DE102005036157A1 - Method for charge control of nickel-cadmium and nickel-metal hydride batteries and universal power supply device with various power sources - Google Patents

Abstract

The invention describes a method for charging control for power supply devices with removable nickel-cadmium or nickel-metal hydride batteries with either constant or non-constant power sources and a universal, inexpensive power supply device with this method. In addition to the possibility of charging batteries internally, such devices also offer the possibility of charging or operating external small mobile devices, the internal batteries then serving as a buffer. In the case of the present invention, the methods known in principle — DELTAU shutdown, balancing and W charging are used in a modified form either selectively or in a special chronological sequence. This means that batteries with initially unknown capacity can also be used with inconsistent power sources such as B. Solar generators can be defined and fully charged with an exact charge status indicator. In addition, in the operating modes balancing and W-charging, it is also possible to discharge the internal batteries for operating external devices. In addition to control electronics (5), a power supply device (1) according to the invention contains an integrated solar generator (2), rechargeable batteries (4), an input (3) for external power sources and an output (6) for external consumers.

Description

The The invention relates to a charging control method for power supply devices with removable nickel-cadmium (NiCd) or nickel-metal hydride (NiMH) Batteries with either constant or non-constant current sources as well as a universal power supply device with this Method.

NiCd and especially NiMH batteries are characterized by a high energy density, a high number of charge cycles, a low internal resistance and flat discharge curves. In particular, these are battery systems available as round cells in the typical sizes AAA, AA, C and D, the used in many mobile consumer products for power become. Due to their rated voltage of approx. 1.2 V, they are also replaceable through or replace usual Alkaline manganese or zinc-carbon primary cells with 1.5 V nominal voltage. Due to these characteristics, NiCd / NiMH batteries are also suitable for mobile use Power Devices such as. Solar charger or crank generators interesting.

• a) Feste Bilanzierung: Konstantstrom mit fest eingestelltem Timer
• b) Variable Bilanzierung: Ladungszählung mit variablem Maximalwert
• c) Abtastung des Spannungsverlaufs: –ΔU-Verfahren mit Abschaltung bei Abnahme der Klemmenspannung um einen definierten Wert ΔU
• d) Abtastung des Temperaturverlaufs: Abschaltung bei Erreichen einer Maximaltemperatur T_max bzw. eines maximalen Temperaturanstiegs dT/dt
• e) Diverse Verfahren mit Abtastung anderer innerer Akkuparameter wie z.B. Impedanz, dynamische Parameter etc. (z.B. CCS-Ladeverfahren der Fa. BTI in Kooperation mit der TU Graz).

When charging NiCd / NiMH batteries, in contrast to lead- or lithium-based battery systems or RAM cells (rechargeable alkaline-manganese batteries) no conventional constant-voltage charge control can be used, since NiCd / NiMH batteries with increasing charge state by internal gassing processes and thus accompanying pressure and temperature increase limit the terminal voltage and even slightly lower after reaching full state. Previous chargers for NiCd / NiMH batteries therefore work in principle with the following methods:

• a) Fixed balancing: Constant current with permanently set timer
• b) Variable balancing: charge counting with variable maximum value
• c) Scanning of the voltage curve: -ΔU-method with switch-off when the terminal voltage decreases by a defined value ΔU
• d) sampling of the temperature profile: shutdown when a maximum temperature T _max or a maximum temperature rise dT / dt is reached
• e) Various methods with sampling of other internal battery parameters such as impedance, dynamic parameters etc. (eg CCS charging method of BTI in cooperation with Graz University of Technology).

To on the relatively complex process e) require all the above method either constant charging current sources (Method a, c, d) or a knowledge of the battery capacity used (method b). A mobile charger with a charging slot for NiCd / NiMH batteries of any capacity for operation with different, Even autarkic power sources with inconsistent charging current is thus on a use of for Consumer devices too complicated process e) limited.

Mobile, self-sufficient power supply facilities with removable NiCd and / or NiMH batteries are known in various designs and for a variety of applications. In addition to the ability to recharge the said batteries internally, these facilities also offer in particular the ability to load or operate external small mobile devices such as mobile phones or organizers, the internal batteries then serve as a buffer. Examples from the patent literature are the DE 199 28 809 A1 . DE 203 11 011 U1 . CA 2 409 465 A1 Examples of corresponding solar chargers available on the market can be found, for example, on the Internet websites www.solarserver.de or www.conrad.de. All these examples are more or less universal chargers, which, however, contain no or only insufficient means for internal charge limitation, in particular of NiCd / NiMH rechargeable batteries. In most of the aforementioned inventions devices for connection to constant current sources such as power supplies or 12V car batteries are integrated in addition to the self-sufficient, non-constant power sources. This makes it possible, in the presence of such power sources to achieve a relatively fast and safe charging, especially if, for example, in the case of a solar charger no sufficient solar radiation is available. In the current state of the art, however, none of the charging method described above is used for charging control in such charging devices, but - as well as the non-constant power sources - an unlimited overload of the inserted batteries accepted.

The Task for The present invention is therefore to provide a Process for the regulated charging of any NiCd / NiMH batteries by different, optionally constant or non-constant current sources without pre-setting the battery capacity, as well as a mobile power supply, which uses this principle and is constructed accordingly. The inventive solution for this The object is the main claim and claim 10 refer. advantageous Further developments of the charging method according to the invention and the Power supply device are the respective dependent claims and will be discussed below in connection with the invention explained in more detail.

Essential for the present invention is the cooperation of three im. In a fixed temporal or functional scheme Principle known charging method, but taken alone or in a simple juxtaposition can not meet the above-formulated task. This results in a novel, self-tuned total charging method that covers all real-world requirements and can be realized inexpensively with a conventional microcontroller circuit. The basis for this is a power supply device which can be operated in the mobile case with non-constant power sources (eg solar generator), in the stationary case, however, with constant current sources (eg mains adapter). Furthermore, this device must be able to cause a discharge of the inserted removable batteries when supplying external consumers (eg mobile phones).

• 1. Der eingelegte Akku ist nahezu entladen (Q = Q₀), was anhand einer definierten unteren Spannungsschwelle U₀ automatisch detektiert wird. Diese Schwelle liegt typischerweise im Bereich 1,15 und 1,25 V. Falls sich der Akku nicht bereits im entladenen Zustand befindet, kann vom Benutzer ein Entladevorgang mit einem Entladestrom -I_EL gestartet werden, in dem der Akku bis zur Schwelle U₀ definiert entladen wird. Wird die Ladeeinrichtung danach mit einer konstanten Stromversorgung mit einem definierten Mindest-Ladestrom I_const betrieben, der ebenfalls durch die Ladeeinrichtung detektiert wird, so wird automatisch oder auch durch den Benutzer der Betriebsmodus 1 gestartet. Dabei wird der Akku mit Hilfe des bekannten –ΔU-Ladeverfahrens bis zum Erreichen eines negativen Spannungsgradienten (–ΔU) der Klemmenspannung U_kl innerhalb einer Zeitspanne Δt mit konstantem Strom I_const geladen und danach die Ladung beendet. Die so in den Akku eingeladene Strommenge I_const·Δt = (Q₁ – Q₀)·L entspricht der realen Kapazität Q₁ – Q₀ = Q_max = C_real des Akkus mal einem Ladefaktor L, der die reziproke Effizienz des Ladungsprozesses beschreibt. Die „Kapazität" C von Akkus wird dabei üblicherweise in Ladungseinheiten (Q = I·t) angegeben. Nach der automatischen Beendigung der Ladung wird der Wert Q_max des Ladungszählers intern gespeichert, damit gilt der Akku als kalibriert. Der Wert I_const kann im Bereich 0,3 bis 2 der zu erwartenden Akkukapazität in Ampère-Einheiten, also z.B. bei 2 Ah-Akkus 0,6 bis 4A, liegen.
• 2. Der in der Ladeeinrichtung befindliche Akku wurde im Betriebsmodus 1 vermessen (kalibriert). Nach diesem Vorgang geht die Ladeeinrichtung selbsttätig in den bilanzierenden Betriebsmodus 2 über, da nun die Akkukapazität C = Q_max und auch der aktuelle Ladungszustand bekannt und gespeichert ist. Erfolgt nun eine Entladung in ein angeschlossenes Kleingerät, so wird der Ladungszähler vom aktuellen Wert herabgezählt, bei Nachladung mit konstanten oder unkonstanten Stromquellen wird er heraufgezählt; die Stromkonstanz spielt für den gemäß Q(t) = Q₀ + ∫I(t)/L(t)dt ermittelten Ladungszustand keine Rolle. In diesem Zustand ist bei hinreichender Kenntnis des Ladefaktors L(t) auch eine genaue Ladezustandsanzeige möglich. Dieser Zustand wird erst wieder verlassen und damit der Ladungszähler und der gespeicherte Kapazitätswert zurückgesetzt, wenn der Akku entnommen wird, da die Ladeeinrichtung nicht „merkt", ob danach wieder derselbe Akku mit gleichem Ladungszustand eingelegt wird.
• 3. Der Akku weist nach dem Einlegen ins Akkufach weder eine Klemmenspannung unterhalb der Schwelle U₀ auf, noch wird eine Entladung vom Benutzer gestartet. In diesem Falle wird automatisch oder auch durch den Benutzer der Betriebsmodus 3 aktiviert, der ebenfalls wie Modus 2 mit konstanten oder unkonstanten Stromquellen betrieben werden kann. Es handelt sich um eine Abwandlung des für Blei-Akkus früher gelegentlich angewandten Verfahrens der „W-Ladung". Dabei wird während der Ladung der Ladestrom etwa umgekehrt proportional zur steigenden Akku-Klemmenspannung heruntergeregelt, wodurch in etwa ein konstantes Leistungsprodukt W = U·I entsteht. Dieses Verfahren enthält gegenüber einem bilanzierenden Verfahren wie in Modus 2 einerseits den Nachteil einer Strombegrenzung, insbesondere bei steigendem Ladungszustand des Akkus (entsprechend I = W/U), und andererseits den Nachteil einer relativ ungenauen Ladungszustandsanzeige, die hier nur an der Klemmenspannung des Akkus orientiert werden kann. Dennoch ist dieses Verfahren eine bessere, vor allem sicherere Alternative als die bei den beschriebenen Ladegeräten bislang üblichen ungeregelten Verfahren.

The following cases are possible:

• 1. The inserted battery is almost discharged (Q = Q ₀ ), which is automatically detected on the basis of a defined lower voltage threshold U ₀ . This threshold is typically in the range 1.15 and 1.25 V. If the battery is not already in the discharged state, the user can start a discharge process with a discharge current -I _EL , in which the battery is defined up to the threshold U ₀ unloaded. If the charging device is then operated with a constant current supply with a defined minimum charging current I _const , which is likewise detected by the charging device, the operating mode 1 is started automatically or even by the user. In this case, the battery with the aid of the known -ΔU charging method until a negative voltage gradient (-ΔU) of the terminal voltage U _{kl is} charged within a period of time .DELTA.t with constant current I _const and then terminates the charge. The amount of current I _const * Δt = (Q ₁ -Q ₀ ) * L thus charged into the battery corresponds to the real capacity Q ₁ -Q ₀ = Q _max = C _{real of} the battery times a charging factor L, which describes the reciprocal efficiency of the charging process , The "capacitance" C of the batteries is thereby usually in units of charge (Q = I · t) indicated. After the automatic completion of the charge, the value Q _max of the load counter is stored internally to the battery, the value I is considered to be calibrated. _Const may be in the Range 0.3 to 2 of the expected battery capacity in ampere units, so for example in 2 Ah batteries 0.6 to 4A, are.
• 2. The battery in the charger was measured (calibrated) in operating mode 1. After this process, the charging device automatically goes into the balancing operating mode 2, since now the battery capacity C = Q _max and also the current state of charge is known and stored. If a discharge then takes place in a connected small appliance, then the charge counter is counted down from the current value; if it is charged with constant or non-constant current sources, it is counted up; the current constancy plays no role for the charge state determined according to Q (t) = Q ₀ + ∫I (t) / L (t) dt. In this state, with sufficient knowledge of the charge factor L (t) and a precise charge status display is possible. This state is only left again and thus the charge counter and the stored capacity value reset when the battery is removed because the charging device does not "notice" whether afterwards the same battery with the same charge state is inserted.
• 3. The battery has after inserting into the battery compartment neither a terminal voltage below the threshold U ₀ , nor is a discharge started by the user. In this case, automatically or by the user of the operating mode 3 is activated, which can also be operated as Mode 2 with constant or non-constant power sources. This is a modification of the "W-charge" method previously used occasionally for lead-acid batteries, during which the charging current is regulated down in inverse proportion to the increasing battery terminal voltage, thus producing a constant power product W = U · I This method contains, on the one hand, the disadvantage of limiting the current compared to a balancing method as in mode 2, in particular when the state of charge of the battery is increasing (corresponding to I = W / V), and on the other hand the disadvantage of a relatively inaccurate charge state indication, which here only occurs at the terminal voltage of the battery Nevertheless, this method is a better, above all, safer alternative than the unregulated methods hitherto used in the described chargers.

• – Im Betriebsmodus 2 erfolgt ein Zurücksetzen des Ladungszählers auf den Wett Q₀, sobald durch einen Entladevorgang oder auch durch Selbstentladung die definierte untere Spannungsschwelle U₀ erreicht wird. Dadurch wird ein „Weglaufen" des Ladungszählers vom tatsächlichen Ladungszustand, z.B. durch einen abweichenden Ladefaktor L, verhindert.
• – Im Betriebsmodus 3 ist im Gegensatz zu den bisher üblichen primitiven Methoden der oben beschriebenen W-Laderegelung, die z.B. einen durch den Innenwiderstand eines Netztrafos bei steigender Sekundärspannung sinkenden Ladestrom ausnutzen, eine exakt definierte Abnahme des Ladestroms I_L von einem Maximalwert I_L,max bei Erreichen einer ersten Klemmenspannungsschwelle U_kl1 bis zu einem Minimalwert I_L,min bei Erreichen einer zweiten Klemmenspannungsschwelle U_kl2 vorgesehen.
• – Noch genauer wird dieses Verfahren durch die Berechnung eines sogenannten „Normwertes" der Akku-Klemmenspannung U_kl,norm, der durch das Einbeziehen aller Innenwiderstände R_i(T) im Gesamtsystem inklusive Akku gemäß U_kl,norm = U_kl,mess – R_i(T)·I_L unabhängig von dem aktuellen Lade- oder Entladestrom I_L ist. Mit Hilfe dieser auch in Abhängigkeit der Temperatur T korrigierbaren Klemmenspannung ist zudem eine exaktere Korrelation zwischen Klemmenspannung und Akkuladezustand möglich. Die Größe U_kl,norm entspricht im Idealfall genau der Ruhespannung bzw. offenen Klemmenspannung U_oc des Akkus. Anstatt der oben beschriebenen Normspannung U_kl,norm kann auch die nach Abschalten aller Ströme in den oder aus dem Akku gemessene Spannung U_oc für den Betriebsmodus 3 herangezogen werden. Nachteilig dabei sind jedoch die notwendigen Abschaltvorgänge des Stroms in den bzw. aus dem Akku, die bei einem eventuellen Entladebetrieb in ein angeschlossenes Endgerät stören. Somit eignet sich die stromlose Messmethode in erster Linie für reine Ladegeräte ohne zusätzliche Stromversorgungsfunktion für externe Geräte.
• – Weiterhin wird in Betriebsmodus 3 ab dem Zeitpunkt des Einlegens eines Akkus unabhängig von dessen Ladungszustand der interne Ladungszähler mit Q = Q₀ gestartet und bei Erreichen eines intern festgelegten Grenzwertes Q_lim gestoppt. Danach wird der Ladestrom auf einen niedrigen Erhaltungsladestromwert I_tr heruntergeregelt. Der Wert Q_lim sollte dabei über dem maximal zu erwartenden Kapazitätswert aller möglichen zu verwendenden Akkus liegen, damit ein Akku auf jeden Fall vollgeladen wird. Damit besitzt dieser Modus gegenüber den bisher bekannten „W-Ladeverfahren" erhebliche Vorteile, da keine unbegrenzte Überladung mehr möglich ist.
• – In den beiden Betriebsmodi 1 und 2 wird ebenfalls der Ladestrom auf einen niedrigen Erhaltungsladestromwert I_tr im Bereich ca. 0,01 bis 0,05·Q_max/h heruntergeregelt, sobald der Wert Q_max erreicht ist. In diesem Erhaltungslademodus wird der Ladungszähler nicht weiter hochgezählt, der Akku kann in diesem Zustand für unbegrenzte Zeit (abgesehen von seiner kalendarischen Lebensdauer) im Voll-Zustand gehalten werden. Idealerweise wird der Erhaltungsladestrom aus kurzen Strompulsen in Höhe des typischen Ladestroms gebildet, um die Ladeeffizienz zu steigern.
• – In allen drei beschriebenen Modi kann eine obere Spannungsschwelle der Klemmenspannung U_kl,max implementiert werden, die der maximalen Ladespannung von aufladbaren Alkali-Mangan Akkus (RAM) entspricht und typischerweise bei 1,65 bis 1,7 V liegt. Ab Erreichen dieser Schwelle ist dann keine weitere Erhöhung mehr möglich und der Ladestrom wird durch den Akku selbsttätig zurückgeregelt. Da diese Schwelle über der typischen Ladespannung von NiMH oder NiCd Akkus liegt, ist bei diesen nicht mit einer Begrenzung zu rechnen. Auch ist durch diese Maßnahme die Verwendung von Alkali-Mangan Primärzellen in einem Ladegerät als Notreserve z.B. zur Versorgung von extern angeschlossenen Kleingeräten möglich. Ein versehentliches Laden dieser Zellen kann damit nicht zu einem Überladen bzw. Auslaufen von Elektrolyt führen.

The user will thus, if possible, make use of the combination of operating modes 1 and 2 in order to use the great advantages of the balancing method 2 as a buffer, especially during frequent charging and discharging to supply external small appliances with the internal batteries, and he has otherwise the method 3 is a reasonably good alternative. The advantages of this coordinated combination are further enhanced by the following developments:

• - In operating mode 2, a reset of the charge counter takes place on the betting Q ₀ as soon as the defined lower voltage threshold U _{0 is} reached by a discharge process or by self-discharge. This prevents "running away" of the charge counter from the actual charge state, for example due to a different charge factor L.
• In operating mode 3, in contrast to the previously used primitive methods of the W charging control described above, the one example exploit decreasing charge current through the internal resistance of a network transformer with increasing secondary voltage, a precisely defined decrease of the charging current I _L from a maximum value I _{L, max} when reaching a first terminal voltage _threshold U _kl1 to a minimum value I _{L, min} when reaching a second terminal voltage _threshold U _kl2 ,
• - This process is even more accurate by calculating a so-called "standard value" of the battery terminal voltage U _{kl, norm} , by the inclusion of all internal resistance R _i (T) in the overall system including battery according to U _{kl, norm} = U _{kl, mess} - R _i (t) · I _L is independently of the current charging or discharging current I _L. Using this correctable also a function of the temperature T terminal voltage also a more exact correlation between the terminal voltage and battery state of charge is possible. the size of U _{kl, norm} corresponds in the ideal case exactly the open circuit voltage and the open terminal voltage V _oc of the battery. Instead of the standard voltage above described U _{kl, norm} may also be measured after switching off of all flows in or out of the battery voltage V _oc are used for the operation mode 3. disadvantage of this, however, the necessary shutdowns of the power in and out of the battery, which interfere with a possible unloading operation in a connected terminal Som The currentless measuring method is primarily suitable for use with pure chargers without additional power supply function for external devices.
• - Furthermore, in the operating mode 3 from the time of insertion of a battery regardless of its charge state of the internal charge counter with Q = Q _{0 is} started and stopped when reaching an internally set limit Q _lim . Thereafter, the charging current is reduced to a low trickle charging current value I _tr . The value Q _lim should be above the maximum expected capacity value of all possible batteries to use, so that a battery is fully charged in any case. Thus, this mode has over the previously known "W-charging" significant advantages, since no more unlimited overload is possible.
• - In the two modes of operation 1 and 2, the charging current is also down to a low trickle charge current value I _tr in the range of about 0.01 to 0.05 · Q _max / h, as soon as the value Q _{max is} reached. In this trickle charge mode, the charge counter stops counting, and the battery can be kept full for an indefinite period of time (except for its calendar life). Ideally, the trickle charge current is formed from short current pulses equal to the typical charging current to increase charging efficiency.
• - In all three modes described, an upper voltage threshold of the terminal voltage U _{kl, max can be} implemented, which corresponds to the maximum charging voltage of rechargeable alkaline manganese batteries (RAM) and is typically 1.65 to 1.7V. From reaching this threshold then no further increase is possible and the charging current is automatically controlled back by the battery. Since this threshold is higher than the typical charging voltage of NiMH or NiCd batteries, there is no limit to these. Also, by this measure, the use of alkaline manganese primary cells in a charger as an emergency reserve eg for the supply of externally connected small appliances possible. Accidental charging of these cells can not lead to overcharging or leakage of electrolyte.

It Now a universal power supply device is described, a concrete implementation of the above-explained method with suitable Represents components. These are at least one control electronics with the charging methods described above, one input for constant and non-constant power sources, a battery compartment for removable batteries and a Connection for external consumers. With the components mentioned can be the to accomplish the task resulting from the prior art, both Internally inserted NiCd or NiMH batteries of any capacity with constant or even uncontrolled power sources regulated charge as well Connected external small mobile devices such. Mobile phones or Organizer to charge or operate, with the internal batteries then serve as a buffer. The control electronics can typically be realized by means of a freely programmable microcontroller, the over A / D and D / A converter communicates with the inputs and outputs. The implementation 3 charging method described above as well as other methods for others Battery systems such as e.g. Li-ion or RAM (chargeable alkali-manganese Batteries) is therefore inexpensive realizable. Instead or in addition to the entrance for Unconstant power sources, the device itself can also be a self-sufficient Power source, e.g. a solar generator. This is one advantageous development of the invention as a mobile device with at least a rigid or hinged solar module and one from the sun remote control unit with battery compartment possible.

Since defined to start the operating mode 1 discharged batteries must be inserted, an additional user-activated discharge can be provided. Otherwise, the discharge takes place in externally connected consumers, as a further development of the invention, a DC-DC converter with a constant output voltage for the defined supply of externally connectable consumers can be provided. The output voltage can also be controlled to adapt to different consumers. For typical small devices such as mobile phones, organizers or GPS devices operating or charging voltages in the range of about 5 to 12 volts are needed.

In order to adapt the control electronics at least partially to the used batteries and thus to exclude a possible misconduct, a setting possibility of at least one of the variables I _const , I _max , I _tr , I _{L, max} , I _{L, min} , Q _lim depending on the housing size and / or the capacity and / or the number of inserted batteries are provided. As an example of NiMH battery housing sizes and corresponding capacities AA batteries (mignon) with about 1.0 to 2.2 Ah can be called, in contrast, reach NiCd AA batteries only about 500 to 900 mAh. For example, to charge AA batteries of both systems NiMH and NiCd in a battery compartment, a capacitance range of 500 to 2200 mAh must be covered. As a reasonable compromise for I _const for error-free implementation of the -ΔU charging method in operating mode 1, a range of about 500 to 1000 mA may be mentioned, for the other modes I _max and I _tr corresponding to 600 to 1200 mA and 25 to 50 mA and Q _{lim are} 2500 mAh, I _{L, max} and I _{L, min} may be in the range between I _max and I _tr . If you now allow multiple battery compartments connected in parallel, these values should be multiplied by the number of battery compartments, otherwise either a maximum charge or capacity will result in a charge with too high currents or a minimum charge and an increase of the fixed values he follows. The necessary detection of the battery number can be done by means of two at the negative or positive pole each battery compartment arranged contacts, which are connected to each other by the contact surface of the inserted batteries. The detection terminal then leads to the control unit and causes the corresponding changeover of the values in the microcontroller. In addition, a selection of the rechargeable battery housing size by means of a gradation of the battery compartment can be made such that each type of battery is located in the appropriate part of the battery compartment with the individual contacts attached there. The detection and retransmission of the battery type to the control unit takes place as described above.

exemplary Forms of the charging method and the power supply device according to The invention will be explained in more detail with reference to the schematic figures. there shows

1a -E a comparison of the three operating modes 1 to 3 based on diagrams

2 a diagram with the values terminal voltage measured value and standard value

3 a block diagram of the universal power supply device

4 an external perspective view of the basic structure of the universal power supply device in an exemplary embodiment as a mobile solar charger.

In 1 the operating modes 1 to 3 with reference to the diagrams 1a to 1c with an exemplary course of the sizes battery terminal voltage U _kl , charging current I _L and charge Q over the time t shown. In the diagram 1a, the battery is first discharged from a charge state Q> Q ₀ to Q = Q ₀ , which can be done, for example, via a connected external load into which a discharge current -I _{Ent is} transferred from the battery. Upon reaching a defined lower voltage threshold U ₀ , which here corresponds to the lower charge threshold Q ₀ , the battery with a constant charging current I _const until reaching a negative voltage gradient (-ΔU) of the battery terminal voltage within a period .DELTA.t with constant current I _const charged and then terminated the charge or continued only with short charging current pulses with mean value I _tr to charge conservation. During the charging process, the amount of electricity is summed up and possibly multiplied by a charging factor L. This results in the illustrated values of the charge Q, where Q ₀ corresponds to an "empty" and Q ₁ corresponds to a "full" state of the rechargeable battery. Diagram 1b shows the balancing operating mode 2 in which, depending on the direction and magnitude of the charging / discharging current I _L, the current value of the charge Q is increased or reduced, again possibly taking into account a charging factor L. Upon reaching the maximum charge state Q ₁ is switched as in operating mode 1 to a trickle charging current I _tr with charging pulses. Diagram 1c shows the behavior in the operation mode 3, in which after reaching a defined minimum clamping voltage threshold U _{kl, min} of the load current I _L from a maximum value I _{L is} reduced _max until it upon reaching a defined minimum clamping voltage threshold U _{kl, min} in a constant minimum current I _{L, min} passes, with which the battery can be easily overloaded. Nevertheless, after reaching a defined charge limit Q _lim is in turn switched to a trickle charge _current I _tr .

2 clarifies the determination of the previously described standard terminal voltage U _{kl, norm} from the measured value U _{kl, mess} and the parameters charging / discharging current I _L and temperature T according to U _{kl, norm} = U _{kl, mess} - R _i (T) · I _L. With a precise knowledge of the internal resistance R _{i of} the battery, this results in a stable, "normalized" voltage despite significant fluctuations in the measured terminal voltage value U _kl value "U _{kl, norm} , which corresponds to the charging state-dependent terminal voltage of the unloaded battery and thus can be used eg for detecting the battery state of charge.

3 shows a block diagram of the universal power supply device ( 1 ) with their essential functional components. In a housing G are an integrated generator ( 2 ), in the exemplary embodiment a solar generator, a control unit ( 5 ) with subdivision into power controller ( 11 ), Microcontroller with temperature sensor ( 10 ) and output DC / DC converters ( 9 ), Batteries ( 4 ) with battery contacts ( 4a ), Input / output unit ( 8th ) as well as inputs and outputs ( 3 ) and ( 6 ) housed. While the solar generator supplies a charging current dependent on the incident light intensity as the internal primary energy source, the input ( 3 ) are connected to a constant external power source to ensure safe operation in operating mode 1. The activation of the three different operating modes and, in general, a charging process of the internal batteries or a discharging process of external consumers V can be achieved via the input / output unit ( 8th ) and by the microcontroller ( 10 ) are converted to the connected peripherals; Alternatively, the activation can also be detected automatically when certain operating states are detected by the microcontroller ( 10 ) respectively. The output elements in the input / output unit ( 8th ), the current operating modes, the battery state of charge and other processes such as current flow in input ( 3 ), Current flow in output ( 6 ) and formed, for example, from LEDs or an LCD display. As a microcontroller, for example, a freely programmable 8-bit controller can be used, which requires an integrated or externally connected temperature sensor for switching off when certain battery-specific temperature ranges. The conversion of the analog measured values of charge / discharge current, battery voltage, etc. can be in a microcontroller ( 10 ) or externally in the control unit ( 5 ) integrated analog / digital converter. The output of the control values to the power controller ( 11 ), which measures the current flow from the internal and external power sources ( 2 ) and ( 3 ) and in or out of the batteries ( 4 ), can also be controlled via a microcontroller ( 10 ) or an external digital / analog converter. The solar generator ( 2 ) must be dimensioned so that the batteries ( 4 ) can be charged in any state of charge and the generator is in a favorable operating point. The output side DC / DC converter ( 9 ) is used to generate different output voltages from the battery voltage with high efficiency to different consumers V ( 12 ) to be able to operate. The converter can be controlled by the microcontroller ( 10 ) are switched on and off and additionally controlled in its voltage or current values.

In 4 the power supply device is shown in an exemplary embodiment as a mobile solar charger. The solar generator ( 2 ) hinged on the housing G to a shading of the battery compartment ( 7 ) ( 4 ) to effect. On the outer surfaces of the housing G are an input jack ( 3 ), an output jack ( 6 ) as well as inputs and

Output elements ( 8th ) appropriate. The entire control electronics ( 5 ) is located inside the power supply unit ( 1 ).

1

self-sufficient Power supply

2

solar generator

3

connection for one external energy source

4

Backup batteries, batteries

4a

battery contacts

5

control electronics

6

connection for one external consumer

7

battery

8th

Input / output elements

9

DC converter

10

microcontroller with temperature sensor

11

power controllers

12

external consumer

DC

DC

G

casing

I _{L, min} , I _{L, max}

minimum, maximum charging voltage

I _L , I _Ent

Charge / discharge current, discharge

I _tr

Trickle charge current

I _const

constant current

.mu.C

microcontroller

Q ₀ , Q _lim , Q ₁

Charge thresholds, amount of charge

.delta.t

Period of time

U ₀

lower voltage threshold

-ΔU

negative voltage drop

U _{kl, min} , U _{kl, max}

minimum, maximum terminal voltage

U _{kl, mess} , U _{kl, norm}

measured, standardized terminal voltage

V

consumer

Claims (16)

Method for charging / discharging control for power supply equipment with removable nickel cadmium and nickel metal hydride batteries with either constant or non-constant power supply, characterized by I. an operating mode 1, loaded in the existing at constant power supply by means of -ΔU charging a previously defined to the lower charge threshold Q ₀ discharged battery with the amount of charge Q _max up to an upper charge threshold Q ₁ and from Q ₁ - Q ₀ determined , the maximum capacity of the battery corresponding value Q _max is stored, II an operation mode 2, which is started after completion of the first operation mode and a charging and Entladebilanzierung performs on the basis of the determined battery capacity Q _max, the power supply may be constant or inconstant. and the value Q _{max is} deleted when the battery is removed, III. an operating mode 3, which is started when inserting a battery with undefined charge state Q> Q ₀ , wherein the charging current decreases with the terminal voltage U _{kl of} the battery and the power supply may be constant or inconsistent. Charging method according to Claim 1, characterized by the use of a charging factor L in the operating modes 1 and 2 according to Q = I _L * t / L, which is dependent on the external parameters Q / Q _max (charging state), I _L (charging current) and T _ak ( Battery temperature) and can optionally be used as a constant average. Charging method according to claim 1 or 2, characterized by the resetting of the charge counter to its minimum value after discharge of the battery up to a defined lower charge threshold Q ₀ . Loading method according to one of claims 1 to 3, characterized by the transition of the operating modes 1 and 2 after reaching the maximum state of charge in a trickle charge mode with a typical adapted to the determined battery capacity mean trickle charge current I _tr . Charging method according to one of claims 1 to 4, characterized by balancing the charging current in the operating mode 3 and the transition to a trickle charge mode with a typical, adapted to the determined battery capacity average trickle charge current I _tr after reaching a preset maximum charge value Q _lim , at least the value corresponds to the maximum expected battery capacity. Charging method according to one of claims 1 to 5, characterized by a decrease of the charging current I _L in the operating mode 3 of a maximum value I _{L, max} from reaching a first terminal voltage _threshold U _kl1 to a minimum value I _{L, min} upon reaching a second terminal voltage _threshold U _kl2 . Charging method according to one of claims 1 to 6, characterized by a normalization of the measured terminal voltage U _{kl, mess} to a largely independent of the parameters charging current I _L and temperature T value according to U _{kl, norm} = U _{kl, mess} - R _i (T) · I _L , where the value R _{i represents} the sum of the battery internal resistance and all external resistors in the charging circuit. Charging method according to one of Claims 1 to 7, characterized by the use of an open terminal voltage U _{kl, oc} measured in the de-energized state instead of the measured variables U _{kl, mess} or U _{kl, norm} for at least one of the operating modes 1 or 3. Charging method according to one of Claims 1 to 8, characterized by a limitation of the charging voltage in all operating modes to a value U _{kl, max} which corresponds to a value recommended for rechargeable alkaline manganese batteries (RAM). Power supply device for nickel-cadmium and nickel-metal hydride batteries with either constant or non-constant power supply, characterized by - control electronics ( 5 ) in particular with one of the charging methods described in claims (1) to (9), - a battery compartment ( 7 ) for removable batteries ( 4 ), - at least one input ( 3 ) for constant or non-constant power sources, - a connection for external consumers ( 6 ). Power supply device according to claim 10, characterized by a user-activated discharging device of the inserted batteries ( 4 ). Power supply device according to claim 10 or 11, characterized in that the user-activatable discharge device consists of a DC-DC converter ( 9 ) with a constant output voltage for the defined supply of externally connectable consumers ( 12 ) consists. Power supply device according to one of Claims 10 to 12, characterized by an adjustment possibility of at least one of the variables I _const , I _max , I _tr , I _{L, max} , I _{L, min} , Q _lim as a function of the housing size and / or the capacitance and / or the number of inserted batteries ( 4 ). Power supply device according to one of claims 10 to 13, characterized by a selection of the rechargeable battery housing size by means of a gradation of the battery compartment ( 7 ) such that each type of battery in the appropriate part of the battery compartment with the individual contacts ( 4a ) lies. Power supply device according to one of Claims 10 to 14, characterized by a detection of an inserted battery by means of two contacts arranged at the negative or positive pole of each battery compartment ( 4a ), through the contact area of the inserted battery ( 4 ). Power supply device according to one of Claims 10 to 15, characterized by a design as a mobile device ( 1 ) with at least one rigid or hinged solar module ( 2 ) and a remote from the sun control unit ( 5 ) with battery compartment ( 7 ).