Battery charging method

DETAILED DESCRIPTION An object of the invention is to dynamically determine the resistance of the battery charging circuit.
Another object of the invention is to determine dynamically while charging, the open circuit battery voltage.
Yet another object of the invention to measure the open circuit battery voltage while charging with a reduced number of charger components.
Still another object of the present invention is to determine the charging circuit resistance for detecting internal series battery resistance changes that signal the gassing point of the charging cycle.
The invention is a method for dynamically determining the charge related changes in battery internal resistance as required for proper charging control.
The present invention uses a conventional set of equations to calculate battery series internal resistance and open circuit battery voltage.
The invention dynamically determines the charging loop resistance during charging and determines the open circuit battery voltage calculated dynamically while the battery is being charged.
The method is preferably embodied in a battery charging circuit which includes the battery charger terminals and internal connections, the charging cable resistance, the battery terminal connections, the internal battery series resistance, and the charger current measurement shunt resistor.
The open circuit battery voltage is calculated directly from the determined charging circuit resistance, and the average charger voltage and average charging circuit current.
The invention dynamically determines the open circuit battery voltage without charge interruption nor with extra battery voltage sensing lead wires.
It has been discovered that measurement and comparison of charging circuit resistance during battery charge will enable gas point detection, and consequent correct termination of battery charge.
The invention is an effective method of determining changes in battery internal series resistance.
In the preferred form, a power transformer provides ripple current and voltage through controlled rectifiers to charging capacitor providing power to the battery under charge