System and method for monitoring electrolyte levels in a battery

• US 7,812,613 B2
• Filed: 06/14/2004
• Issued: 10/12/2010
• Est. Priority Date: 06/12/2003
• Status: Active Grant

• Current Assignee: Philadelphia Scientific LLC (Philadelphia Scientific)
• Original Assignee: Philadelphia Scientific
• Inventors: Jones, Duncan, Worthingdon, John
• Primary Examiner(s): Tso; Edward
• Assistant Examiner(s): BOATENG, ALEXIS ASIEDUA
• Application Number:
  US10/866,862
• Publication Number:
  US 20050001628A1
• Time in Patent Office: 2,311 Days
• Field of Search: 320/112, 320/132, 324/425, 324/426, 324/429, 324/437, 429/89, 429/91, 429/61, 340/620
• US Class Current: 324/426
• CPC Class Codes: B66F 9/24 Electrical devices or systems
• CPC Class Codes: G01F 23/80 Arrangements for signal processing
• CPC Class Codes: H01M 10/484 for measuring electrolyte level, electrolyte density or electrolyte conductivity
• CPC Class Codes: H01M 50/569 Constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals battery terminal connectors with integrated measuring arrangements G01R31/364
• CPC Class Codes: H01M 6/505 Cells combined with indicating means for external visualization of the condition, e.g. by change of colour or of light intensity
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A measuring device is used in conjunction with a programmable controller for monitoring electrolyte levels in the battery. According to one implementation, the measuring device is located in a battery and is configured to detect when the electrolyte level in the battery falls below a particular level. The controller is in electrical communication with the electrolyte detection device. The controller is configured to: (i) receive a signal from the electrolyte level detection device indicating when the electrolyte level in the battery has fallen below the particular level; (ii) introduce a wait-period after the signal is received; and (iii) enable an indicator to indicate that the electrolyte level in the battery should be refilled when the wait-period expires.

Claims

1. A system for monitoring the electrolyte level in a battery having one or more separators between positive and negative plates in a cell of the battery, the one or more separators having a top which is at a level that is higher than a top of the plates, said system comprising:

a measuring device, suitable to be located in said battery, configured to detect when the electrolyte level in the battery falls below a first level which is above the tops of the separators in said battery; and

a controller, in electrical communication with the measuring device, configured to (i) receive a signal from the measuring device indicating when the electrolyte level in the battery has fallen below said first level, (ii) introduce a wait-period after the signal is received, and (iii) enable an indicator to indicate that the electrolyte in the battery should be refilled after the wait-period expires;

wherein said wait-period represents an appropriate time it takes the electrolyte level to fall from said first level to a second level which is below the tops of said separators and above the tops of said plates.

2. The system as recited in claim 1, wherein during the wait-period the controller is further configured to enable the indicator to indicate that the electrolyte level in the battery is approaching said second level as a forewarning to actually providing the indication that the electrolyte level in the battery should be refilled.

3. The system as recited in claim 1, wherein the wait-period is a programmable period of time.

4. The system as recited in claim 1, wherein the controller comprises a counter configured to count down a programmable period of time comprising the wait-period.

5. The system as recited in claim 1, wherein the controller comprises a charging-cycle module configured to monitor the number of cycles of charging the battery experiences after said signal is received and wherein said wait-period is a function of said number of cycles of charging.

6. The system as recited in claim 1, wherein the controller comprises a water-loss estimation module, configured to estimate a rate of electrolyte loss for the battery as a function of the age of the battery, and adjust the wait-period accordingly.

7. The system as recited in claim 1, wherein the indicator is one or more lights that are activated to signify that the electrolyte level in the battery should be refilled.

10. The system as recited in claim 1, further comprising:

means for receiving the signal from the measuring device indicating whether the electrolyte level in the battery is above or below the measuring device; and

means for repetitively energizing and de-energizing the measuring device over time.

11. The system as recited in claim 10, wherein the means for repetitively energizing and de-energizing the measuring device over time comprises the controller.

12. The system as recited in claim 10, wherein the means for receiving the signal from the measuring device is an input terminal of the controller.

8. A battery, comprising:

one or more cells having disposed therein positive and negative plates, a separator disposed between said positive and negative plates, and a liquid electrolyte within said cells having an electrolyte level, said separator having a top which is at a level above a top of said positive and negative plates;

a probe, located in at least one of said battery cells, configured to detect when said electrolyte level falls below a first level which is above the tops of said separators;

an indicator; and

a controller, in electrical communication with the probe, configured to (i) receive a signal from the probe indicating when the electrolyte level in the battery has fallen below said first level, (ii) introduce a wait-period after the signal is received, and (iii) enable the indicator to signify that the electrolyte in the battery should be refilled when the wait-period expires;

wherein said wait-period is chosen to allow the electrolyte level to fall from said first level to a second level which is below the tops of said separators and above the tops of said positive and negative plates.

9. The battery as recited in claim 8, further comprising an electrical circuit connecting the controller to the probe, the electrical circuit configured to enable the signal to be sent to the controller when the probe detects that the electrolyte level is below said first level.

13. The battery as recited in claim 8, further comprising:

means for receiving the signal from the probe indicating whether the electrolyte level in the battery is above or below the probe; and

means for repetitively energizing and de-energizing the probe over time.

14. The battery as recited in claim 13, wherein the means for repetitively energizing and de-energizing the probe over time comprises the controller.

15. The battery as recited in claim 13, wherein the means for receiving the signal from the probe is an input terminal of the controller.

16. A system for monitoring the electrolyte level in a battery having one or more separators between positive and negative plates in a cell of the battery, the separator having a to that is at a level which is higher than a to of the plates, said system, comprising:

a measuring device for detecting when an electrolyte level in the battery falls below a first level which is above said top of said one or more separators, said measuring device comprising a probe positioned at said first level; and

a controller, in electrical communication with the measuring device, configured to (i) receive a signal from the measuring device indicating when the electrolyte level in the battery has fallen below said first level, (ii) introduce a wait-period after the signal is received, the wait-period being chosen to allow the electrolyte level to continue to fall to a second level which is below the tops of said separators and above the tops of said plates, and (iii) enable an indicator to indicate that the electrolyte in the battery should be refilled after the wait-period expires.

17. A system for monitoring the electrolyte level in a battery having a separator between positive and negative plates in a cell of the battery and a lowest recommended electrolyte level which is above the positive and negative plates, the separator having a top which is at a level that is higher than the lowest recommended electrolyte level, said system comprising:

a measuring device, located in said battery, configured to detect when the electrolyte level in the battery falls below a first level which is above the to of said separator;

a controller, in electrical communication with the measuring device, configured to (i) receive a signal from the measuring device indicating when the electrolyte level in the battery has fallen below the first level, (ii) introduce a wait-period after the signal is received, and (iii) enable an indicator to indicate that the electrolyte in the battery should be refilled after the wait-period expires; and

wherein said wait-period is chosen to allow the electrolyte level to fall from said first level to a second level which is below the top of said separator and no lower than said lowest recommended electrolyte level.