Preservation device for lead storage battery

The present invention discloses a preservation device for lead storage battery comprising: a lead storage battery including at least one negative plate, at least one positive plate, at least one separator between said negative and positive plates, an electrolyte holdingly impregnated by said negative & positive plates and said separator and limited in amount such that substantially there is no electrolyte liberated from said negative & positive plates and said separator, and external terminals having one ends respectively connected to said negative and positive plates and the other ends exposed to the outside of the lead storage battery vessel; and an impedance means connected between said external terminals of said lead storage battery during its preservation. Such preservation device permits to prevent a battery preserved in such device from being decreased in capacity without requiring troublesome maintenance such as supplementary charging at regular intervals, even if it is preserved for a long period of time.

FIELD OF THE ART 
The present invention relates to a preservation device for lead storage 
battery, and more particularly, a preservation device for a so-called 
retainer-type lead storage battery having an electrolyte limited in amount 
such that substantially there is no liberated electrolyte. 
BACKGROUND OF THE INVENTION 
In a retainer-type lead storage battery, the electrolyte is limited in 
amount and the negative electrode has capacity larger by 10-30% than that 
of the positive electrode. Accordingly, when the battery is charged, the 
positive electrode is fully charged before the negative electrode. Oxygen 
generated from the positive electrode due to overcharge is absorbed and 
consumed by the negative electrode. 
After assembly, lead storage batteries of this type are generally subjected 
to forming and then delivered or preserved in a full-charge state. Until 
they are put to actual use, it is required that they are supplementarily 
charged at regular intervals, for example every six months and preferably 
every three months, in order to preserve such batteries at all times 
substantially in a full-charge state. 
Lead storage batteries generally undergo self-discharge of about 0.1-0.15% 
of the battery capacity for every day, thereby to reduce their capacity 
due to self-discharge of 20-30% for a period of six months. 
If a discharge product produced by self-discharge of a battery can be 
activated by charging or if the battery capacity can be restored, it is 
not required to supplementarily charge the battery so often. However, when 
a battery is left in a self-discharge state for a long period of time, a 
discharge product or lead sulfate (PbSO.sub.4) is inactivated, thereby to 
reduce the charging efficiency. Accordingly, the capacity cannot be 
sufficiently restored to provoke a decrease in battery characteristic, 
thus requiring frequent maintenance of supplementary charge. Such 
maintenance is not only troublesome, but also includes the problem that 
the battery capacity cannot be fully restored even with repeated 
supplementary charge. 
FIG. 1 is a graph of self-discharge characteristics showing the capacity 
rates to an initial battery capacity of the battery capacity where the 
batteries were discharged at room temperature (20.degree. C.) after 
leaving for various periods of time under such discharging condition that 
they were discharged with a current corresponding to 0.1 c and stopped 
discharging when the voltage of battery was reached 1.7 V. 
FIG. 2 is a graph of the capacity reset characteristics showing the 
capacity reset rates to an initial battery capacity of the battery 
capacity where the batteries were charged with a constant voltage (2.5 V) 
for 16 hours and then discharged with the above discharge condition, after 
leaving for various periods of time. 
In FIG. 1 and FIG. 2, the initial capacity of battery which was discharged 
immediately after forming under the above discharge condition, is defined 
as 100%. 
According to the studies of the inventor and other, batteries are slowly 
decreased in voltage by self-discharge when they are left after subjected 
to forming. With such self-discharge, there are chemically bonded 
Pb.sup.++ ions in the corrosion layer of lead dioxide (PbO.sub.2) on the 
surface of the collector member or Pb.sup.++ ions of the active material 
PbO.sub.2 with SO.sub.4.sup.-- ions in the H.sub.2 SO.sub.4 electrolyte, 
thereby to produce lead sulfate (PbSO.sub.4). When batteries are left for 
a long period of time, such lead sulfate (PbSO.sub.4) easily becomes 
inactivated. This decreases the charging efficiency when batteries are 
re-charged, so that the capacity cannot be fully restored to deteriorate 
the battery characteristics. Such deterioration becomes greater as the 
supplementary charging cycle period is longer or batteries are left for a 
longer period of time. Such deterioration is further accelerated when 
batteries are left in a high temperature atmosphere. 
OBJECT OF THE INVENTION 
It is an object of the present invention to provide a preservation device 
for lead storage battery capable of preventing a battery preserved in such 
preservation device from being deteriorated in characteristics without 
requiring troublesome maintenance such as supplementary charging at 
regular intervals, even though it is left and preserved for a long period 
of time. 
DISCLOSURE OF THE INVENTION 
A preservation device for lead storage battery in accordance with the 
present invention comprises: a lead storage battery having at least one 
negative plate, at least one positive plate, at least one separator 
between these plates, an electrolyte holdingly impregnated by the both 
plates and the separator and limited in amount such that substantially 
there is no electrolyte liberated from these plates and separator, and 
external terminals each having one end respectively connected to the 
negative plate and positive plate and the other ends exposed to the 
outside of the battery vessel; and impedance means connected between the 
external terminals of the lead storage battery while it is preserved.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The description hereinafter will be made of one example of a lead storage 
battery applied to the present invention, with reference to FIG. 3 showing 
the section view thereof. 
A lead storage battery 1 is made in the following way. 
A lead-calcium alloy is subjected to casting, punching or expanding, and 
cut into a piece of 50.times.50.times.1 mm as a negative collector member 
2 and a piece of 50.times.50.times.2 mm as a positive collector member 3. 
An active material paste of lead monoxide (PbO) and water, is rolled by a 
roller, so that active material layers of 50.times.50.times.0.7 mm and 
50.times.50.times.1.0 mm are formed. These sheet-like active material 
layers are respectively contact-pressed to the negative collector member 2 
and the positive collector member 3 at the both sides thereof, thereby to 
form a negative plate 4 and a positive plate 5. The final negative plate 4 
has a thickness of 1.2 mm, while the final positive plate 5 has a 
thickness of 2.4 mm. 
An electrode assembly is formed by putting alternately one positive plate 5 
and two negative plates 4 made as discussed above, with glass fiber 
separators 6 disposed between the positive plate 5 and the negative plates 
4. This electrode assembly is disposed in a battery jar of resin 7. 
An amount of 10 cc of a sulphuric acid electrolyte having specific gravity 
of 1.30 is poured into the jar 7. After the electrolyte has been holdingly 
impregnated by the negative plates 4, the positive plate 5 and the 
separators 6, a battery jar lid 8 having a negative external terminal 9 
and a positive external terminal 10 is mounted to the battery jar 7, thus 
forming a lead storage battery having capacity of 1 AH. Such lead storage 
battery may be used after subjected to forming. The vessel consists of 
said jar 7 and jar lid 8. 
The present invention provides a preservation device for preserving such 
lead storage battery with an impedance means made by resistance for 
example, being connected between the external terminals 9 and 10 of the 
battery 1. 
This impedance means is preferably set to such value that a lead storage 
battery housed in the preservation device discharges with a current 
smaller than that corresponding to the 5-hour rate (0.2 c). In the 
embodiment, there is connected resistance of 20 ohms corresponding to the 
0.1 c current of the lead storage battery 1. 
Comparison is then made in performance between the lead storage battery A 
preserved in the preservation device according to this embodiment, and 
comparative lead storage batteries B, C and D preserved with their 
external terminals opened for the comparison purpose. 
The comparative lead storage battery B discharged with a constant current 
corresponding to 0.1 c until the discharge stop voltage (1.7 V) was 
reached. The battery B was thereafter preserved with the external 
terminals opened. In the battery B, the self-discharge rate is 
substantially 100%. 
The comparative lead storage battery C discharged by 0.5 AH with a constant 
current corresponding to 0.1 c and then preserved with the external 
terminals opened. In the battery C, the self-discharge rate is 
substantially 50%. 
The comparative lead storage battery D was preserved with the external 
terminals opened immediately after subjected to forming. 
Tests and measuring were conducted under simulation of various 
self-discharge rates of the lead storage batteries A,B,C and D preserved 
for a long period of time. Namely, after subjected to forming as charged 
for 24 hours with a current density corresponding to 1.5 A/dm.sup.2, the 
lead storage batteries A,B,C and D were left for 3 months and 6 months in 
an atmosphere of 40.degree. C. for the purpose of accelerated tests. The 
batteries A,B,C and D were then charged with a constant voltage of 2.5 V 
for 16 hours and discharged with a current corresponding to 0.1 c. 
Measurement was made on discharge capacity where the discharge stop 
voltage of 1.7 V was reached. 
FIG. 4 is a graph showing the test results as to performances of the lead 
storage battery A preserved in the preservation device of the present 
invention, and the comparative lead storage batteries B,C and D. From FIG. 
4, it is found that the lead storage battery A preserved in the 
preservation device of the present invention satisfies the rated capacity 
even after preserved for 6 months. From FIG. 4, it is also found that the 
comparative lead storage batteries B,C and D are decreased in charging 
efficiency, in particular where such batteries were charged with a 
constant voltage after preserved for a long period of time. Such decrease 
in charging efficiency is caused by the fact that, when a battery is 
preserved for a long period of time with the terminals opened, the 
corrosion layer of PbO.sub.2 produced on the positive collector surface by 
forming is transformed into Pb.sup.++ ions, and such Pb.sup.++ ions are 
reacted to and bonded with SO.sub.4.sup.-- ions remaining in the 
electrolyte, thereby to produce an inactive PbSO.sub.4 layer. Such 
reaction provokes voltage build-up at the time of charging made after the 
battery has been preserved. This results in defective charge. 
On the other hand, when a battery is left and preserved in the preservation 
device of the present invention with its impedance means connected between 
the both external terminals of the battery, a discharge current flows 
correspondingly to the discharge voltage produced due to load connection. 
Accordingly, a micro-current discharge is made at the final discharge 
stage. With discharge from the active material more advanced, the battery 
stops discharging uniformly around the plate surfaces, and the 
SO.sub.4.sup.-- ions remaining in the electrolyte are substantially 
consumed. This restrains generation of PbSO.sub.4 by SO.sub.4.sup.-- and 
Pb.sup.++ in the PbO.sub.2 corrosion layer of the collector member. 
Therefore, after left and preserved in the preservation device of the 
present invention even for a long period of time, the battery does not 
exhibit the problem that a charging current flow is decreased due to 
transformation of the PbO.sub.2 corrosion layer to PbSO.sub.4 during such 
preservation. Accordingly, a battery preserved in the preservation device 
of the present invention even for a long period of time, may be 
efficiently charged, in particular with a constant voltage, thereby to 
prevent the battery from being decreased in characteristic. 
The description will be then made of a first embodiment of the present 
invention with reference to FIGS. 5-8. 
The description firstly discusses one example of a lead storage battery 
applied to this first embodiment, with reference to FIG. 5 showing the 
exploded perspective view of such battery. 
Plate-shape collector members 13 are respectively secured to the inner 
surfaces of a resin member 11 composing a part of a battery jar, and a 
battery jar lid 12 engaged with the opening of the resin member 11. 
Each of the resin member 11 and the battery jar lid 12 is formed integrally 
with the plate-shape collector member 13 of a Pb-Ca alloy, an external 
terminal 14 and a lead wire 15 for connecting the external terminal 14 to 
the collector member 13, according to insert-molding with the use of an 
ABS resin. The external terminals 14 of negative and positive plates are 
located on the same plane. The resin member 11 has a valve chamber 16 in 
which a safety valve is disposed, a frame-shape engagement groove 18 to 
engage with a frame-shape projection wall 17 on the inner surface of the 
battery jar lid 12, and a gas hole 19 for discharging gas. 
Housed in the resin member 11 is an electrode assembly including a negative 
active material layer 21 held by a resin material 20, a separator 22 and a 
positive active material layer 24 held by a resin material 23. At this 
time, the plate-shape collector member 13 comes in contact with one side 
of the negative active material layer 21 or the positive active material 
layer 24. 
A necessary amount of a sulfuric acid electrolyte having specific gravity 
of 1.30 is poured onto the electrode assembly. Since the area of the 
electrode assembly to receive the electrolyte is relatively large, the 
inside air or a generated gas is easily substituted so that the 
electrolyte is holdingly impregnated immediately by the electrode 
assembly. 
The resin member 11 and the battery jar lid 12 are then secured to each 
other and hermetically sealed. The battery may then be used after 
subjected to forming. 
The description will then be made of the first embodiment of the 
preservation device for preserving such lead storage battery 25 of the 
thin plate shape of the present invention, with reference to FIGS. 6-8. 
A housing member 26 for housing the lead storage battery 25 includes a base 
member 27 made of a thick paper or resin for example hard vinyl chloride 
or ABS, and a transparent covering member 29 which has a peripheral edge 
attached to the base member 27 and, at the center thereof, an expanded 
portion 28 of which the shape corresponds to the shape of the lead storage 
battery 25 to be housed. Thus, the lead storage battery 25 is adapted to 
be housed as held by and between the expanded portion 28 and the base 
member 27. 
The base member 27 has, at the positions thereof corresponding to the both 
external terminals 14 of the lead storage battery 25, contact members 30 
secured thereto adapted to respectively come in contact with the both 
external terminals 14. Connected between the both contact members 30 is an 
impedance means comprising an impedance element 31 such as resistance. 
This impedance element 31 is formed by, for example, a printed resistance, 
and secured to the base member 27. For example, a printed resistance or 
the like is seucred to the base member 27 as printed thereon. As shown in 
FIG. 9, resistance 32 or the like may also be secured to the reverse side 
of the base member 27. 
The base member 27 has a perforation 33 or the like to facilitate the 
removal of the lead storage battery 25 from the housing member 26. 
When the lead storage battery 25 after subjected to forming, is housed in 
the housing member 26, it means that the impedance element 31 such as 
resistance is connected, through the both contact members 30, between the 
external terminals 14 of the lead storage battery 25. 
After preserved in such state, the lead storage battery 25 may be removed 
from the housing member 26 and charged when it is actually used. Thus, 
such lead storage battery may be used with its original characteristics 
not deteriorated without requiring any maintenance such as supplementary 
charging. 
The description will then be made of a second embodiment of the present 
invention with reference to FIGS. 10-12. 
Likewise the first embodiment in FIG. 6, a housing member 34 for housing 
the lead storage battery 25 shown in FIG. 5, includes a base member 35 and 
a covering member 37 having a peripheral edge attached to the base member 
35 and, at the center thereof, an expanded portion 36 of which the shape 
corresponds to the shape of the lead storage battery 25. The lead storage 
battery 25 is housed in the housing member 34 as held by and between the 
expanded portion 36 and the base member 35. 
The base member 35 has a projection wall 38 for positioning the lead 
storage battery 25. According to press machining, this projection wall 38 
is formed into a frame shape so as to surround the lead storage battery 
25. The base member 35 has on the reverse side thereof a concave portion 
39. 
The base member 35 has, at the positions thereof corresponding to the both 
external terminals 14 of the lead storage battery 25, contact members 40 
secured thereto adapted to respectively come in contact with the external 
terminals 14. An impedance element 41 similar to that in FIG. 6, is 
connected between these contact members 40. This impedance element 41 is 
formed by a printed resistance or the like and secured to the base member 
35. For example, a printed resistance or the like may be secured to the 
surface of the base member 35 as printed thereon, or resistance may be 
secured to the reverse side of the base member 35. In this second 
embodiment, the impedance element 41 is disposed in a hollow portion 42 of 
the projection wall 38. Such arrangement enables the projection wall 38 to 
also serve as a protection wall of the impedance element 41. 
The base member 35 has a perforation 43 or the like to facilitate the 
removal of the lead storage battery 25 from the housing member 34. 
Although the projection wall 38 is made hollow in the second embodiment, 
the projection wall 38 is not limited to the hollow construction but may 
be formed into any shape as far as it can position the lead storage 
battery 25. 
According to the second embodiment, the impedance element 41 can be 
securely connected automatically between the both external terminals 14 of 
the lead storage battery 25 when the lead storage battery 25 is housed and 
preserved in the housing member 34 as positioned by the projection wall 38 
of the base member 35. 
According to the second embodiment, the positioning projection wall 38 may 
also serve as a protective wall of the impedance element 41 since the 
impedance element 41 is disposed in the hollow portion 42 of the 
projection wall 38. 
The description will then discuss a third embodiment of the present 
invention with reference to FIGS. 13-17. 
A base member 45 of a housing member 44 for housing the lead storage 
battery 25 in FIG. 5 is made of a thin plate of an opaque resin such as 
vinyl chloride or an ABS resin. The base member 45 has, on its four sides, 
cut-up pieces 46, 47a, 47b and 47c located outside of the positions 
corresponding to the external shape of the lead storage battery 25 when 
placed on the base member 45. The cut-up piece 46 has a pair of terminal 
receiving members for coupling 49 between which a chip resistance 48 
constituting an impedance means is disposed. These terminal receiving 
members 49 and the chip resistance 48 are attached to the surface of the 
cut-up piece 46 and connected to each other by a printed pattern 50 
including contact members. 
FIG. 15 shows the base member 45 with the cut-up pieces 46, 47a, 47b and 
47c not raised up. As shown in FIG. 15, the cut-up pieces 47a, 47b and 47c 
respectively have slits 51a, 51b and 51c at the longitudinal centers 
thereof. These cut-up pieces 46, 47a, 47b and 47c are raised up toward the 
surface of the base member 45 as shown in FIG. 14. At this time, the chip 
resistance 48 and the terminal receiving members 49 are inwardly turned. 
After raised up, the cut-up pieces 47a, 47b and 47c are inwardly turned by 
the respective slits 51a, 51b and 51c, thereby to form three pairs of 
resilient pieces 52a, 52b and 52c. 
The lead storage battery 25 is then housed in the space defined by the 
cut-up pieces 46, 47a, 47b and 47c. At this time, the chip resistance 48 
is electrically connected to the external terminals 14 of the lead storage 
battery 25 through the printed circuit pattern 50. The resilient pieces 
52a, 52b and 52c are effective in securely fixing the lead storage battery 
25. 
The lead storage battery 25 thus fixed to the base member 45 with the chip 
resistance 48 connected between the external terminals 14, is covered with 
a covering member 53 and hermetically sealed. The covering member 53 is 
made by vacuum-molding of a transparent styrol resin, and is attached to 
the base member 45 by adhesives or pressingly sticked thereto by heating. 
According to the third embodiment, the impedance means is not embeded in 
resin according to insert-molding or the like. Thus, the impedance means 
is neither applied by heat generated during molding nor an excesive 
pressure due to contraction after molding, thereby to improve the 
reliability of the impedance means. 
The cut-up piece 46, 47a, 47b and 47c or the resilient pieces 52a, 52b and 
52c may push the lead storage battery 25 in the inner direction of the 
housing member 44. Such construction prevents the lead storage battery 25 
from positionally shifting in transit. It is therefore possible to 
maintain impedance-connection of the lead storage battery 25 in the 
optimum condition. 
The description will then be made of a forth embodiment of the present 
invention with reference to FIGS. 18-20. 
A board 54 is disposed to face to the external terminals 14 of the lead 
storage battery 25 and has contact members 55 printed thereon at the 
positions thereof corresponding to the external terminals 14. Disposed 
between these contact members 55 is an adhesive tape resistance 56 
constituting an impedance means. This adhesive tape resistance 56 is 
electrically connected to the contact members 55 through connection 
members 57 printed on the board 54. After the circuit has been printed on 
the board 54 by etching or the like, the adhesive tape resistance 56 is 
attached to the board 54, which is then subjected to printing in a 
pyrostat of 300.degree. C. for 5-6 hours, so that the adhesive tape 
resistance 56 is fixed to the board 54. 
After subjected to forming, the lead storage battery 25 is housed in a 
housing member 58 with the board 54 attached to that surface of the lead 
storage battery 25 on which the external terminals 14 are disposed. The 
housing member 58 includes a plate-shape base member 59 made of a 
transparent resin, for example vinyl chloride or an ABS resin, and a 
covering member 60 made by vacuum-molding of a transparent styrol resin. 
The covering member 60 is attached to the base member 59 by adhesive or 
pressingly sticked thereto by heating. Such sealed lead storage battery is 
delivered from the factory and preserved at retail shops or the like. 
After the adhesive tape resistance 56 has been attached to the base member 
59, the portion of the board 54 including the resistance 56 and the 
contact members 55 may be broken away and raised upward from the base 
member 59 so as to face to the lead storage battery 25. 
According to the forth embodiment of the present invention, the contact 
members 55 and the adhesive tape resistance 56 are disposed on the inner 
surface of the covering member 60, so that it is not required to embed the 
impedance means into the base member according to insert-molding or the 
like. Thus the impedance means is neither applied by heat generated during 
molding nor an excessive pressure due to contraction after molding, 
thereby to improve its reliability. 
The board 54 having the impedance means may be formed as an independent 
member. In such case, when a lead storage battery is to be preserved as 
removed from the housing member 58, the adhesive tape resistance 56 may be 
attached to that portion of the lead storage battery on which the external 
terminals 14 are disposed. Thus, impedance-connection may be easily 
provided. 
The description will then be made of a fifth embodiment of the present 
invention with reference to FIGS. 21-23. 
According to this fifth embodiment, a lead storage battery 61 to be housed, 
has external terminals 62 projected from the battery vessel. The lead 
storage battery 61 is housed in a housing case 63 of which the top is 
opened. The housing case 63 has a concave portion 64 for housing the lead 
storage battery 61, and two grooves 65 at the tip of the case 63. Disposed 
in the grooves 65 are terminal receiving members 66 to come in contact 
with the external terminals 62. The terminal receiving members 66 have 
resiliency to facilitate the insertion of the external terminals 62 
therein. 
The housing case 63 has therein an impedance means 67 connected to the 
terminal receiving members 66. The housing case 63 has, at the rear end 
thereof, a resilient piece 68 which applies spring-load to the lead 
storage battery in the direction toward the terminal receiving members 66. 
The housing case 63 is made of resin such as ABS or polypropylene and 
formed integrally with the terminal receiving members 66 and resistance as 
the impedance means 67 according to insert-molding. 
According to this fifth embodiment, with the external terminals 62 of the 
lead storage battery 61 inserted into the terminal receiving members 66, 
the lead storage battery 61 is housed in the concave portion 64. The 
impedance means 67 is thus connected between the external terminals 62 
through the terminal receiving members 66. 
The description will then be made of a sixth embodiment with reference to 
FIGS. 24-25. 
According to the sixth embodiment, there is housed the lead storage battery 
25 of the thin plate type shown in FIG. 5. 
The lead storage battery 25 is housed in a housing case 69 of which the top 
is opened. The housing case 69 has a concave portion 70. Disposed on the 
bottom plate 71 of the concave portion 70 are terminal receiving members 
72 respectively adapted to come in contact with the external terminals 14 
of the lead storage battery 25. The terminal receiving members 72 are made 
of leaf springs to apply a upward spring-load. When inserted in the 
housing case 69, the lead storage battery 25 is held by and between a top 
plate 73 and the terminal receiving members 72 of the housing case 69 at 
its front end. Resistance 74 as an impedance means is connected between 
the terminal receiving members 72. 
The housing case 69 has at its rear end a curved surface 75 for smoothly 
guiding the lead storage battery 25 when it is inserted. The curved 
surface 75 has at its terminal end a step portion 76 to which a leaf 
spring 77 disposed in the housing case 69 at its front end, pushes the 
housed lead storage battery 25. 
Likewise the fifth embodiment shown in FIG. 21, the housing case 69 is made 
of resin such as ABS and formed integrally with the terminal receiving 
members 72, the resistance 74 and the leaf spring 77 according to 
insert-molding. 
When the lead storage battery 25 is housed in the housing case 69, the 
resistance 74 as the impedance means is connected between the external 
terminals 14 through the terminal receiving members 72. 
The housing case 69 according to the sixth embodiment of the present 
invention, enables the lead storage battery 25 to be easily housed and 
removed, and may be used any number of times for preserving the lead 
storage battery 25. 
The description will then be made of a seventh embodiment of the present 
invention with reference to FIGS. 26-31. 
A cap 78 as a mounting member is mounted to the lead storage battery 25 
shown in FIG. 5 for covering a portion thereof. The cap 78 made of a 
synthetic resin, has in the top surface thereof, a concave portion 79, in 
which a solid resistance 80 equivalent to 0.1 c is disposed as an 
impedance means. The cap 78 has, in the lower portion thereof, a concave 
portion 81 into which the lead storage battery 25 is inserted at the upper 
end thereof. The concave portion 81 has a pair of contact members 82 on 
the upper surface thereof at its positions corresponding to the external 
terminals 14 of the lead storage battery 25. These contact members 82 are 
connected to the solid resistance 80 through connection members 83 of lead 
wires. When the cap 78 is mounted on the lead storage battery 25 at its 
upper end, the contact members 82 come in contact with the external 
terminals 14. 
With the cap 78 mounted on the lead stroage battery 25 after subjected to 
forming, the lead storage battery 25 is housed in a housing member 84. The 
housing member 84 includes a plate-shape base member 85 made of a 
transparent resin such as vinyl chloride or ABS, and a covering member 86 
made by vacuum-molding of a transparent styrol resin. 
With the cap 78 mounted on the lead storage battery 25 after subjected to 
forming and the solid resistance 80 as an impedance means connected 
between the external terminals 14, the lead storage battery 25 is disposed 
on the base member 85. The covering member 86 is attached to the base 
member 85 by adhesives or pressingly sticked thereto by heating. The lead 
storage battery 25 is then preserved. 
According to this seventh embodiment, the impedance means is housed in the 
concave portion 79 of the cap 78, and is not embeded in a resin member 
according to insert-molding, etc. Thus, the impedance means is neither 
applied by heat generated during molding nor an excessive pressure due to 
contraction after molding, so that the reliability of the impedance means 
is greatly improved. 
Moreover, the preservation device according to this seventh embodiment 
enables the cap 78 including the impedance means to be easily attached to 
and removed from the lead storage battery 25 after it has been taken out 
from the housing member 84. This advantageously permits the lead storage 
battery 25 to be again left and preserved for a long period of time. 
The description will then be made of an eighth embodiment of the present 
invention with reference to FIGS. 32-35. 
A chip resistance 88 as an impedance means is directly secured to a lead 
storage battery 87 similar to the lead storage battery 25 in FIG. 5. The 
chip resistance 88 has one end connected to one external terminal 89 of 
the lead storage battery 87 and the other end which is exposed to form an 
exposed portion 90. 
On delivery from the factory, the lead storage battery 87 is housed in a 
covering member 91 of the housing case type to be separable into two 
portions. The covering member 91 has at the upper inner surface thereof a 
printed connection member 92 of an electroconductive pattern film. When 
the lead storage battery 87 is covered with the covering member 91, this 
connection member 92 electrically connects the other end of the chip 
resistance 88 to the other external terminal 93 of the lead storage 
battery 87. 
The lead storage battery 87 manufactured at factory is, after fully 
charged, covered with the covering member 91 to provide 
impedance-connection between the external terminals 89 and 93, through the 
chip resistance 88 and the connection member 92. 
For the use, the removal of the covering member 91 from the lead storage 
battery 87 shuts off the electrical connection between the chip resistance 
88 and the external terminals 89 & 93, permitting the lead storage battery 
87 to be immediately used. 
Even if the covering member 91 is lost, application of an electroconductive 
tape across the chip resistance 88 and the other external terminal 93 may 
easily provide impedance-connection. 
Moreover, the construction of the impedance means attached to the lead 
storage battery itself 87 eliminates the risk to loose the impedance 
means. 
Industrial Utility 
According to the preservation device for lead storage battery of the 
present invention, a retainer-type lead storage battery is preserved with 
an impedance means connected between the external terminals of the lead 
storage battery. This restrains transformation of the PbO.sub.2 corrosion 
layer on the collector member surface into an inactive PbSO.sub.4 layer. 
It is therefore possible to prevent a battery preserved in such 
preservation device from being decreased in capacity without requiring 
troublesome maintenance such as supplementary charging at regular 
intervals, even though it is preserved for a long period of time from its 
forming to the actual use. The present invention thus exhibits a great 
industrial value.