SU750617A1 - Unsealed storage battery charging method - Google Patents

Description

(54) METHOD FOR CHARGING NON-TIGHT BATTERY

one

This invention relates to the field of chemical current sources.

An electric unpressurized battery with an additional electrode is known, which in the process of charging can receive information about the completeness of its charge in the form of an electrical signal regardless of the method of supplying current and the conditions of charge 1.

The magnitude of the signal current, i.e., the current in the circuit, a positive electrode — an additional electrode — generally depends on a number of factors: battery design, charge current, electrolyte temperature, etc., which leads to certain difficulties development of an automatic battery shutdown device.

Thus, despite the fact that in a non-hermetic battery with an additional electrode and it is important to continuously receive information about the degree of its charge during charging, there are difficulties in recording this information, which consists in a significant change in the magnitude of the signal current depending on battery design and operating conditions.

Also known is the charge of a battery with an additional electrode absorbing oxygen and disconnecting the battery from the charging circuit when the voltage between the additional and negative electrodes reaches a certain value 2.

Methods are known for charging a battery using an additional electrode 10 and controlling the charging process by comparing the voltage of an additional electrode with a reference voltage 3.

A battery voltage charging device in the constant voltage mode is known, according to which I control the charging end process.

15 is the largest first derivative of the charge current (in time -g-J) 4.

Claims (5)

There are also systems for fast charging, for example, for hermetic compact nickel-cadmium batteries, in which the signal parameters use the rate of change of battery voltage or the rate of change of current in the circuit of the additional electrode that adsorbs oxygen 5. However, all known methods of controlling the charging process does not allow one to determine with sufficient accuracy the end of the charge, which ultimately results in - by recharging or undercharging the batteries. The aim of the invention is to improve the electrical and operational characteristics of the battery. To this end, when charging a non-hermetic battery with an additional electrode, applying a charge current to control the magnitude of the first derivative of the signal current over the time flowing in the circuit between the positive and additional electrodes, and disconnecting the charge current when the specified control parameter of the previously set value is reached this is a shutdown at the value of the first derivative of the signal current, equal in time to zero, and the previous negative value of the second derivative of the signal current at the time eni The figure shows the dependences of the currents in the positive electrode – additional electrode circuit (i.e., signal currents) as a function of the capacitance of the battery for two different charging currents. It is known that at the beginning of the charge of the battery, regardless of the method of supplying the current and its magnitude, the current utilization rate at the positive electrode is almost 100% and, accordingly, the proportion of current consumed for the release of oxygen is zero. Consequently, the magnitude of the signal current at the beginning of the charge must be equal to a constant value due to the solubility of oxygen in the electrolyte. Indeed, at the beginning of the charge, both on curve 1 and on curve 2 there is a straight line segment parallel to the abscissa axis, which cuts off a small amount on the ordinate. The value of the first derivative of the current over time in this area is zero, however, since the second derivative did not pass through a negative value (in the Horizontal section, it was also equal to zero), the premature switching off of the battery from the charging circuit does not occur. As the battery is charged, the signal current changes from a certain minimum value to a certain maximum value, after which it remains constant (the second horizontal section on curves 1 and 2). The magnitude of the maximum signal current, which corresponds to the battery’s full charge, for a given battery design depends on the magnitude of the charge current and the electrolyte temperature at the end of the charge, but the nature of the change in the first and second derivatives of the signal current over time remains the same: first increases from zero to some maximum value, then decreases again to zero, the second derivative at the point of maximum value of the first derivative changes its sign to ny. The curve illustrates the change in the signal current in the function imparted to the charge of an alkaline nickel-iron battery with a current of 75 A, the nominal capacity of the battery is 250 Ah, the electrolyte temperature at the end of the charge was 40 ° C. Curve 2 illustrates the change in the signal current of the same battery when charged with a current of 10 A, and the temperature of the electrolyte at the end of the charge was 20 ° C. As follows from the drawing, despite the fact that the absolute value of signal currents at the end of charge is almost 3 times, the points on curves 1 and 2, in which the first derivative becomes equal to O, and the second has already had a negative value, i.e. The points corresponding to the achievement of the full charge of the battery are answered by almost the same value of the charge capacity on the abscissa axis. Thus, the proposed charging method allows the unsealed battery to be disconnected at the moment of its full charge VJ of the charging circuit, regardless of the structural elements or operating conditions. Invention Method for charging an unpressurized battery with an additional electrode by supplying a charge current the magnitude of the first derivative of the signal current with respect to the time flowing in the circuit between the positive and additional electrodes and the switching off of the charging current upon reaching the specified control pair meter previously set value, characterized in that, in order uluchscheni electrical and operational characteristics is performed during said disconnection signal value of the first derivative of current with respect to time zero and predschestvuyuschemu negative value of the second derivative of the signal current with respect to time. Sources of information taken into account in the examination 1. Forward number 2040172/07, cl. H 01 M 10/48, 1974. 2. US patent number 3522507, cl. 320-31, published. 1970. 3. The patent of England No. 1347500, cl. H 2 H, pub. 1971. 4. US patent number 3889172, cl. 320--39, published. 1975. 5.IEEE Trans. Jnd and Gen. Applic, 1968, No. 4, 5 (prototype). -ABOUT tj § I 8 (ush) osh p / chchiongpo