Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M10/00—Secondary cells; Manufacture thereof
  • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
  • H01M10/44—Methods for charging or discharging
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
  • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
  • H02J7/007—Regulation of charging or discharging current or voltage
  • H02J7/00711—Regulation of charging or discharging current or voltage with introduction of pulses during the charging process
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
  • Y02E60/10—Energy storage using batteries

Definitions

• the present invention relates to a method and an appa ⁇ ratus for recharging or " regenerating dry batteries, espe ⁇ cially such types of dry batteries which hereto have not been considered rechargeable.
• the dry batteries are re ⁇ charged by one period of an intermittently pulsating alter ⁇ nating current, and the batteries are allowed to become discharged somewhat during the periods of time which are present between the charging pulses.
• Dry batteries generally have electrodes of zinc and carbon and between the said electrodes and electrolyte, and they are marketed as ordinary rod batteries for high load during a short period of time, for instance for flash lights etc., as radio batteries or transistor batteries intended for relatively low load during a long period of time.
• the batteries are re ⁇ charged by alternative current so that the positive period of pulsating alternative current is applied to the battery as an intermittently pulsating charge current whereas the
• O Pl inner resistance of the batteries has increased from 1,13 ohm to 3,50 ohm.
• the batteries now recharged were allowed to stand for three hours after the recharging was ended.
• the open circuit voltage had stabilized at 10,00 V and the said voltage was kept for a long following period of time.
• figure 1 of the drawings is shown a circuit diagram of a simple apparatus for executing the method according to the invention.
• Figure 2 shows a curve illustrating the charge voltage and drawn from an oscillograph.
• Figure 3 is a diagram which schematically illustrates the voltage variations of a battery cell when being charged, in fully charged but non-loaded state and during load res ⁇ pectively.
• Figure 4 is a diagram illustrating the function of a Zener-diode included in the apparatus according to figure 1
• figure 5 is a circuit diagram of a more developed and automatically acting battery charger.
• the apparatus illustrated in figure 1 is the very apparatus which was used in the above mentioned experiments.
• the charging apparatus includes a transformer which is not shown in the drawings and which gives 24 V alternate current voltage over the pole terminals 1 and 2.
• the charging mainly is made by the positive period of the alternate voltage, and the apparatus is designed for the best possible charging of dry batteries of the type R 14.
• a diode Dl for instance a silicium diode of 0,5 A is connec ⁇ ted, and paralleUy over the said diode a large resistance R 1 of 470 ohm and 1 W is connected.
• the diode D 1 and the resistance R 1 are both connected to a conduit 3 which is connected to the positive pole of six batteries 4 each of 1,5 V which are connected in series.
• a small resistance R 2 of 21 ohm and 9 W is connected, and paralleUy over the batteries 4 connected in series is both a Zener-diode D2 having a breake through voltage of 12 V and in series therewith a so called PTC-resistance R 3 (positive temperature coefficient) of between 0' and 100 kilohm connected.
• the PCT-resistance R3 acts so as to form a very high resistance when loaded with high current, where ⁇ as the resistance decreases when the current decreases. This means that the PCT-resistance gives a high resistance when the batteries 4 have a high internal resistance, i.e. when the batteries are strongly discharged, whereupon the resistance of the PTC-resister -drops following the increased charge of the batteries. From the negative pole of the batteries extends a conduit 5 which closes the circuit at the pole terminal 2.
• the dry batteries 4 are intended to be charged with the positive periods of an alternate current and during the said periods a current flows from the pole terminal 1, over the diode Dl, through the conduit 3 and the little resist ⁇ ance R2 and through the batteries 4 and the current is closed over the conduit 5 at t-he pole terminal 2. Since only the positive period is used the maximum-voltage during the period is half the transformer voltage of 24 V, conse- quently 12 V, which is 33 % over the nominal voltage of the batteries. Since the resistance R1 is large practically all current flows through the diode Dl.
• the Zener-diode D2 has a brake through voltage of 12D, but still a small amount of current passes through the diode, and the higher resistan- ce of the batteries 4 is the higher current should pass through the Zener-diode D2 if it was not connected in series with the PCT-resistance R3.
• the resistance of the PTC-resistor R3 is very high if the batteries are strongly discharged and therefore practically no current will pass through the unit of the PTC-resistor R3 and the Zener- diode D2. In the discharged state the batteries 4 therefore are loaded with a strong current what is necessary to over ⁇ come the inner resistance of the batteries so as to force any charging current through the batteries.
• FIG. 2 shows three positive charging pulses 7 over the zero-line and Between the discharging pulses 8 which re ⁇ present the discharging which is allowed from the batteries during the periods between the charging pulses.
• the current circuit is closed over the pole terminal 1 and the transformer, over the pole ter ⁇ minal 2 and the conduit 5.
• the discharging pulse 8 which is oppositely directed to the charging pulse 7 extends as a negative pulse 8 on an oscillograph. Since the discharging pulse is substantially less than the charging pulse 7 the main part of the charge is remained in the battery cells.
• the diode D2 opens fully, and since the battery cells thereby do not accept further charing the resistance of the resistor R3 increases.
• the output of cur ⁇ rent drops, and since the Zener-diode D2 is open any possib ⁇ le current passes the diode D2 and the resistor R3. The battery cells 4 consequently are disconnected from the charging circuit.
• Zener-diode D2 and the resistor R3 thereby prevent any overload of the batteries. If the battery voltage by time should drop the Zener-diode closes and the resistance of the PTC-resistor- increases and charging pulses are once again fed into the batteries until the voltage of the batteries once again reach a value corresponding to the brake through voltage of the Zener-diode D2.
• figure 2 is illustrated by dotted lines how the peaks of the charging pulses are" somewhat cut off as the voltage over the battery shells increases, and figure 2 correspondingly illustrates how the voltage of the dis- charging pulses increases.
• FIG 3. is diagrammatically illustrated the vol ⁇ tage function of a battery cell of 1,5 V during charging, a subsequent rest period and a further subsequent discharging period. In the diagram it is presupposed that the recharging starts when the battery cell has an .orbit circuit voltage of
• the large resistor Rl has for its main purpose to restrict the discharge current from the batteries and the little resistor R2 is intended for adapting the charge current for different types of batteries. For batteries having a large capacity only a little resistance is used or the resistor R2 is simply excluded and for batteries having a little capacity a relatively large resistance of R2 is used.
• the resistor R had a value of 470 ohm whereas the little resistor R2 had a value of 27 ohm. This gave a recharging current of about 150 mA.
• the PTC-resistor R3 had a working area from 0 to 100 kilohm, and the Zener-diode D2 was of the type IN 5927.
• the resistor R2 can be formed as a variable resistor, and in such case preferably an ampere meter is mounted in direct connection to the resistor to make it possible to check that the charging current is within the optimum value of 75-175 mA.
• FIG 4 is diagram atically illustrated the func ⁇ tion of the Zener-diode D2 as far as to the breake through voltage of 12 V and without reference to the resistor R 3 connected in series with the said diode.
• a re- latively weak current is capable of passing in the break through direction up to about 7 V, whereupon a slightly increasing current passes as far as to 12 V, whereby the diode opens completely and the current can pass through the diode practically without any resistance.
• FIG 5 is shown an alternative embodiment of a recharging apparatus for executing the method according to the invention.
• the said apparatus is intended to be con ⁇ nected to 220 V alternate 'current and it comprises a trans ⁇ former 10 which transforms the current to a suitable charg- ing current, for instance 24 V alternate current, for re ⁇ charging six dry batteries 4 each of 1,5 V connected in series.
• a trans ⁇ former 10 which transforms the current to a suitable charg- ing current, for instance 24 V alternate current, for re ⁇ charging six dry batteries 4 each of 1,5 V connected in series.
• a large resist ⁇ or R 1 is connected, and in series therewith a weak resistor R 2. ParalleUy over the resistor R 1 a diode Dl for instan- ce a silicium diode is connected, and paralleUy over the weak resistor R 2 a capacitor-C is connected.
• the diode Dl and the capacitor C are connected in common to a point 11 and the output of the capacitor Cl is connected to the out ⁇ put of the little resistor R2 at a point 12.
• a two-pole connection relay Rel and a one-pole disconnection relay Re2 To the same point 12 are connected the battery cells 4 to be recharged, a two-pole connection relay Rel and a one-pole disconnection relay Re2.
• the opposite ends of the battery cells 4, the connection relay Rel and the disconnection relay Re2 are interconnected over a conduit 16, and paralleUy over the battery cells are connected a Zener-diod D2 and a PTC- resistor R3 from point 12 to a point 13. From point 13 three conduits are branched, viz.
• a first conduit 14 which is connected to the pole terminal 2 of the transformal 10 and which contains a fuse 15, a second conduit 16 which contains a check lamp LI indicating that charging is on and a third conduit 17 containing a check lamp L2 normally indicating that the batteries 4 are fully charged.
• the lamps LI and L2 are commonly connected to the pole terminal 1 of the transformer 10 over a conduit 18.
• the conduit 18 contains a diode D3 which with the anode portion is connect ⁇ ed to the pole terminal 1 of the transformer. ParalleUy over the connection relay Rel a capacitor Cl is connected and paralleUy over the disconnection relay Re2 a capacitor C2 is connected.
• the con ⁇ nection relay Rel is connected after the battery cells 4 and the disconnection relay Re2 following the connection relay Rel.
• a diode D4 is connected between the battery cells 4 and the connection relay Rel, and between the connection relay Rel and the disconnection relay Re2 a variable resist ⁇ or R4 is connected for controlling the disconnection voltage of the disconnection relay Re2.
• the two-pole connection i - relay Rel contains two switches 19' and 20 which are dis- connected when the relay Rel is non-actuated. The switch
• the one-pole disconnection relay Re2 contains a switch 21 which is connected by the conduit 17 to the check lamp L2 and which is disconnected when the relay Re2 is disconnected.
• the diodes Dl, D3 and D4 may be of any type, for inst ⁇ ance silicium diodes, whereas the diode D2 is of the Zener type and has a breake through voltage which is about one third higher than the nominal voltage over the battery cells 4.
• the Zener-diode preferably should have a breake through voltage of 12 V.
• Both relays Rel and Re2 have a permitted operation voltage corresponding to the maximum charging voltage, in the above mentioned case 12 V, but at least the connection relay Rel should have a connection voltage which is the same as or less than the lowest voltage at which it may be possible to start the charging.
• the resistors Rl and R2 are adapted to the batteries to be recharged, and when recharging battery cells having a rated voltage of 9 .
• V the resistor Rl is preferably chosen 470 ohm and the resistor R2 27 ohm.
• the resistor R4 is a- variable resistor which can be controlled for instance between 10 and 2200 ohm, and the resistor R3, which is a PTC-resistor, can be designed for an acting field of between 0 and 100 kilohm.
• a resistor R5 can be connected paralleUy over the battery cells-4 via a switch 22 as will be further explained in the following.
• the battery cells are connected between the conduits 19 and 16 with the anode facing the conduit 19. If the pole voltage over the batteries is less than the connection voltage of the connection relay Rel the contact 20 thereof intftfe .main conduit 14 remains disconnected and no current can flow into the apparatus. Both check lamps LI and L2 thereby remain turned off. If, however, the pole voltage over the batteries 4 exceeds the connection voltage of the connection relay Rel, which in the above mentioned case is 3 V the relay Rel turns over to connected state and the switches 19' and 20 are connected.
• Discharging During the periods between the intermittent charging pulses a discharge current is allowed to pass from the batte ⁇ ry cells 4 to the little resistor R2, the large resistor Rl, over the transformer 10 and through the main conduit 14 back to the battery cells 4. ParalleUy herewith a current flows through the diode D4, through the connection relay Rel and back to the battery cells 4, which current keeps the main switch 20 connected.
• the PTC-resistor R3 and the Zener-diode D2 connected in series therewith prevent current from passing therethrough when the battery cells 4 are strongly discharged. As the charge of the battery cells increase the inner resistance thereof decreases and thereby also the resistance of the PTC-resistor R3 decreases and by time some charging current can pass through the conduit 23 containing the said two components.
• the counter electromotive force thereof is so strong that the voltage over the battery poles reach the level of the connection voltage for the relay Re2.
• the connection voltage thereof can be adjusted by the variable resistor R4.
• the relay Re2 connects and the switch 21 in the conduit 17 is closed whereby the check lamp L2 lights and thereby indicates that the batteries 4 are fully charged.
• the resistance of the PTC-resistor R3 has reached its maximum level, and also the breake through voltage for the Zener-diode is reached.
• the charging apparatus according to the invention also can be used for charging of.ordinary rechargable batteries and accumulators like rechargeable nickle-cadmium accumulators or silver-zinc accumulators. It is to be understood that the above described method and the apparatus described above and shown in the drawings is not restricting the invention and that all kinds of modifications may be presented within the scope of the appended claims.

Landscapes

• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Electrochemistry (AREA)
• General Chemical & Material Sciences (AREA)
• Power Engineering (AREA)
• Charge And Discharge Circuits For Batteries Or The Like (AREA)
• Secondary Cells (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=20334904

Family Applications (1)

Country Status (5)

Families Citing this family (10)

Family Cites Families (3)

• 1978
  • 1978-05-12 SE SE7805501A patent/SE408610B/sv unknown
• 1979
  • 1979-04-12 JP JP50066079A patent/JPS55500324A/ja active Pending
  • 1979-04-12 GB GB7935619A patent/GB2040119B/en not_active Expired
  • 1979-04-12 WO PCT/SE1979/000091 patent/WO1979001061A1/en unknown
  • 1979-12-17 EP EP79900408A patent/EP0015951A1/de not_active Withdrawn

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events