Method for charging a nickel-cadmium accumulator and simultaneously testing its condition
First Claim
1. A method for charging and simultaneously testing the condition of a nickel-cadmium accumulator using a pulsing DC charging current of rectangular pulse shape including periods of low current intensity and periods of high current intensity, with cyclically intervening measuring phases including discharging intervals of relatively short duration, wherein the accumulator voltage is measured at the beginning of each high current-intensity period and at a preselected interval after the beginning of the respective period, and the difference of the thus measured voltage values is used for controlling the charging process, the method comprising for each measuring phase the steps of:
- a. providing a charging current pulse to be a rectangular pulse with a nominal current intensity IN,b. before the end of the charging current pulse of the nominal current intensity IN, measuring the accumulator voltage (test O) and storing the measured accumulator voltage as a balancing voltage,c. charging thereafter the accumulator with a higher current intensity for a preselected period (T2) of about 1 to 2 seconds, the higher current intensity being higher than IC which is the capacity of the accumulator, the higher current intensity being higher than the nominal current intensity, the accumulator voltage being measured about 0.2 sec after the beginning and at the end of this period (T2) (tests A and B),d. subsequently interrupting the current to the accumulator for a preselected period (T3) of about 1 to 2 seconds, the accumulator voltage being measured about 0.2 sec. after the beginning and at the end of this period (T3) (tests C and D),e. putting the accumulator under load with a load current of the magnitude -IC for a preselected load period (T4) of about 1 to 2 seconds, the accumulator voltage being measured immediately before the beginning, about 0.2 seconds after the beginning, and at the end of the load period (T4) (tests E, F and G),f. subsequently interrupting again the accumulator current for a preselected period (T5) of about 1 to 2 seconds, the accumulator voltage being measured about 0.2 seconds after the beginning of this period (T5) (test H),g. resuming the charging operation with a subsequent charging current pulse,h. determining the respective internal resistances of the accumulator from the measured voltage values and the associated current intensities, andi. the internal resistances determined in one measuring phase are interrelated with one another, and the interior resistances determined in corresponding tests of successive measuring phases are interrelated with one another, to result in data relating to the condition, the use, the charging state, the temperature and the type of the accumulator.
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Abstract
A method for charging and simultaneously testing the condition of a nickel-cadmium accumulator wherein the charging cycle includes intervening measuring phases with discharging phases of relatively short duration. During the measuring phases, the internal resistance of the accumulator is measured under different charging and discharging conditions. The measured internal resistances are interrelated and additionally compared to internal resistances determined during successive measuring phases. The thus found relationships are used to derive therefrom a comprehensive spectrum of informations relating to various states of the accumulator, these informations being used for controlling the charging operation and permitting the state of usefulness of the accumulator to be assessed.
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Citations
27 Claims
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1. A method for charging and simultaneously testing the condition of a nickel-cadmium accumulator using a pulsing DC charging current of rectangular pulse shape including periods of low current intensity and periods of high current intensity, with cyclically intervening measuring phases including discharging intervals of relatively short duration, wherein the accumulator voltage is measured at the beginning of each high current-intensity period and at a preselected interval after the beginning of the respective period, and the difference of the thus measured voltage values is used for controlling the charging process, the method comprising for each measuring phase the steps of:
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a. providing a charging current pulse to be a rectangular pulse with a nominal current intensity IN, b. before the end of the charging current pulse of the nominal current intensity IN, measuring the accumulator voltage (test O) and storing the measured accumulator voltage as a balancing voltage, c. charging thereafter the accumulator with a higher current intensity for a preselected period (T2) of about 1 to 2 seconds, the higher current intensity being higher than IC which is the capacity of the accumulator, the higher current intensity being higher than the nominal current intensity, the accumulator voltage being measured about 0.2 sec after the beginning and at the end of this period (T2) (tests A and B), d. subsequently interrupting the current to the accumulator for a preselected period (T3) of about 1 to 2 seconds, the accumulator voltage being measured about 0.2 sec. after the beginning and at the end of this period (T3) (tests C and D), e. putting the accumulator under load with a load current of the magnitude -IC for a preselected load period (T4) of about 1 to 2 seconds, the accumulator voltage being measured immediately before the beginning, about 0.2 seconds after the beginning, and at the end of the load period (T4) (tests E, F and G), f. subsequently interrupting again the accumulator current for a preselected period (T5) of about 1 to 2 seconds, the accumulator voltage being measured about 0.2 seconds after the beginning of this period (T5) (test H), g. resuming the charging operation with a subsequent charging current pulse, h. determining the respective internal resistances of the accumulator from the measured voltage values and the associated current intensities, and i. the internal resistances determined in one measuring phase are interrelated with one another, and the interior resistances determined in corresponding tests of successive measuring phases are interrelated with one another, to result in data relating to the condition, the use, the charging state, the temperature and the type of the accumulator. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
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22. A method for charging and simultaneously testing a condition of an accumulator, comprising the steps of:
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(a) applying a charging current to an accumulator, the charging current including a charging pulse superimposed by a current pulse of higher current intensity than said charging pulse; (b) discontinuing the superimposition of the current pulse to enable the accumulator to reach a state of equilibrium with respect to the charging pulse; (c) charging the accumulator with a higher current which is higher in intensity than that of the charging pulse; (d) interrupting the charging with the higher current and thereby the charging current so that the accumulator enters into a no-current state; (e) charging the accumulator with a load current; (f) interrupting the charging with the load current so that the accumulator enters into a no-current state; (g) measuring accumulator voltage after about 0.2 seconds from a beginning of steps (c) to (f) and at an end of steps (c) to (e) and also before the beginning of step (c) and after the end of step (d), the measuring during each of the steps (c) to (f) constituting a measuring phase; (h) determining respective internal resistances of the accumulator from the measured accumulator voltage of step (g) and from associated current intensities; and (i) comparing interrelationships between the internal resistances for each measuring phase and in successive measuring phases so as to obtain results indicative of a condition, a use, a charging state, a temperature and a type of the accumulator. - View Dependent Claims (23, 24, 25, 26, 27)
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Specification