BATTERY CHARGER AND METHOD UTILIZING ALTERNATING DC CHARGING CURRENT

• US 20150155733A1
• Filed: 12/17/2014
• Published: 06/04/2015
• Est. Priority Date: 07/15/2005
• Status: Active Grant

• Current Assignee: Schumacher Electric Corporation
• Original Assignee: Schumacher Electric Corporation
• Inventors: Johnson, Thomas Finis, Whiting, John S., Waldron, John F.
• Granted Patent: US 9,450,435 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H02J 5/00 Circuit arrangements for transfer of electric power between ac networks and dc networks H02J3/36 takes precedence
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/0045 concerning the insertion or the connection of the batteries
• CPC Class Codes: H02J 7/00711 with introduction of pulses during the charging process
• CPC Class Codes: H02J 7/02 for charging batteries from ac mains by converters

Abstract

A battery charger is disclosed for use with various batteries, such as automotive- and marine-type batteries. In accordance with an aspect of the invention, the charging current is alternated between non-zero DC charging current levels. By alternating the charging current between non-zero DC charging levels, the battery can be charged to a higher capacity (i.e., ampere hours) faster, thus reducing the charging time and at the same time allow the rating of the battery charger to be increased. In accordance with another important aspect of the invention, the technique for alternating the charging current can be implemented in both linear- and switched-mode battery chargers.

Claims

1. A battery charger comprising:

a microprocessor-controlled battery charging circuit, said microprocessor controlled battery charging circuit being configured to provide a battery charging current for charging a battery,

wherein said microprocessor-controlled battery charging circuit (a) repeatedly measures a battery voltage of said battery while said battery is being charged by an AC input source that defines an AC zero crossing and (b) provides (i) a first charging cycle while the battery voltage is less than a predetermined voltage and (ii) a second charging cycle while the battery voltage is greater than or equal to said predetermined voltage,

wherein said first charging cycle comprises two DC charging values, each having a non-zero average DC value defining a maximum charging current value and a minimum charging current value, said microprocessor-controlled battery charging circuit alternating the battery charging current between said maximum charging current value and said minimum charging current value until said battery voltage reaches said predetermined voltage, said maximum charging current value and said minimum charging current value being selected to cause said battery to be at least partially charged during said first charging cycle.