Battery chargers for secondary cells, and or batteries
First Claim
1. A battery charging system comprising a large lead-acid storage battery having at least two terminals with a potential therebetween, at least one small sealed nickel-cadmium battery which charges to a voltage which is slightly less than said potential, the energy stored in said large battery greatly exceeding the maximum energy that can be stored in said small battery, means for connecting said small battery into a circuit powered by the potential between said two terminals whereby the charge levels in said two batteries seek an equilibrium, the maximum amount of energy stored in said small battery after said equilibrium of charge levels is reached being such that virtually all of the energy previously stored in said large battery remains after said small battery is fully charged, said connecting means includes a plurality of diodes connected to limit the potential of said large battery as applied to said small battery, said limit being a level of about 1.40 to 1.45 volts per small battery cell, means connected across at least one of said series of diodes for shunting said one of said series of diodes, said shunting means being operated or not operated depending upon whether said large battery is or is not being charged and means for operating said shunting means responsive to the current or voltage level in said series circuit.
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Accused Products
Abstract
A battery charger for a nickel-cadmium cell, or the like, uses a large battery, such as an acid-lead automobile battery. Electrodes depend from the fill caps and into the electrolyte to make a plurality of potential points. Each of the cells in the large battery includes two sets of plates, with the individual plates in each set being joined at one end by a common bus bar. A terminal extends from each of these bus bars through the case of the acid-lead battery, to provide another plurality of potential points. A small battery, such as at least one nickel-cadmium cell is coupled to selected ones of the potential points so that the potential across the selected potential points equalizes with the potential of the small battery.
16 Citations
12 Claims
- 1. A battery charging system comprising a large lead-acid storage battery having at least two terminals with a potential therebetween, at least one small sealed nickel-cadmium battery which charges to a voltage which is slightly less than said potential, the energy stored in said large battery greatly exceeding the maximum energy that can be stored in said small battery, means for connecting said small battery into a circuit powered by the potential between said two terminals whereby the charge levels in said two batteries seek an equilibrium, the maximum amount of energy stored in said small battery after said equilibrium of charge levels is reached being such that virtually all of the energy previously stored in said large battery remains after said small battery is fully charged, said connecting means includes a plurality of diodes connected to limit the potential of said large battery as applied to said small battery, said limit being a level of about 1.40 to 1.45 volts per small battery cell, means connected across at least one of said series of diodes for shunting said one of said series of diodes, said shunting means being operated or not operated depending upon whether said large battery is or is not being charged and means for operating said shunting means responsive to the current or voltage level in said series circuit.
Specification