Battery electrolyte-level and electrolyte-stratification sensing system

• US 5,550,474 A
• Filed: 05/03/1985
• Issued: 08/27/1996
• Est. Priority Date: 05/03/1985
• Status: Expired due to Fees

• Current Assignee: Ernest A. Dahl
• Original Assignee: Ernest A. Dahl
• Inventors: Dahl, Ernest A.
• Primary Examiner(s): Issing, Gregory C.
• Application Number:
  US06/730,122
• Time in Patent Office: 4,134 Days
• Field of Search: 324/432, 324/437, 324/445, 429/90-93, 320/48, 73/32 R, 73/440, 73/446-448, 340/636
• US Class Current: 324/432
• CPC Class Codes: G01F 23/261 for discrete levels
• CPC Class Codes: G01F 23/703 using electromechanically actuated indicating means
• CPC Class Codes: H01M 10/484 for measuring electrolyte level, electrolyte density or electrolyte conductivity
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

The device uses a sensor probe in which a plurality of electrolyte level sensor coils and/or specific gravity stratification indicators are stacked vertically in the walls of a hollow electrically insulating and chemically nonreactive elongated probe housing such that the sensor coils never come into contact with the electrolyte. Balanced transformers or series resonant coils are used to sense changes in electrolyte level and/or changes in specific gravity at various respective levels to indicate stratification of electrolyte. The fields of the sensors are changed by the amount of electrolyte in the area of the sensor coils. These changes operate to produce signals that are read as digital or analog outputs.

Claims

1. In a battery wet cell monitoring system, an electrolyte level sensing device, comprising:

a. a probe housing of electrically insulating and electrolyte nonreactive material;

said probe housing being of suitable size and shape for extending into the electrolyte of a wet cell battery;

b. a plurality of electrical coils embedded within said probe housing at various predetermined levels and insulated from coming into contact with the battery cell electrolyte;

each of said plurality of electrical coils comprising three adjacent commonly-wound coils of a balanced transformer;

c. a pulse generator means connected to apply a signal to the center coil of each of said plurality of three commonly-wound transformer coils;

each of said plurality of three commonly-wound transformer coils being series connected such that the sum voltage is zero in air;

d. the output of each said balanced transformer being connected to a comparator and detector circuit, wherein, as said transformer coils are sequentially surrounded by electrolyte the change in the Q of the coils results in an increase in transformer voltage output, which output, when it exceeds a predetermined amount, causes said comparator and detection circuit to produce an output that indicates the presence of a predetermined amount of electrolyte;

e. read-out means connected to said detection circuit wherein indicator signals from said detection circuit are used to indicate the electrolyte level within the battery cell.

2. A battery electrolyte monitoring system as in claim 1 wherein a plurality of said balanced transformers together with said respective comparator and detector circuits are connected to an integrated circuit multiplexing switch for obtaining a simultaneous readout of a plurality of electrolyte levels being monitored.

3. A battery electrolyte monitoring system as in claim 1 wherein said respective indicator signals are fed to a data bus for remote read-out of said electrolyte levels being monitored and for controlling electrolyte conditions.

4. A battery electrolyte monitoring system as in claim 2 wherein said multiplexing switch provides analog output voltages connected to a common read-out and control means for monitoring any of a plurality of battery wet cells, for providing automatic control to add additional electrolyte to a wet cell as needed, and to provide circulation of electrolyte to eliminate stratification thereof when such occurs.

5. A battery electrolyte monitoring system as in claim 1 wherein a plurality of said balanced transformers together with said respective comparator and detector circuits are connected to an integrated circuit multiplexing switch for obtaining a simultaneous readout of a plurality of electrolyte levels being monitored.

6. A battery electrolyte monitoring system as in claim 5 wherein said multiplexing switch provides analog output voltages connected to a common read-out and control means for monitoring any of a plurality of battery wet cells, for providing automatic control to add additional electrolyte to a wet cell as needed, and to provide circulation of electrolyte to eliminate stratification thereof when such occurs.

7. A battery electrolyte monitoring system as in claim 1 wherein said probe housing is of acrylic plastic.

8. A battery electrolyte monitoring system as in claim 1 wherein said probe housing is of generally elongated shape and said electrical coils are located in a stacked arrangemenmt within said probe housing.

9. A battery electrolyte monitoring system as in claim 1 wherein a plurality of said monitor stytems are used for monitoring a bank of battery wet cells at a common readout location.

10. A battery electrolyte monitoring system as in claim 1 wherein respective indicator signals from each of said electrical coils are digitized and combined into a single analog level for transmitting information on a single monotoring system channel.

11. In a battery wet cell monitoring system, an electrolyte stratification sensing device, comprising:

a. a probe housing of electrically insulating and electrolyte nonreactive material;

said probe housing being hollow and of suitable shape for extending into the electrolyte of a battery wet cell;

said hollow probe housing being provided with a plurality of passageways therein to provide for efficient circulation of electrolyte therethrough;

b. a plurality of electrical coils embedded within said probe housing at various predetermined electrolyte depths and insulated from coming into contact with the battery cell electrolyte;

each of said plurality of electrical coils comprising three adjacent commonly-wound coils of a balanced transformer;

c. a pulse generator means connected to apply a signal to the center coil of each of said plurality of three commonly-wound transformer coils;

each of said plurality of three commonly-wound transformer coils being series connected such that the sum voltage is zero in air;

d. the output of each said balanced transformer being connected to a comparator and detector circuit, wherein, as said transformer coils are sequentially surrounded by electrolyte the change in the Q of the coils results in an increase in transformer voltage output, which output, when it exceeds a predetermined amount, causes said comparator and detection circuit to produce an output that indicates the presence of a predetermined amount of electrolyte;

e. a specific gravity float means associated with each said plurality of balanced transformers, respectively, and retained within said hollow probe housing;

each specific gravity float means being retained within said housing in a specific area for operation relative to its respective balanced transformer;

f. each specific gravity float means being operable to displace a predetermined amount of electrolyte such that when a float means moves to a location within the area of its respective balanced transformer the amount of electrolyte surrounding the balanced transformer is reduced (and vice versa) thereby causing a change in the Q of the transformer coils and resulting in a change in voltage across the coils;

g. read-out means connected to said detection circuit wherein indicator signals from said detection circuit are operable to indicate a change in electrolyte specific gravity at each respective electrolyte depth within the battery cell.

12. A battery electrolyte monitoring system as in claim 11 wherein said respective indicator signals are fed to a data bus for remote read-out of said electrolyte levels being monitored and for controlling electrolyte conditions.

13. A battery electrolyte monitoring system as in claim 11 wherein each of said specific gravity floats is of the same density.

14. A battery electrolyte monitoring system as in claim 11 wherein each of said specific gravity floats is of a different density allowing the monitoring system to operate for measuring specific gravity of the battery cell electrolyte over a predetermined range of values.

15. A battery electrolyte monitoring system as in claim 11 wherein said probe housing is of acrylic plastic.

16. A battery electrolyte monitoring system as in claim 11 wherein said probe housing is of generally elongated shape and said balanced transformer coils are located in a stacked arrangement within said probe housing.

17. A battery electrolyte monitoring system as in claim 11 wherein a plurality of said monitor systems are used for monitoring a bank of battery wet cells at a common readout location.

18. A battery electrolyte monitoring system as in claim 11 wherein respective indicator signals from each of said balanced transformers are digitized and combined into a single analog level for transmitting information on a single monitoring system channel.