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Expired Canadian patentCanada

Electrical storage cell life extender

CA 1319952 C · Owner: Bell Communications Research, Inc. · Inventors: O'Sullivan, Thomas Denis; Mistry, Keku Minoo

CIPO record

Overview

Drawings and full text

Its claims, description and drawings are in the Canadian Patents Database.

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Abstract From the Canadian patent

The useful life of an electrolytic battery cell commonly employed in a series string as a backup power source is significantly extended by maintaining the polarization of the positive plates of such a cell at a predetermined level relative to a reference electrode of similar composition in contact with the cell electrolyte. While the cell is being supplied with the usual float charging voltage, a controller circuit senses any variance of polarization below the desired level and meters a minute input current to the positive plates with a resulting increase in the polarization over a substantial time period. The slow biasing of the polarization effects a passivation of the surface of the …

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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.

Why it's free to use

  • Granted July 6, 1993. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended July 6, 2010.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledSeptember 1, 1989
GrantedJuly 6, 1993
Term endedJuly 6, 2010
Patent numberCA 1319952 C
Classification (IPC)H02J7/10 +2 more

Timeline

Timeline From CIPO dates

1990199319961999200220052008Application filedSep 1, 1989Patent grantedJuly 6, 1993Term endedJuly 6, 2010

Sources & verification

Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.