Method of charging a vehicle battery

• US 4,308,492 A
• Filed: 10/24/1979
• Issued: 12/29/1981
• Est. Priority Date: 10/24/1978
• Status: Expired due to Term

• Current Assignee: Nippondenso Co., Ltd. (DENSO Corporation)
• Original Assignee: Nippondenso Co., Ltd. (DENSO Corporation)
• Inventors: Mori, Kazumasa, Muto, Katsuya, Kato, Tetsuo, Miura, Etsushi
• Primary Examiner(s): Hickey, Robert J.
• Application Number:
  US06/088,055
• Time in Patent Office: 797 Days
• Field of Search: 320/31, 320/32, 320/35, 320/36, 320/39, 320/43, 320/48, 320/64, 320/68, 322/24, 322/25, 322/28, 322/33, 322/34, 322/22, 322/23
• US Class Current: 322/28
• CPC Class Codes: H02J 7/00304 Overcurrent protection
• CPC Class Codes: H02J 7/00308 Overvoltage protection
• CPC Class Codes: H02J 7/0047 with monitoring or indicating devices or circuits
• CPC Class Codes: H02J 7/1438 in combination with power supplies for loads other than batteries
• CPC Class Codes: H02J 7/16 Regulation of the charging current or voltage by variation of field

Abstract

A new method of charging a vehicle battery is disclosed. The proposed method employs electronically controlled data processing device, which controls battery charging condition in accordance with temperature, battery electrolyte, external electric load as well as battery voltage. As a result, voltage drop due to over loading may be prevented and a stable battery charging voltage may be obtained.

Claims

1. A method of charging a vehicle battery comprising the steps of:

detecting the actual charging voltage produced by a generator connected for charging the battery, the temperature of the battery, a parameter representative of the battery charging condition and the battery load current, deriving regulated voltage values which are functions of one or more of the battery operating temperature, the parameter representative of the battery charging condition and the battery load current, obtaining an optimum voltage value corresponding to the battery voltage, temperature of the battery, battery charging condition and battery load current in accordance with the predetermined regulated voltage values, comparing the said battery charging voltage with the said optimum voltage value, and controlling operation of the generator in accordance with the result of the said comparison to adjust the battery charging voltage to the said optimum voltage value.

2. A method according to this claim 1, wherein the said temperature is temperature of battery electrolyte and the parameter representative of the battery charging condition is the specific gravity of the battery electrolyte.

3. A method according to claim 1 further comprising the steps of generating an alarm when the generator is not operating.

4. An apparatus for controlling a vehicle alternator used to charge a vehicle battery and having a field winding, Y-connected armature windings for generating an alternating current voltage in accordance with the energization of said field winding, and a rectifier circuit for rectifying said alternating current voltage to produce a direct current charging voltage, said apparatus comprising:

means for detecting a power supply condition from said vehicle battery to vehicle electric loads;

means for detecting the temperature of said battery;

means for detecting the specific gravity of electrolyte of said battery;

means for establishing a desired value of said charging voltage in accordance with said detected power supply condition, said detected temperature and said detected specific gravity, said desired value being increased in accordance with the increase in said detected power supply and with the decreases of said detected temperature and said detected specific gravity;

means for detecting an actual value of said charging voltage applied to said vehicle battery;

means for detecting a neutral point voltage of said Y-connected armature windings;

means for comparing said detected neutral point voltage with a predetermined reference value;

means for energizing said field winding of said vehicle alternator at a fixed frequency when the output of said comparing means indicates that said detected neutral point voltage is smaller than said predetermined reference value; and

means for energizing said field winding of said vehicle alternator as long as said actual value of said charging voltage is smaller than said desired value of said charging voltage when the output of said comparing means indicates that said detected neutral point voltage is larger than said predetermined reference value.