SE9901579A0 - Method and apparatus for reconditioning and recharging of rechargeable batteries - Google Patents

Description

PROCEDURE AND DEVICE FOR RECOMMENDATION AND CHARGING OF RECHARGEABLE BATTERIES The present invention relates to a method and apparatus for reconditioning and charging rechargeable batteries, the apparatus comprising a charging unit for current charging and constant voltage charging of a bat. It is previously possible to recondition batteries for this purpose. Extend their service life, see for example Swedish patent application 9301756-4. This patent application describes a medium charge and reconditioning of sulfated lead batteries. Pulse rate is used here, whereby the pulse voltage is sufficiently high and to achieve so-called gassing at the positive and negative poles of the battery. The direct voltage is applied in the form of pulses of a length of 0.5 to 10 s, the device delivering sbtim to the bacterium, which pulses are also separated by strOmlOsa intervals of the size of 0.5 to 10 s.

It is odcsa edge aft tilifOra its so-called Canpulser at conventional battery- charge. However, these canpulses are not suitable for reconditioning batteries, but only for the purpose of counter-crystal formation in batteries, which are otherwise well seated.

The object of the present invention is to provide a new technique for re- conditioning and charging of rechargeable batteries, as at effelctivam An the prior art and majliggOr reconditioning or * charging The life of batteries, which Sr in such a bad ski (all they previously could not be reconditioned. By reconditioning feirlangs the battery's Ilvsliingd. Required from 4 - 5 years to a basically spiritual life.

This jam is obtained by the method according to claim 1 and a device according to claim 7.

In the present invention, the reconditioning and charging are thus carried out according to a predetermined current saturation process, which is adapted to the fill condition of the battery in question. This adaptation to the condition of the battery meant determined% noon is determined by one or more periods of current pulse charging alternating with one or more periods of constant voltage charging. In this case, the power to the battery is fed continuously. Mr Mt controls the power supply in accordance with the said Wimp. With the present invention, reconditioning of the lives of hopelessly used batteries to a level of 96% of the new battery is possible. The technology according to 2 the invention is also not only usable for reconditioning and charging of lead-acid accumulators, but the life of, for example, low-cell battery batteries. Due to the continuous depletion of the current to the battery, the tive has proved to be particularly dangerous, since the electric current draws a direct determinant of the supplied charge. size Furthermore, in the case of batteries that are in very poor slddc, the voltage at con- DC voltage charging is limited to aft barja with for aft not risk all the battery explodes, warpi the voltage then gradually Okas as the battery is IMPROVED. Due to the continuous current generation, Wan current regulation pit is temporarily improved.

According to an advantageous embodiment of the process according to the invention finks the battery during the pulse pulse supply period current pulses with a substantially triangular shape. Through all the triangular shapes used, for a given pulse energy, a higher peak value An is obtained at a rectangular pulse, which turns out to increase the efficiency in decomposing the crystallization of the electrolyte.

According to another far-reaching embodiment of the method according to the invention, a supply current pulses with a length of less than 0.45 s. By using such short pulses, the energy supply and thus the swelling are reduced.

According to Annu, a far-reaching embodiment of the method according to the invention, the battery is supplied with current pulses at intervals during the current pulse supply periods. between the pulses of 1—10 s, dangerously 38. This reduces the risk of unauthorized heating of the electrolyte, as the temperature drops below these intervals. For a good batted kin the gap is made shorter An far eft dAligt batted. During these intervals, the feeding net also recovers.

According to Annu, another advantageous embodiment of the present invention The temperature of the battery is monitored continuously and if the temperature exceeds a maximum confidence awe grins, the charge is interrupted this temperature has dropped by a far-fixed amount, after which the charge is resumed with lower current. In the best case, this Batt avoids the mtudmaft toAtna stnamgransen Anyo Overskrids. Under all circumstances, this time again occurs with break In the charge as follows.

According to a further hazardous form of the process according to the invention, the number of periods of current pulse charge and constant voltage charge, period lengths, current amplitudes, pulse lengths and pulse frequencies, respectively, vary and are determined depending on 3 current battery adapted reconditioning and charging path. By simply varying the parameters period number, period lengths and current amplitudes, etc., the reconditioning and charging process can be optimized based on the condition of the current battery. 'War reconditioning cob charge is thus diagnosed the condition of the battery, usually by supplying the acid weight 0th / or the batted voltage, warp optimal reconditioning and charging path is determined. The significance of pulse length and pulse frequency has been mentioned above. However, if the battery is in very poor condition, the reconditioning must start with a current pulse charge. to access the battery before constant voltage charging can follow batteries it can be! MOM to start with a period of constant voltage charging, fait of a period of current pulse charging, etc. In general, current pulse charging involved reconditioning the battery and constant voltage charging gives the batted the essential charge. A subsequent incremental current discharge period can thus comprise only a strong current during a carefully controlled period of time. prevent the battery from becoming dangerous. The effect of avilenna strong initial pulse is avicrystallization of the lead atoms. If necessary, tiara such inhaling, strong tension pulses may be required. In step with the avicrystallization, the internal resistance of the battery decreases and the reconditioning and charging can & ergs% in other steps.

According to an advantageous embodiment of the device according to the invention, the tension sensor comprises at least one Hall element arranged in a ring-shaped ferric resistor arranged around one of the charging cables to determine the magnetic fiode state generated by the charging current in the ferrite cam and thus the size of the charging current. On delta salt you get a things, reliable and robust current sensor, as with Ojda temperatures, which can occur in connection with reconditioning and charging of batteries.

In order that the present invention will now be explained by way of example, an embodiment of the advertisement according to the invention will be explained in more detail with reference to the accompanying drawing, in which an embodiment will be illustrated in biomedical form.

The embodiment of the device according to the invention shown in the drawing one comprises a charging unit 2, which is operable in a current pulse charging mode and a constant voltage mode. Mean types of charging units are previously known and will not be described in deter !, see for example the above-mentioned Swedish patent application no. 9301756-4. 4 The charging unit 2 is connected via connection cables 4,6 to the poles 10, 12 of the batted 8 to be reconditioned 0th charged. A current sensor 14 is provided for continuously sensing the current directed to the battery 8 and emitting corresponding control signals to a control unit 16, which is arranged for controlling the charge. The supply voltage of the charging unit 2 is adjustable in the range 2 - 120 V. In the constant voltage mode, the battery 8 is normally supplied with 2.4 V per battery cell in the case of lead-acid accumulators. If one or tiers cotter in a batted Ar In a particularly poor condition, these cells can be given separate reconditioning treatment in the form of extra periods or long-term periods of voltage charging.

The charging unit 2 comprises current limiting means 20, suitably in form of current limiting resistor, father connection much needed. Namely, if the battery 8 is highly sulphated, the internal resistance is Ifigt. The battery 8 may be on the verge of short-circuiting, which is why the charging current is very slow in the first stage, which in any case can lead to the battery * bouncing. Far aft eliminate donna risk in- the current limiting means 20 are connected, so that the starting current is limited to e.g. 100 A. After the 8 condltion of the Mir battery is improved, the current can be raised, e.g. to 200 A, by successive disconnection of the current limiting means. With the current limiting device 20, the charging current can be regulated in the range 1 - 500A and the current limiting means 20 The connection and disconnection can be controlled from the control unit 16 in depending on, .with the tension sensor 14 avkand, tension strength.

The current sensor 14 Includes, around one of the cables 4,6, the standard cable to the battery's 8 negative pole, arranged, annular ferrite cam. In the recess in the ferrite cam or at least arranged after the Hall element, it is provided to deliver the control signal to the following control unit 16, representing the current in the cable 6 by sensing it, by the strain aistrade, the magnetic flOd state in the ferrite chamber. Lamply, two Hallelement are arranged in two, in different stalls the recesses of the king's ferriticamans are arranged, which Hallelement are adapted for different tight feeding areas, e.g. Hall element 1 for 0 - 100 A and Hall element 2 for 100— 500 A. Dot has now been shown to be black or to thank the entire current tight area with a single element.

The tension sensor 14 is suitably arranged to feed the charging tension with at regular intervals, e.g. every other selcund, and the current sensor 14 is arranged to feed the peak value of the charging current.

The charging unit 2 Ar arranged in the current pulse charging node supply the battery with 8 current pulses with a substantially triangular shape. Father certain pulse energy Ms at higher peak values than square pulses are used, which has been shown to give more efficient partial crystallization of the electrolyte.

The length of the base of the triangular pulses is in the omniclet 0.05 - 0.45 s, i.e. short charging pulses are used, which here reduces the beneficial effect of heating the battery. The current pulses are supplied to the battery at intervals of 0.5 s to 10 s, which also helps to avoid harmful and high heating of the battery. most intervals the median pulses are installed to a longer value. During these intervals, the pulses return to the supply line, indicated at 18 in the drawing. In the device according to the invention, the number of periods with current pulse charge and constant voltage charge, respectively, can be installed. Furthermore, such parameters as period lengths, current amplitudes, pulse lengths and pulse frequencies are variable and can be determined in% Nag depending on the condition of the boat to be conditioned and charged. After the initial state of the battery has been determined, the appropriate, adapted Arden on the said parameters for the reconditioning and charging process are thus set. After the reconditioning and charging cycles, the current comprises pulse pulse charging periods with constant voltage periods of 0-48 hours each, and the entire cycle can be Lox. ornfatts ten such cycles, i.e. maximum 48011 The alternation of current pulse charging periods and constant voltage periods can of course be varied in a number of ways as needed. A normal cycle can typically be 8 hours, e.g. 6 h pulse Charging charge saint 2 h constant voltage charge. Ten such cycles would thus take 80 hours. In the invention, however, continuous feeds are made, which can result in reconditioning and charging. the process is modified before the patient process, e.g. for cycles of 4 hours of nuclear pulse charging plus 4 hours of constant voltage charging, or cycles of 8 hours of pulse charging plus 8 hours of constant voltage charging. For longer periods of constant voltage, the battery is measured in a relatively good ski (before entering the heating should be not allowed high. 'l supply of current pulses to a batted generated frequencies in the range from 0 to about 20 MHz. The lead sulphate crystals here have a natural frequency of 3.77 MHz, which is why energy is absorbed efficiently at this frequency, which leads to the crystals being broken down, in the case of sulfur molecules in the case of lead accumulation in the case of lead accumulators with sulfuric acid as electrolyte. 6 When The supply voltage In the current pulse charge mode Exceeds the so-called gas voltage, 2.66 V / cell, you get a circulation of the acid in a lead accumulator. A discharged accumulator has a more or less hock deposit on the bottom of the accumulator and through this circulation of the acid the deposit comes off Stirred and 'Vitas' from the bottom, which leads to an equal supply of lead and lead dioxide to the accumulator electrodes. Practical tests have shown that a & Man deposit with a thickness of 40 mm is reduced to about 5 mm thickness to% IA of this stirring effect.

It is of great importance that the temperature of the battery during charging is not Exceeds the maximum permitted Upper limit, typically in the range of 50 ° C, after the battery degrades quickly. For this purpose, temperature sensor 22 is used for continuous monitoring of the battery temperature. The temperature sensor 22 is connected to the control unit 16 and when the temperature exceeds the food limit permitted upper limit, e.g. 50 ° C, stir the charging unit 2 to drain the charge until the temperature decreased by e.g. 2 °, warp the charge is resumed. The current supply process is suitably so instalft, because the control unit 16 in such a case down-regulates the power control somewhat, which is interrupted by the current sensor 14. On this salt avoids but, in the best case, the upper temperature limit is exceeded again and charging is interrupted, or atnitinstone temperature limit nas Wangs.

The invention has been described above in a way that applies to lead accumulators. rer, but the technique according to the invention Sr Sven applicable to other types of accumulators. Salunda Sr den val! Limped For use on NVCD accumulators for electric car operation. If the technology according to the invention is used on such batteries from the very beginning, when the batteries are new, and if the batteries are charged with relatively short time intervals, the batteries of continuous Nines will in full ski (0th habit charging and reconditioning Iran is carried out in a relatively short time, in its MO few hours. The procedure and device according to the invention thus allows charging of batteries for electric car operation on heft acceptabeft short time as batteries sit all it in principle hale fiden bibehalls I nybafteriskick. Ef- As this type of battery has a solid electrolyte, the battery voltage can only be relied upon when diagnosing the condition of the battery before reconditioning and charging. 7

Claims (12)

PATENT REQUIREMENTS Procedure may recondition and charge a rechargeable batted, in which process reconditonation and charging is performed according to a predetermined current supply barrel with one or more periods of current pulse charging of the battery alternating with one or more periods of constant voltage charging, the current supplied to the battery continues. mats fOr aft control the tight feed to the track to aft follow the said predetermined fOrtopp. r •. 10 Method according to claim 1, characterized by aft during periods of bulk pulse charging, batteries are supplied with pulse pulses of essentially triangular shape. Method according to Claim 1 or 2, characterized in that tension pulses with a length of less than 0.45 s are produced during the current pulse charge. 4. A method according to any one of the preceding claims, which may, during the current pulse charge, supply the battery with current pulses at intervals between the pulses of 1 to 10 s, preferably 3 $. 5. Procedure according to any of the preceding patent claims, Icannetecknat av aft bafteriet's temperature Monitored continuously 0th if the temperature Exceeds a maximum eaten Ovre wens the charge is interrupted until the temperature has dropped by eft Predefined amount, after which the charge is resumed with; Ogre current. Procedure according to one of the preceding claims, characterized by the total number of periods of current pulse and constant voltage charging, period lengths, current amplitudes, pulse lengths and pulse frequencies for varlable and determined depending on the condition of the battery for determining the reconditioning and charging charge adapted to the current battery. 7. Device for reconditioning and charging rechargeable batteries, comprising a charging unit for current pulse or constant voltage charging of a battery, characterized by a current sensor being arranged to continuously reduce the current to the battery Miranda current and output a corresponding control signal to a control unit, , aft control the charging unit to aft alternate between periods of current pulse charging and periods of constant voltage charging according to one of the condition of the battery, predetermined current supply path. s Device according to claim 7, characterized in that the charging unit is arranged to emit substantially triangular pulses during current pulse charging. Device according to claim 7 or 8, characterized in that the charging unit is arranged to emit pulses with a length of less than 0.45 s during intervals of current pulse charging with intervals between the pulses of 1-10 s. Device according to any one of claims 7 - 9, characterized in that the current transducer comprises at least one Hal element arranged in an annular ferrite chamber arranged around one of the charging cables for all the magnetic flow state generated by the charging current in the ferrite chamber and thus the charging point current. Device according to any one of claims 7 - 10, characterized by the current transducer arranged at regular intervals. Device according to any one of claims 7 - 11, enclosed by the current sensor, is arranged when, in the case of current pulse charging, the peak values of the current pulses are measured. a •% a