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CHARGERS FOR BATTERIES WITH AUXILIARY CELLS

IP.com Disclosure Number: IPCOM000005763D
Original Publication Date: 1988-Oct-01
Included in the Prior Art Database: 2001-Nov-02
Document File: 2 page(s) / 94K

Publishing Venue

Motorola

Related People

Leon Jasinski: AUTHOR

Abstract

New type of high-energy density, rechargeable cells have highly variable voltage during discharging (as well as during charging) process. Auxiliary cells in addition to the basic cells are used in the batteries to solve this problem. Auxiliary cells are being connected in series with the basic cells whenever voltage on partially discharged basic cells drops below some predetermined level. Auxiliary cells are discharged unevenly and to a different charge level than the basic cells. These batteries cannot be charged with a conventional charger and require a special charger.

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MO7VROLA Technical Developments Volume 8 October 1988

CHARGERS FOR BATTERIES WITH AUXILIARY CELLS

by Leon Jasinski

   New type of high-energy density, rechargeable cells have highly variable voltage during discharging (as well as during charging) process. Auxiliary cells in addition to the basic cells are used in the batteries to solve this problem. Auxiliary cells are being connected in series with the basic cells whenever voltage on partially discharged basic cells drops below some predetermined level. Auxiliary cells are discharged unevenly and to a different charge level than the basic cells. These batteries cannot be charged with a conventional charger and require a special charger.

   A new type of charger was designed which separately charges and monitors two auxiliary cells and a group of basic cells. Block diagram with functional blocks is presented on figure 1. An example of the functional block realization is shown in figure 2.

   The charger operates as follows: Power supply 10 supplies DC or rectified AC voltage to the constant cur- rent regulator 20. The regulator assures that the batteries are charged with constant current. Switch 21 is used to disconnect voltage from terminal 1 whenever charging process is completed or the battery is disconnected from the charger. Diode DI is used to prevent battery discharge after the charging process is completed. Full Charge Detectors 30,31 and 32 determine when basic cells Bq, auxiliary cell B2 and 83 become fully charged. Voltage level is used to detect the fully charged state of the cells. The charger is designed to complete charging auxiliary cell 83 first, cell 62 second and basic cells Bq as the last. This charge completion order is used, since in normal battery operation most of the cha...