LEAD STORAGE BATTERY CELL ELECTROLYTE DENSITY MEASURING DEVICE AND METHOD

• US 3,684,950 A
• Filed: 02/08/1971
• Issued: 08/15/1972
• Est. Priority Date: 02/08/1971
• Status: Expired due to Term

• Current Assignee: Ove K-G Nilsson
• Original Assignee: Ove K-G Nilsson
• Inventors: Nilsson, Ove K-G
• Primary Examiner(s): Smith, Alfred E.
• Application Number:
  US05/113,361
• Time in Patent Office: 554 Days
• Field of Search: 324/29.5,29 136/182
• US Class Current: 324/432
• CPC Class Codes: G01N 27/07 Construction of measuring vessels; Electrodes therefor
• 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 measurement of the charge in a lead-acid storage battery through the determination of the density of the sulfuric acid electrolyte by making two conductivity measurements of the electrolyte with the second measurement being made after a dilution or concentration of the sulfuric acid to thereby resolve an ambiguity in the conductivity-density relationship.

Claims

1. Apparatus for determining the charge in a cell of a lead-acid storage battery having a sulfuric acid electrolyte comprising a tube of electrolyte resistant insulating material disposed substantially vertically in the cell and submerged in said electolyte;

means for generating gas bubbles which fill the cross section of said tube and rise to the top of said tube at a controlled rate and at arbitrarily selectable intervals of time;

a pair of opposed electrodes on opposite sides of said tube above the bubble generating means; and

circuit connections between said pair of opposed electrodes and means for producing an indication of the conductivity of said electrolyte.

2. Apparatus as defined in claim 1 together with means for varying in a known direction the density of a portion of the electrolyte passing between said pair of opposed electrodes and for producing an indication of the conductivity of said portion of the electrolyte.

3. Apparatus as defined in claim 2 wherein the density varying means comprises a battery cell having electrodes on opposed sides of the inner surface of said tube, said cell electrodes being located below said pair of opposed electrodes but above said gas bubble generating means.

4. Apparatus as defined in claim 3 wherein said cell is disconnected for a portion of each measuring cycle and is selectively connected to cause the density of the electrolyte in the region of the cell to be altered in a known direction.

5. Apparatus as defined in claim 3 further comprising another pair of opposed electrodes on opposite sides of said tube above the bubble generating means and below said cell, and said cell is continuously connected during each measuring cycle whereby the conductivity of a portion of the electrolyte at said other pairs of electrodes is first measured, the density of said electrolyte portion altered in a known direction as said portion rises past said cell electrodes, and the conductivity of said portion whose density has been altered is measured to produce a determinable measurement of the density of the battery electrolyte.

6. Apparatus for use with a lead-storage battery in making a determination of the density of sulfuric acid electrolyte within said battery comprising:

a tube of electrolyte resistant insulating material adapted to be disposed substantially vertically in a cell of the battery;

means for producing gas bubbles that fill the inside diameter of said tube at arbitrarily selectable intervals of time and rise to pass through said tube;

means on said tube for providing a measurement of the conductivity of the electrolyte passing through said tube between successive gas bubbles;

a pair of elements constituting a battery cell for seLectively altering the density of said electrolyte on said tubing a position below said measurement means, and means for connecting said measurement means to a remote measuring instrument.

7. Apparatus as defined in claim 6 having a second means on said tube for providing a measurement of the conductivity of the electrolyte passing through said tube, said second measurement means being disposed below said battery cell elements.

8. A method for producing a measurement of the density of the electrolyte in a lead-acid storage battery comprising providing a tube which is disposed in a substantially vertical position submerged in the electrolyte of a cell of said battery;

generating bubbles of gas which fill the cross section of said tube and rise through said tube at arbitrarily selectable intervals of time;

measuring the conductivity of the electrolyte as it passes through an upper region of said tube;

thereafter altering the density of a portion of said electrolyte in said tube in a known direction and again measuring the conductivity of said altered portion as it passes through said tube to thereby provide a determination of the electrolyte density.

9. The method as defined in claim 8 wherein the step of altering the density of a portion of said electrolyte comprises passing the electrolyte through a region of said tube containing electrodes producing the charging or discharging action of a battery cell on the electrolyte passing through said tube.

10. The method as defined in claim 9 wherein a first conductivity measurement is made in the tube at a region below said density altering region and a second conductivity measurement is made in the tube at a region above said density altering region.