Method and apparatus for charging lead-acid-accumulators
First Claim
1. A method for charging lead-acid-accumulators, wherein the charging current above the charging voltage level at which gassing occurs decreases with increasing charging voltage according to a mainly linear characteristic, characterized in that the charging current and the charging voltage per accumulator-cell is controlled in such a way, that the linear characteristic (3,302) followed above the gassing voltage level crosses the gassing voltage level at about 0.5 I5, and has an inclination (a) between approximately 0.5 V/I5 and approximately 0.1 V/I5.
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Abstract
The charging apparatus for lead-acid-accumulators controls the charging current and the charging voltage above the gassing voltage level according to a linearly declining characteristic. The charging current and the charging voltage are converted to a current signal (50) and a voltage signal (60) which are normalized (70, 80) and combined (150) into an indicating signal (160) which is constant as long as the charging current and the charging voltage follow the linear characteristic. A regulating device (130, 140, 40) compares the indicating signal (160) to a reference signal (132) for correcting the charging current and the charging voltage. The current signal (50) and the voltage signal (60) are converted to the indicating signal (160) by means of a weighted summation. For performing the summation there is provided an operational amplifier circuit.
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9 Claims
- 1. A method for charging lead-acid-accumulators, wherein the charging current above the charging voltage level at which gassing occurs decreases with increasing charging voltage according to a mainly linear characteristic, characterized in that the charging current and the charging voltage per accumulator-cell is controlled in such a way, that the linear characteristic (3,302) followed above the gassing voltage level crosses the gassing voltage level at about 0.5 I5, and has an inclination (a) between approximately 0.5 V/I5 and approximately 0.1 V/I5.
- 3. Apparatus for charging lead-acid-accumulators, where the charging current above the charging voltage level at which gassing occurs decreases with increasing charging voltage according to a mainly linear characteristic, and which is provided with a controllable charging current source, a current sensor for providing a first signal in proportion with the charging current, a voltage sensor for providing a second signal in proportion with the charging voltage, and a control device coupled to the sensors and to the charging current source for controlling the charging process, characterized in that the control device is furnished with at least one converter device (70,80,150) for converting the first signal (50,55) and the second signal (60,65) to an indication signal (160) which is constant to the extent that the charging current and the charging voltage are following the linear characteristic (3,302), and with at least one regulating device (30,40,130) which is configured to provide, by comparing the indication signal (160) with a reference signal (132), a regulating signal for the charging current source (20) such that the charging current and the charging voltage at any time are corrected in accordance with the linear characteristic (3,302).
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