at low temperature a sealed storage cell battery

• US 4,025,861 A
• Filed: 07/29/1975
• Issued: 05/24/1977
• Est. Priority Date: 08/23/1974
• Status: Expired due to Term

• Current Assignee: Saft-Societe Des Accumulateurs Fixes et de Traction
• Original Assignee: Saft-Societe Des Accumulateurs Fixes et de Traction
• Inventors: Godard, Pierre, Prevot, Claude
• Primary Examiner(s): Hickey, Robert J.
• Application Number:
  US05/599,965
• Time in Patent Office: 665 Days
• Field of Search: 320/23, 320/24, 320/35, 320/36, 320/39, 320/40, 320/2, 320/5, 320/22, 320/32, 320/33
• US Class Current: 320/152
• CPC Class Codes: H02J 7/007194 of the battery
• CPC Class Codes: Y10S 320/22 Line impedance, e.g. resistor

Abstract

Method for charging a sealed storage cell battery according to which the battery is heated when its temperature lies below a determined value and the intensity of the charge current is lowered by being shunted to heat the battery when the voltage of the battery reaches a given value, characterized in that the said value of the voltage of the battery supplies the signal which causes the heating of the battery; and device for implementing the method.

Claims

1. Method for charging a sealed storage battery according to which the battery is heated when its temperature is situated below a determined value and the intensity of the charge current to the battery is reduced by shunting part thereof when the battery voltage reaches a predetermined given value which is selected such that it can be attained as a battery voltage only when the battery temperature is at 0°

C. or lower and whose value is higher than end of charge voltage of the battery at average 20°

C. temperature, characterized in that the said value of the battery voltage supplies the signal which starts said shunting to effect the heating of the battery.

2. Method for charging according to claim 1, characterized in that said reduction in the charge current to the battery is obtained by shunting of part of the charge current and control of battery heating is effected by the intensity of the shunted current.

3. Method for charging according to claim 2, characterized in that the said shunted part of said charge current is used for effecting at least partly the heating of the battery.

4. Method for charging a sealed storage battery comprising the steps of supplying charge current to said battery, providing a shunt circuit for said charge current, heating said battery with charge current and at least in part by current in said shunt circuit when the internal temperature of said battery lies below a predetermined value, sensing battery voltage and effecting shunting of charge current into said circuit and thereby lowering the intensity of the charge current supplied to the battery when the battery voltage attains a predetermined given value which is selected such that it can be attained as a battery voltage only when the temperature of the battery is at 0°

C. or lower and whose value is higher than end of charge voltage of the battery at average 20°

C. temperature, and utilizing the said predetermined battery voltage value to cause said shunting of charge current into said shunt circuit and utilizing the intensity of the shunted current to control the internal heating of said battery.

5. Method for charging a sealed storage battery according to claim 4 characterized in that shunting of any of said charge current into said shunt circuit effects lowering of the intensity of charge current to said battery and controlling the extent of heating of said battery by the intensity of the shunted charge current.

6. Method for charging a sealed storage battery according to claim 5 wherein said shunted charge current serves to effect at least partly the heating of said battery.

7. A battery charging system for a sealed storage battery comprising means for supplying a direct charging current connected in series to said storage battery, heating means for said battery, a shunt circuit for said charging current connected in parallel with said battery and means dependent upon a predetermined battery voltage occurring at 0°

C. or lower for effecting shunting of charging current into said shunt circuit, means for effecting energization of said heating means for said battery with charging current controlled by intensity of shunted current in said shunt circuit, and means sensitive to the intensity of shunted charging current flowing in the shunt circuit to control energization of said battery heating means including means for energizing said heating means for a given value of intensity of the shunted charging current flowing in the shunt circuit and for deenergizing said heating means when said intensity is lower than said given value.

8. A battery charging system for a sealed storage battery according to claim 7 wherein said shunted charging current is at least partially used to heat said battery.

9. A battery charging device for a sealed storage battery comprising a current charger connected in series with the battery, a shunt circuit and a battery voltage sensitive means connected in parallel across said battery, a heating circuit for the battery and a current sensor means with two thresholds connected in parallel across said charger and battery, said sensor means also being connected to said voltage sensitive means, said battery voltage sensitive means being responsive to battery voltage to shunt charge current into said shunt circuit when said voltage reaches a given value and said current sensor means being responsive to intensity of current shunted into said shunt circuit when the internal temperature of the battery lies below a given value to effect flow of heating current in said heating circuit and to cut off flow of heating current in said heating circuit above said last-named value.

10. A battery charging device for a sealed storage battery according to claim 9 including a heating resistor in said heating circuit and wherein said shunt circuit becomes heated upon passage of shunted current therethrough, and means to add the heat then occurring in said shunt circuit to the heat provided by said heating resistor when heating current flows through said resistor.

11. A battery charging device for a sealed storage battery according to claim 9 including means for regulating input voltage to said current charger.