(19)
(11)EP 1 073 137 A3

(12)EUROPEAN PATENT APPLICATION

(88)Date of publication A3:
31.08.2005 Bulletin 2005/35

(43)Date of publication A2:
31.01.2001 Bulletin 2001/05

(21)Application number: 00113408.9

(22)Date of filing:  23.06.2000
(51)Int. Cl.7H01M 4/84, H01M 4/73
(84)Designated Contracting States:
AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE
Designated Extension States:
AL LT LV MK RO SI

(30)Priority: 30.07.1999 US 364639

(71)Applicant: WIRTZ MANUFACTURING COMPANY, INC.
Port Huron, MI 48062 (US)

(72)Inventor:
  • Wirtz, John O.
    Fort Gratiot, MI 48059 (US)

(74)Representative: Wehnert, Werner et al
Patentanwälte Hauck, Graalfs, Wehnert, Döring, Siemons, Schildberg Mozartstrasse 23
80336 München
80336 München (DE)

  


(54)Battery grids


(57) A battery positive grid is continuously cast of lead and thereafter reduced in cross sectional thickness and elongated to change the microstructure of the lead and provide enhanced corrosion resistance and other properties needed for positive grids. The as cast thickness of the positive grids is reduced by not more than 1/2 or 2 to 1, to produce a positive grid which improves the life of a battery in which it is used. A battery negative grid is continuously cast of lead and thereafter reduced in cross sectional thickness and elongated to increase the ultimate tensile strength needed for a lighter negative grid. The as cast thickness of the negative grids is reduced in the range of about 1.2:1 to 2:1 to produce the desired properties for negative grids after age hardening.