Battery management and equalization system for batteries using power line carrier communications

• US 7,471,066 B2
• Filed: 12/22/2005
• Issued: 12/30/2008
• Est. Priority Date: 12/22/2004
• Status: Active Grant

• Current Assignee: Power Technology Holdings LLC
• Original Assignee: Odyne Corporation
• Inventors: Ambrosio, Joseph Mario, Sfakianos, Konstantinos
• Primary Examiner(s): Ullah; Akm E
• Assistant Examiner(s): TORRES RUIZ, JOHALI ALEJANDRA
• Application Number:
  US11/315,927
• Publication Number:
  US 20060132089A1
• Time in Patent Office: 1,104 Days
• Field of Search: 320/109, 320/110, 320/111, 320/112, 320/119, 320/124, 320/150, 320/152, 320/157, 320/160, 320/162
• US Class Current: 320/119
• CPC Class Codes: H02J 7/0014 Circuits for equalisation of charge between batteries
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A battery charging system uses power line carrier communications, for communicating battery state information associated with charging batteries, between a battery charger and a battery management system (BMS) located on the battery or battery pack. The power line carrier includes transmitters and receivers transmitting and receiving battery state information, such as current, voltage and temperature, as digital signals on existing cable conductors located between the battery/battery pack and the battery charger. The battery management system (BMS), which is physically located on the battery pack, receives the information from the power line carrier, in order to measure a variety of parameters relating to charging the battery, which may be a motor vehicle battery or a battery for operating machinery, such as fork lifts, bulldozers and other earth moving and product transportation vehicles.

Claims

1. A battery charging system comprising:

at least one battery pack having positive and negative terminals;

a bulk battery charger having a pair of DC charging wires to said positive and negative terminals for delivering charging current to said at least one battery pack;

an AC or DC power source for said bulk battery charger;

a battery management system in said battery pack for controlling said at least one bulk battery charger connected directly to said positive and negative terminals and having means for monitoring relevant state conditions of said battery pack;

said at least one battery pack being a plurality of batteries in a battery pack, each said battery having a measurement and equalization node communicating with an equalization power supply providing auxiliary power directly to each said battery node when said battery management system determines said battery pack is deficient in charge and while said bulk battery charger is charging said batteries; and

,

an equalization power supply controlled by said battery management system for supplying said auxiliary power to each said battery node.

2. The battery charging system of claim 1 wherein measurement and equalization nodes are expandable to match a predetermined number of said batteries in said battery pack.

3. The battery charging system as in claim 1 wherein said equalization power supply communicates via a bus, carrying a charging voltage compatible with said at least one battery, when said at least one battery is deficient in charge.

4. The battery charging system as in claim 1 wherein said battery management system includes an isolated communications cable located between said battery management system and said bulk charger;

said battery management system further having an output data line providing battery state data including at least one of battery pack voltage, current, and overall state of charge, said data being displayed to a driver of a vehicle having said battery charging system.

5. The battery charging system as in claim 1 wherein said AC or DC source is on-board a vehicle having said battery charging system.

6. The battery charging system as in claim 1 wherein said bulk battery charger has built-in intelligence communicating bi-directionally over said cable with said battery management system.

7. The battery charging system as in claim 6 wherein said battery management system sends charge current setting request signals based upon algorithms appropriate to battery chemistry to said bulk charger, while said battery charger responds with requested current and/or with other charger parameters which said battery management system interprets to insure a selected algorithm is being followed.

8. The battery charging system as in claim 7 wherein an appropriate charge current setting sent by said bulk battery management system to said bulk battery charger is based upon algorithms appropriate to real-time chemistry of said at least one battery.

9. The battery management system of claim 1 wherein a current measurement device measures current being supplied to a load and/or current received from said battery charger to said plurality of batteries, wherein said measured current information is sent to said battery management system, wherein said battery management system compares actual current to a current signal sent to said battery charger.

10. The battery charging system as in claim 2 wherein each said measurement and isolation node for each said battery includes an isolated communications line, each said measurement and isolation node being daisy-chained to all of each other said measurement and equalization nodes in said battery pack, said isolated communications line providing operating data on each said battery to said battery management system,

said isolated communications line sending at least one equalization signal to a particular node of a respective battery, to connect or disconnect said at least one battery to said equalization bus, which said bus carries a charging voltage compatible with a single battery requiring said charging voltage.

11. The battery charging system as in claim 1 wherein said equalization power supply is controlled by said battery management system and said equalization power supply is powered by at least one of AC power, external DC power and/or internal DC power derived from terminal voltage of said battery pack.

12. The battery charging system as in claim 1 wherein said system is connected to one battery at a time depending on battery condition as determined by said battery management system, based on information from a corresponding equalization and measurement node of said at least one battery and recent historical data of said at least one battery.

13. The battery charging system as in claim 12 wherein said measurement and equalization node includes a measurement section accepting temperature readings from a temperature probe and voltage readings from voltage sensor lines connected to respective battery leads leading to terminals of said at least one battery.

14. The battery charging system as in claim 3 further comprising a relay within each said measurement and equalization node communicating with said equalization power supply bus.

15. The battery charging system as in claim 14 wherein when said relay is energized, equalization current flows from said bus to said terminals of said at least one battery.

16. The battery charging system as in claim 1 wherein said equalization power supply achieves equalization through identification of respective capacity deficient batteries by said battery management system with additional charge being provided from said equalization power supply directly to a respective deficient battery, said battery management system controlling sequence and duration of equalization of said at least one battery, based on a predetermined equalization algorithm appropriate to the chemistry of said at least one battery.

17. The battery charging system as in claim 1 wherein by controlling said equalization power supply, said battery management system charges different batteries at different rates and/or tapers respective charging current.

18. The battery charging system as in claim 1 wherein said battery charger includes a power section and a control section, said control section containing a power line carrier modem with a transceiver chip contained therein.

19. The battery charging system as in claim 1 wherein said battery pack includes a battery compartment and said battery management system as a separate compartment,

said battery management system having a corresponding power line carrier modem with a power line carrier transceiver chip,

said power line carder modem providing an interface between respective data sections in said battery management system and/or said battery charger control section and said chip transceivers modulating said data being transferred back and forth over said pair of DC charging wires connected between said bulk battery charger and at least one battery.

20. A battery charging system comprising:

rechargeable batteries arranged in a pack having positive and negative terminals;

a bulk battery charger having a pair of DC charging wires to said positive and negative terminals for delivering charging current to said batteries;

an AC or DC power source for said bulk battery charger;

a battery management system within said pack of rechargeable batteries for controlling said bulk battery charger connected to said positive and negative terminals having means for monitoring relevant state conditions of said batteries; and

a DC equalization bus circuit for said batteries, said circuit being powered from a central equalization power supply and being connected to said batteries via a measurement and equalization node associated with each battery, said node providing a direct connection to a DC equalization bus through a switching network charging said batteries to equalize all said batteries to reach an equal state of capacity;

said DC equalization bus circuit being powered by said equalization power supply operating during bulk charging of said at least one battery, said DC output of said equalization power supply being matched to a predetermined voltage range of an individual battery within a series or series-parallel string of said plurality of batteries.

21. The battery charging system as in claim 20 wherein said DC equalization bus is energized by at least one of:

a) A DC to DC converter reducing the total voltage of said plurality of batteries to a voltage of an individual battery.

b) An AC to DC power supply using locally available AC mains and providing appropriate voltage to charge said at least one battery.

22. The battery charging system of claim 21 wherein

electrically isolated voltage and temperature measurement is measured by at least one of:

a) an isolated communication network based on CAN (Controller Area Network);

b) a nodal system including an electrically isolated voltage and temperature measurement device on each said battery; and

,

c) a common DC power bus connected to a central power supply which is adequate to charge a single battery cell of said plurality of batteries, a respective node located on each said battery cell being connected in parallel with said DC power bus in order to add power to each said at least one battery as required.