Sealed lead-acid cells and batteries having internal and external restraint for accommodating plate growth

Abstract

Sealed lead-acid cells are disclosed which include an internal cell restraint contacting the interior surface of the cover and positioned between the positive plates and the cover, the internal cell restraint cooperates with an external cell restraint, such as a coated metal face plate, to direct positive plate growth which occurs in service away from the cover, the features disclosed allowing plastic-to-plastic terminal post-cover seals to be used and allow cells of capacities of up to 2,000 Ampere Hours or more to be provided.

I claim:  
     
       1. A sealed lead-acid cell assembly in which the lead-acid cell is subject to positive grid growth during service comprising a cell support structure capable of housing at least one sealed lead-acid cell, a cell container sized to accommodate a cell element, a cell element positioned in said cell container and comprising a plurality of positive and negative plates and an absorbent separator positioned between adjacent plates, a cover sealed to said container and having an exterior and an interior surface, at least one positive terminal sealed to said cover and at least one negative terminal sealed to said cover, each of said positive and negative plates having at least one lug, a positive strap electrically connecting the lugs of the respective positive plates together, a negative strap electrically connecting the lugs of said negative plates together, the positive strap being electrically connected to the positive terminal and the negative strap being connected to the negative terminal, an internal restraint contacting the interior surface of the cover and positioned between said positive plates and said cover, an external restraint connected to said cell support structure and in contact with the exterior surface of the cover and said external and internal restraints directing the positive grid growth in service in a direction away from the internal  interior surface of said cover. 
     
     
       2. The cell assembly of  claim 1  wherein the cover is plastic, the positive and negative terminals comprise an electrically conductive metal material having plastic surrounding said metal material and said terminals having been heat sealed to provide a terminal-cover seal. 
     
     
       3. The cell assembly of  claim 2  wherein said heat-sealed cover has an open area about the terminal and a hot melt adhesive being contained in said open area. 
     
     
       4. The cell assembly of  claim 3  wherein said hot melt adhesive and at least the portion of said cover surrounding said hot melt adhesive each are colored the same. 
     
     
       5. The cell assembly of  claim 4  wherein the positive terminal is colored red, the negative terminal is colored black, and said cover is gray. 
     
     
       6. The cell assembly of  claim 1  wherein said cell support structure is a tray. 
     
     
       7. The cell assembly of  claim 1  wherein said cell support structure is a rack. 
     
     
       8. The cell assembly of  claim 1  wherein said cell support structure is a cabinet. 
     
     
       9. The cell assembly of  claim 1  wherein the container has a bottom having an internal bottom surface, said negative plates have at least two spaced feet contacting said internal bottom surface, said negative plates being otherwise spaced from said bottom interior  internal surface, and said positive plates being dimensioned such that said positive plates are spaced from the internal bottom surface of said container a distance sufficient to allow positive plate growth in service to occur and, when said cell is positioned in an upright manner, said cell element is sufficiently compressed in said container such that the positive plates are held in alignment with frictional force. 
     
     
       10. The cell of  claim 1  in which each of said positive and negative plates has at least two lugs and said cell has an electrical capacity of at least 2,000 Ampere Hours. 
     
     
       11. The cell assembly of  claim 10  wherein each positive and negative plate has at least two lugs and said cell has an electrical capacity of at least about 3,000 Ampere Hours. 
     
     
       12. The cell assembly of  claim 1  wherein said positive and negative plates have a height to width ratio of less than 2:1. 
     
     
       13. The cell assembly of  claim 1  wherein said separator comprises at least one layer of a single piece of material wrapped about said positive and negative plates in a serpentine fashion. 
     
     
       14. The cell assembly of  claim 1  wherein said separator is positioned between and about said positive and negative plates in a double U-wrap configuration. 
     
     
       15. The cell assembly of  claim 1  wherein said exterior plate  external restraint comprises a metallic face plate positioned on the exterior surface of the cover and attached to said cell support structure. 
     
     
       16. The cell assembly of  claim 1  wherein said internal plate restraint comprises a plastic insert resting on said positive plate strap when said cell is in an upright position and having an opening allowing electrical connection between said positive strap and positive terminal to be made. 
     
     
       17. A sealed lead-acid cell in which the lead-acid cell is subject to positive grid growth during service comprising a cell support structure capable of housing at least one sealed lead-acid cell, a cell container sized to accommodate a cell element, a cell element positioned in said cell container and comprising a plurality of positive and negative plates and an absorbent separator positioned between adjacent plates, a cover sealed to said container and having an exterior and an interior surface, at least one positive terminal sealed to said cover and at least one negative terminal sealed to said cover, each of said positive and negative plates having at least one lug, a positive strap electrically connecting the lugs of the respective positive plates together, a negative strap electrically connecting the lugs of said negative plates together, the positive strap being electrically connected to the positive terminal and the negative strap being connected to the negative terminal, and an internal restraint contacting the interior surface of the cover and positioned between said positive plates and said cover, and said internal restraint, cooperating in service, with an external cell restraint to direct movement caused by positive grid growth in service in a direction away from the internal  interior surface of said cover. 
     
     
       18. The sealed lead-acid cell of  claim 17 , wherein the cover is plastic, the positive and negative terminals comprise an electrically conductive metal material having plastic surrounding said metal material and said terminals having been heat sealed to provide a terminal-cover seal. 
     
     
       19. The sealed lead-acid cell of  claim 18  wherein said heat-sealed cover has an open area about the terminal and a hot melt adhesive being contained in said open area. 
     
     
       20. The sealed lead-acid cell of  claim 19  wherein said hot melt adhesive and at least the portion of said cover surrounding said hot melt adhesive each are colored the same. 
     
     
       21. The sealed lead-acid cell of  claim 20  wherein the positive terminal is colored red, the negative terminal is colored black, and said cover is gray. 
     
     
       22. The sealed lead-acid cell of claim  17   1 , wherein the container has a bottom having an internal bottom surface, said negative plates have at least two spaced feet contacting said internal bottom surface, said negative plates being otherwise spaced from said internal bottom interior  surface, and said positive plates being dimensioned such that said positive plates are spaced from the internal bottom surface of said container a distance sufficient to allow positive plate growth in service to occur and, when said cell is positioned in an upright manner, said cell element is sufficiently compressed in said container such that the positive plates are held in alignment with frictional force. 
     
     
       23. The sealed lead-acid cell of  claim 17 , in which each of said positive and negative plates has at least two lugs and said cell has an electrical capacity of at least 2,000 Ampere Hours. 
     
     
       24. The sealed lead-acid cell of  claim 23  wherein each positive and negative plate has at least two lugs and said cell has an electrical capacity of at least about 3,000 Ampere Hours. 
     
     
       25. The sealed lead-acid cell of  claim 17  wherein said separator comprises a single piece of material wrapped about said positive and negative plates in a serpentine fashion. 
     
     
       26. The sealed lead-acid cell of  claim 17  wherein said separator is positioned between and about said positive and negative plates in a double U-wrap configuration. 
     
     
       27. The sealed lead-acid cell of  claim 17  wherein said internal plate restraint comprises a plastic insert resting on said positive plate strap when said cell is in an upright position and having an opening allowing electrical connection between said positive strap and positive terminal to be made. 
     
     
       28. A stationary uninterruptible power source system comprising an application system requiring an uninterruptible power source of particular electrical capacity, said application system being located in an area having a floor, a sealed lead-acid cell assembly having said particular electrical capacity and positioned adjacent said application system and electrically connected thereto, said cell assembly comprising cell support structure resting on the floor, a plurality of sealed cells providing the particular electrical capacity positioned on said cell support structure, each of said cells comprising a cell container sized to accommodate a cell element, a cell element positioned in said cell container and comprising a plurality of positive and negative plates and an absorbent separator positioned between adjacent plates, a cover sealed to said container and having an exterior and an interior surface, at least one positive terminal sealed to said cover and at least one negative terminal sealed to said cover each of said positive and negative plates having at least one lug, a positive strap electrically connecting the lugs of the respective positive plates together, a negative strap electrically connecting the lugs of said negative plates together, the positive strap being electrically connected to the positive terminal and the negative strap being connected to the negative terminal, an internal restraint contacting the interior surface of the cover and positioned between said positive plates and said cover, an external restraint connected to said cell support structure and in contact with the exterior surface of the cover and said external and internal restraints directing movement caused by positive grid growth in service in a direction away from the internal  interior surface of said cover, at least some of said cells being in a pancake orientation. 
     
     
       29. The stationary uninterruptible power source system of  claim 28  wherein all of said cells are in a pancake orientation. 
     
     
       30. The stationary uninterruptible power source system of  claim 29  wherein said application system is a telecommunications system. 
     
     
       31. The stationary uninterruptible power source system of  claim 30  wherein each of said cells has an electrical capacity of at least about 2,000 Ampere Hours. 
     
     
       32. A sealed lead- acid cell assembly for connection with additional cell assemblies to form a multicell battery for a stationary uninterruptible power source system, said assembly employing cells of a size susceptible to uneven separator saturation levels and electrolyte stratification, the sealed lead - acid cell assembly comprising    
         a cell support structure capable of supporting a plurality of sealed lead - acid cells,    
         at least one sealed lead - acid cell comprising    
       
         a cell container,  
       
       
         a cell element positioned in said cell container and comprising a plurality of positive and negative plates and an absorbent separator positioned between adjacent plates, the positive and negative plates and the separator being positioned in a pancake orientation, said separator saturation and said electrolyte stratification being minimized and electrical performance being enhanced, each of said positive and negative plates having at least one lug,  
       
       
         a cover sealed to said container and having an exterior and an interior surface,  
       
       
         at least one positive terminal sealed to said cover and at least one negative terminal sealed to said cover,  
       
       
         a positive strap electrically connecting the lugs of the respective positive plates together, the positive strap being electrically connected to the positive terminal, and  
       
       
         a negative strap electrically connecting the lugs of said negative plates together, the negative strap being electrically connected to the negative terminal.  
       
     
     
       33. The sealed lead- acid cell assembly of    claim 32    wherein the cover is plastic, the positive and negative terminals comprise an electrically conductive metal material having plastic surrounding said metal material, and said terminals having been heat sealed to provide a terminal - cover seal.    
     
     
       34. The sealed lead- acid cell assembly of    claim 33    wherein said heat - sealed cover has an open area about the terminal and a hot melt adhesive being contained in said open area.    
     
     
       35. The sealed lead- acid cell assembly of    claim 34    wherein said hot melt adhesive and at least the portion of said cover surrounding said hot melt adhesive each are colored the same.    
     
     
       36. The sealed lead- acid cell assembly of    claim 35    wherein in the positive terminal is colored red, the negative terminal is colored black, and said cover is gray.    
     
     
       37. The sealed lead- acid cell assembly of    claim 32    wherein said cell support structure is a tray.    
     
     
       38. The sealed lead- acid cell assembly of    claim 32    wherein said cell support structure is a rack.    
     
     
       39. The sealed lead- acid cell assembly of    claim 32    wherein said cell support structure is a cabinet.    
     
     
       40. The sealed lead- acid cell assembly of    claim 32    wherein the container has a bottom having an internal bottom surface, said negative plates have at least two spaced feet contacting said internal bottom surface, said negative plates being otherwise spaced from said bottom internal surface, and said positive plates being dimensioned such that said positive plates are spaced from the internal bottom surface of said container a distance sufficient to allow positive plate growth in service to occur.    
     
     
       41. The sealed lead- acid cell assembly of    claim 32    in which each of said positive and negative plates has at least two lugs and said cell has an electrical capacity of at least  2 , 000  Ampere Hours.    
     
     
       42. The sealed lead- acid cell assembly of    claim 41    wherein each positive and negative plate has at least two lugs and said cell has an electrical capacity of at least about  3 , 000  Ampere Hours.    
     
     
       43. The sealed lead- acid cell assembly of    claim 32    wherein said positive and negative plates have a height to width ratio of less than  2 : 1 .    
     
     
       44. The sealed lead- acid cell assembly of    claim 32    wherein said separator comprises at least one layer of a single piece of material wrapped about said positive and negative plates in a serpentine fashion.    
     
     
       45. The sealed lead- acid cell assembly of    claim 32    wherein said separator is positioned between and about said positive and negative plates in a double U - wrap configuration.    
     
     
       46. A sealed lead- acid cell assembly for connection with additional cell assemblies to form a multicell battery for a stationary uninterruptible power source system, said assembly employing cells of a size susceptible to uneven separator saturation levels and electrolyte stratification, the sealed lead - acid cell assembly comprising    
         a cell support structure capable of supporting a plurality of sealed lead - acid cells,    
         at least one sealed lead - acid cell comprising    
       
         a cell container,  
       
       
         a cell element positioned in said cell container and comprising a plurality of positive and negative plates and an absorbent separator positioned between adjacent plates, the positive and negative plates and the separator being positioned in a pancake orientation said separator saturation and said electrolyte stratification being minimized and electrical performance being enhanced, each of said positive and negative plates having at least one lug,  
       
       
         a cover sealed to said container and having an exterior and an interior surface,  
       
       
         at least one positive terminal sealed to said cover and at least one negative terminal sealed to said cover,  
       
       
         a positive strap electrically connecting the lugs of the respective positive plates together, the positive strap being electrically connected to the positive terminal,  
       
       
         a negative strap electrically connecting the lugs of said negative plates together, the negative strap being electrically connected to the negative terminal, and  
       
       
         an external restraint connected to said cell support structure and in contact with the exterior surface of the cover.  
       
     
     
       47. The sealed lead- acid cell assembly of    claim 46    wherein said external restraint comprises a metallic face plate positioned on the exterior surface of the cover and attached to said cell support structure.    
     
     
       48. A sealed lead- acid cell assembly for connection with additional cell assemblies to form a multicell battery for a stationary uninterruptible power source system, said assembly employing cells of a size susceptible to uneven separator saturation levels and electrolyte stratification, the sealed lead - acid cell assembly comprising    
         a cell support structure capable of supporting a plurality of sealed lead - acid cells,    
         at least one sealed lead - acid cell comprising    
       
         a cell container,  
       
       
         a cell element positioned in said cell container and comprising a plurality of positive and negative plates and an absorbent separator positioned between adjacent plates, the positive and negative plates and the separator being positioned in a pancake orientation said separator saturation and said electrolyte stratification being minimized and electrical performance being enhanced, each of said positive and negative plates having at least one lug,  
       
       
         a cover sealed to said container and having an exterior and an interior surface,  
       
       
         at least one positive terminal sealed to said cover and at least one negative terminal sealed to said cover,  
       
       
         a positive strap electrically connecting the lugs of the respective positive plates together, the positive strap being electrically connected to the positive terminal,  
       
       
         a negative strap electrically connecting the lugs of said negative plates together, the negative strap being electrically connected to the negative terminal, and  
       
       
         an internal restraint contacting the interior surface of the cover and positioned between said positive plates and said cover.  
       
     
     
       49. The sealed lead- acid cell assembly of    claim 48    wherein said internal restraint comprises a plastic insert resting on said positive plate strap when said cell in an upright position and having an opening allowing electrical connection between said positive strap and positive terminal to be made.    
     
     
       50. A stationary uninterruptible power source system for an application system requiring an uninterruptible power source of particular electrical capacity, said stationary uninterruptible power source system employing cells of a size susceptible to uneven separator saturation levels and electrolyte stratification, said stationary uninterruptible power source system being located in an area having a floor, said stationary uninterruptible power source system comprising 
         a cell support structure resting on the floor, said cell support structure being capable of supporting a plurality of sealed lead - acid cells, said sealed lead - acid cells being electrically connected to said application system,    
         at least one sealed lead - acid cell comprising    
       
         a cell container,  
       
       
         a cell element positioned in said cell container and comprising a plurality of positive and negative plates and an absorbent separator positioned between adjacent plates, the positive and negative plates and the separator being positioned in a pancake orientation, said separator saturation and said electrolyte stratification being minimized and electrical performance being enhanced, each of said positive and negative plates having at least one lug,  
       
       
         a cover sealed to said container and having an exterior and an interior surface,  
       
       
         at least one positive terminal sealed to said cover and at least one negative terminal sealed to said cover,  
       
       
         a positive strap electrically connecting the lugs of the respective positive plates together, the positive strap being electrically connected to the positive terminal, and  
       
       
         a negative strap electrically connecting the lugs of said negative plates together, the negative strap being electrically connected to the negative terminal.  
       
     
     
       51. The stationary uninterruptible power source system of  claim 50  wherein the cover is plastic, the positive and negative terminals comprise an electrically conductive metal material having plastic surrounding said metal material, and said terminals having been heat sealed to provide a terminal- cover seal.    
     
     
       52. The stationary uninterruptible power source system of  claim 51  wherein said heat- sealed cover has an open area about the terminal and a hot melt adhesive being contained in said open area.    
     
     
       53. The stationary uninterruptible power source system of  claim 52  wherein said hot melt adhesive and at least the portion of said cover surrounding said hot melt adhesive each are colored the same.  
     
     
       54. The stationary uninterruptible power source system of  claim 53  where in the positive terminal is colored red, the negative terminal is colored black, and said cover is gray.  
     
     
       55. The stationary uninterruptible power source system of  claim 50  wherein said cell support structure is a tray.  
     
     
       56. The stationary uninterruptible power source system of  claim 50  wherein said cell support structure is a rack.  
     
     
       57. The stationary uninterruptible power source system of  claim 50  wherein said cell support structure is a cabinet.  
     
     
       58. The stationary uninterruptible power source system of  claim 50  wherein the container has a bottom having an internal bottom surface, said negative plates have at least two spaced feet contacting said internal bottom surface, said negative plates being otherwise spaced from said bottom internal surface, and said positive plates being dimensioned such that said positive plates are spaced from the internal bottom surface of said container a distance sufficient to allow positive plate growth in service to occur.  
     
     
       59. The stationary uninterruptible power source system of  claim 50  in which each of said positive and negative plates has at least two lugs and said cell has an electrical capacity of at least  2 , 000  Ampere Hours.  
     
     
       60. The stationary uninterruptible power source system of  claim 59  wherein each positive and negative plate has at least two lugs and said cell has an electrical capacity of at least about  3 , 000  Ampere Hours.  
     
     
       61. The stationary uninterruptible power source system of  claim 50  wherein said positive and negative plates have a height to width ratio of less than  2 : 1 .  
     
     
       62. The stationary uninterruptible power source system of  claim 50  wherein said separator comprises at least one layer of a single piece of material wrapped about said positive and negative plates in a serpentine fashion.  
     
     
       63. The stationary uninterruptible power source system of  claim 50  wherein said separator is positioned between and about said positive and negative plates in a double U- wrap configuration.    
     
     
       64. A stationary uninterruptible power source system for an application system requiring an uninterruptible power source of particular electrical capacity, said stationary uninterruptible power source system employing cells of a size susceptible to uneven separator saturation levels and electrolyte stratification, said stationary uninterruptible power source system being located in an area having a floor, said stationary uninterruptible power source system comprising 
         a cell support structure resting on the floor, said cell support structure being capable of supporting a plurality of sealed lead - acid cells, said sealed lead - acid cells being electrically connected to said application system,    
         at least one sealed lead - acid cell comprising    
       
         a cell container,  
       
       
         a cell element positioned in said cell container and comprising a plurality of positive and negative plates and an absorbent separator positioned between adjacent plates, the positive and negative plates and the separator being positioned in a pancake orientation said separator saturation and said electrolyte stratification being minimized and electrical performance being enhanced, each of said positive and negative plates having at least one lug,  
       
       
         a cover sealed to said container and having an exterior and an interior surface,  
       
       
         at least one positive terminal sealed to said cover and at least one negative terminal sealed to said cover,  
       
       
         a positive strap electrically connecting the lugs of the respective positive plates together, the positive strap being electrically connected to the positive terminal,  
       
       
         a negative strap electrically connecting the lugs of said negative plates together, the negative strap being electrically connected to the negative terminal, and  
       
       
         an external restraint connected to said cell support structure and in contact with the exterior surface of the cover.  
       
     
     
       65. The stationary uninterruptible power source system of  claim 64  wherein said external restraint comprises a metallic face plate positioned on the exterior surface of the cover and attached to said cell support structure.  
     
     
       66. A stationary uninterruptible power source system for an application system requiring an uninterruptible power source of particular electrical capacity, said stationary uninterruptible power source system employing cells of a size susceptible to uneven separator saturation levels and electrolyte stratification, said stationary uninterruptible power source system being located in an area having a floor, said stationary uninterruptible power source system comprising 
         a cell support structure resting on the floor, said cell support structure being capable of supporting a plurality of sealed lead - acid cells, said sealed lead - acid cells being electrically connected to said application system,    
         at least one sealed lead - acid cell comprising    
       
         a cell container,  
       
       
         a cell element positioned in said cell container and comprising a plurality of positive and negative plates and an absorbent separator positioned between adjacent plates, the positive and negative plates and the separator being positioned in a pancake orientation said separator saturation and said electrolyte stratification being minimized and electrical performance being enhanced, each of said positive and negative plates having at least one lug,  
       
       
         a cover sealed to said container and having an exterior and an interior surface,  
       
       
         at least one positive terminal sealed to said cover and at least one negative terminal sealed to said cover,  
       
       
         a positive strap electrically connecting the lugs of the respective positive plates together, the positive strap being electrically connected to the positive terminal,  
       
       
         a negative strap electrically connecting the lugs of said negative plates together, the negative strap being electrically connected to the negative terminal, and  
       
       
         an internal restraint contacting the interior surface of the cover and positioned between said positive plates and said cover.  
       
     
     
       67. The stationary uninterruptible power source system of  claim 66  wherein said internal restraint comprises a plastic insert resting on said positive plate strap when said cell in an upright position and having an opening allowing electrical connection between said positive strap and positive terminal to be made.