Lead-acid rechargeable storage battery

An improvement in lead-acid batteries is disclosed. The improvement is directed toward construction of a lead-acid rechargeable battery in which bipolar positive and negatives plates (biplates) share the same grid or substrate. According to the present invention, such biplates are stacked upon each other, separated by interleaved, highly porous glass mat separators. These substratea positioned between the positive and negative plate areas act as electrical connections attaching the plates to terminals of the battery. The battery case cover is used to provide compressive force on the biplates and separators.

BACKGROUND OF THE INVENTION 
The present invention relates generally to lead-acid rechargeable batteries 
and, in particular, to batteries in which bipolar positive and negative 
plates (biplates) share the same grid or substrate. According to the 
present invention, such biplates and interleaved, highly porous, glass mat 
separators are stacked upon each other in such a manner that the substrate 
positioned between the positive and negative plate areas of the biplates 
act as electrical connections between adjacent stacks. 
Conventional lead-acid batteries are constructed from two volt cells which 
are usually connected in series. This allows these known batteries (whose 
nominal voltage is a multiple of two, or "in parallel") to give increased 
ampere-hour capacity for a combination of series and parallel cells. Each 
cell contains positive and negative plates separated by, in the case of 
"flooded" cells, sheets of porous, low resistance, and oxidation resistant 
materials such as glass, paper, rubber, or polyolefin. In the "flooded" 
cell, the separator exists merely to insulate adjacent positive and 
negative plates from each other while providing a low resistance path 
through which electrons may easily flow. Again, in the flooded cell, free 
electrolyte exists around the plates contained by the walls of the 
(plastic or hard rubber cell) container. 
In cells known as "starved electrolyte" or "sealed recombinant" cells, the 
electrolyte is contained in highly porous, relatively thick glass mats 
interleaved between adjacent positive and negative plates. No "free" 
electrolyte exists in such cells. The electrolyte required to give the 
rated electrical energy output is stored within the pores of the 
separators and the pores of the negative and positive active materials. 
The separate positive and negative plates in conventional lead-acid 
batteries comprise a lead or lead alloy grid, or substrate, into which is 
impressed a paste. Such substrates are manufactured by one of two methods. 
In one such method molten lead or an alloy thereof is poured into a mold 
and frozen. The mold is then opened and the resultant casting is stored 
for between 24 and 48 hours to allow orientation of metallic grain 
structure. In another known method, lead, or lead alloy, sheet is slit and 
expanded to the desired width or length on a continuous basis, and is then 
cut to the desired size. 
SUMMARY OF THE INVENTION 
The choice of lead alloy for use in the positive and, separately, the 
negative grid is of great importance in determining both the operating 
characteristics and life of the battery, under the intended battery 
service conditions. For instance, a combination of positive and negative 
alloys will affect the rate that water is lost from batteries during 
recharge. Further, the positive grid is subjected to varying degrees of 
electro-chemical corrosion, dependent upon the application in which the 
battery is used. This electrochemical corrosion can take the form of a 
corrosion which erodes the positive grid material to a point where the 
grid material is totally eaten away and the grid is no longer capable of 
conducting energy from the plate to the external circuit. A second form of 
corrosion is caused by stress. The formation of certain low density 
compounds of lead tend to stretch the grid resulting, generally, in loss 
of contact between the grid and the impressed active material. In order to 
reduce the effects of this stress, alloy additions such as antimony are 
used to increase the tensile strength of the grid. It is well documented, 
however, that additions of antimony increase the "self discharge" and 
water-loss rates of lead-acid batteries. Those skilled in the art will 
recognize the inherent advantages of a grid material which minimizes water 
loss, has high tensile strength, and possesses a very fine grain 
structure. 
In conventional lead-acid cells, unlike those of a cylindrical nature 
described in U.S. Pat. No. 3,862,861, the positive and negative plates are 
oriented in a vertical plane with the current conducting tab of each grid 
(normally one tab is provided per grid) being positioned at the top of the 
plate. Each of the current conducting tabs of the positive plates within a 
cell are typically connected together by immersing all tabs into a bath of 
molten metal and freezing the metal. The resultant connector piece is 
known as a "cast-on-strap." Similarly, the tabs of all the negative plates 
of the cell are connected during the same operation. 
Because of the need for dissimilar melting temperatures of the tab material 
and the cast-on-strap metal, different alloys of lead are sometimes used 
which creates a potential for corrosion at the junction of the tab and 
cast-on-strap. In as much as there is generally only one conducting tab 
per grid, the efficiency with which electrical energy is conducted from 
the various regions of the plate is far from optimum. Those skilled in the 
art will appreciate the improved conduction efficiency of several 
conducting tabs per plate (as opposed to one), and the elimination of both 
the corrosion potential, and, the reduction of manufacturing costs due to 
the elimination of the cast-on-strap process. 
In the manufacture of a 12 volt battery, six cells must be connected in 
series. This necessitates attaching each of the end cells to the battery 
terminals and five other cell-to-cell connections. The preferred method of 
connecting adjacent cells is by extrusion welding the positive 
cast-on-strap of one cell to the negative cast-on-strap of the adjacent 
cell through a small hole in a plastic partition separating adjacent 
cells. The resultant connection is normally referred to as a 
"through-the-partition" (TTP) connection. Generally, there is only one 
such connection made to connect adjacent cells. The failure of any one of 
these TTP welds will result in an open circuit and render the battery 
useless. It will be recognized that there are significant advantages from 
improved electrical conductivity and reliability of multiple connections 
between adjacent cells, including manufacturing cost reductions, by the 
elimination of the need for TTP connections. 
During the manufacture of conventional lead-acid batteries, the positive 
and negative grids and plates are subjected to a significant amount of 
handling. For example, grids emerging from the casting process are stacked 
and, normally, stored in dedicated areas during the grain orientation 
process. Grids are handled again as they are fed into the pasting process, 
and again as they are stacked as "wet plates" in preparation of the paste 
curing and drying process. The curing and drying process is one in which 
applied paste is changed from a "mud" consistency to one of dry "concrete" 
so that the dried plate is handleable during subsequent processes. Plates 
are again handled during the plate and separator stacking process, and 
again during the cast-on-strap process. Following this latter process, the 
connected groups of plates are normally inserted into the battery 
containers. Those skilled in the art will recognize advantages in reducing 
work-in-process and materials handling requirements; and in the reduction 
in potential for plate damage where the plate and battery design allows 
the plates to be inserted in the container immediately following the 
pasting process. 
The optimum performance and life of lead-acid batteries of the "starved 
electrolyte" or "recombinant" type are dependent upon many factors, 
including applying continuous equal pressure over the whole area of the 
positive and negative plates. Conventional thermoplastic battery 
containers necessarily have a draft angle which allows the male part of 
the injection mold to be withdrawn to enable the container to be ejected 
from the mold. As a consequence, the top of each of the cell compartments 
in, for example, a 12 volt battery container is wider than the bottom of 
the compartment. Those skilled in the art will again recognize the 
advantage of providing equal, controlled, pressure over the whole plate 
area. This is made possible by horizontal orientation of the plates within 
the battery. The controlled pressure being provided by the use of 
non-conducting plastic screeds in each plate, and the sealing of the 
battery cover to the battery container. 
According to the present invention, all stacks of plates share the same 
environment such that a novel recombinant battery is provided . U.S. Pat. 
No. 3,862,861 discloses an early design of a recombinant-type cell in 
which lead based grids of greater than 99.9% purity (by weight, and 
thereby having a high hydrogen "over-potential") are pasted and assembled 
into cells which are tightly contained by a cell container and cover. U.S. 
Pat. No. 4,166,155 addresses the need for differing lead alloys in the 
positive and negative grids to achieve a maintenance free, lead-acid 
battery wherein the tensile strength of the positive grid is increased by 
the additions of antimony and cadmium, while limiting the gas evolution 
associated with constant voltage overcharge. 
Several other patents address the use of biplates in the construction of 
lead-acid batteries. For instance, U.S. Pat. No. 4,275,130 discloses a 
battery in which the electrodes take the form of parallel, stacked 
biplates composed of a thermoplastic material (such as polypropylene) with 
conductive fibers of carbon or metal embedded in it to strengthen 
conducting elements. Each biplate is provided with parallel strips of lead 
in electrical contact with the conductive fibers to serve as a grid. The 
active material is held between thin, porous glass mats; and the stacked 
assembly is then axially compressed and assembled into the battery case. 
In consideration of the advantages provided by increased electrical 
performance; reductions in battery manufacturing costs, work-in-process 
inventory (and thereby working capital requirements), manufacturing 
process time; and the elimination of certain processes known to cause 
premature service failure, it is a further object of the invention to 
provide a substrate for use in a lead-acid battery biplate, manufactured 
from one continuous length or several separate lengths of coextruded wire, 
as described in U.S. Pat. No. 4,658,623 (hereby incorporated by 
reference). 
It is yet another object of the invention to incorporate in the substrate 
strips corrosion resistant, lightweight, thermoplastic or similar material 
to locate and retain the wires in the substrate, and to accurately 
position the plate in the battery container. 
It is still another object of this invention to provide a means of 
utilizing the common grid framework to facilitate intercell connections. 
It is yet another object of this invention to use the previously mentioned 
plastic screeds in the grid structure to equalize the axial pressure among 
each stack of plates when the plates are lying in a horizontal plane, 
thereby eliminating increased pressure on the plates, toward the bottom of 
the stack, due to the weight of the plates above them. 
It is another object of the invention to so arrange the stack of biplates 
in a 12 volt battery (or battery of greater voltage) in such a manner that 
the battery container partitions and walls maintain the optimum axial 
pressure on the assembled stacks. 
Finally, it is yet another object of this invention to construct a 
recombinant lead-acid battery using the aforesaid biplates.

DETAILED DESCRIPTION OF THE INVENTION 
Throughout this disclosure, the term "wire" shall refer to a coextruded, 
coaxial wire as described in detail in U.S. Pat. No. 4,658,623 
(incorporated herein by reference). The term "core material" as used 
throughout the specifications shall refer to fibrous, high tensile 
strength, non-conducting materials such as glass fiber yarn, Kevlar, or 
highly conductive, relatively high tensile strength metals such as 
aluminum and copper. The term "sheath" shall refer to the annulus of lead 
material surrounding the core, such lead to be pure lead (of 99.99% purity 
or better) or any alloy of lead. The term "biplate" shall mean a combined 
positive and negative plate sharing the same substrate, the portion of the 
biplate which has been pasted with positive active material being 
separated from the portion of the plate pasted with negative active 
material by an unpasted area of the grid. 
The method of coextruding a lead sheath over a core material and the 
coaxial wire derived therefrom (as described in U.S. Pat. No. 4,658,623) 
offers the opportunity to use a pure lead or lead alloy material whose 
tensile strength is artificially increased by the use of a high tensile 
strength core (such as glass fiber yarn), whose conductivity can be 
significantly increased (by using a copper or aluminum wire as the core 
material). 
The grain size of extruded lead has been documented as much finer than that 
of cast or wrought lead, particularly if quenching occurs very soon after 
extrusion. Increased tensile strength will be beneficial in retarding the 
well known growth of positive grids in lead-acid batteries. Small grain 
size will retard the effects of weight loss corrosion due to anodic 
attack. 
Reference will now be made to the drawings. FIG. 1 shows a preferred 
embodiment of a grid for use in a biplate comprising several parallel 
strands 1 of coextruded wire. The plastic strips 2 (hereafter referred to 
as screeds) running perpendicular to the wire strands may be injection 
molded around the wires such that the manufacture of such grids could be 
done on a continuous basis. The grids could then be cut to the desired 
length and/or width. The width of the screeds will extend out beyond the 
outer wires on both sides of the grid for reasons referred to later. 
FIG. 2 shows a grid for a biplate made by weaving wires on conventional 
wire weaving equipment. 
FIG. 3 shows the biplate having had positive 3 and negative active 
materials 4 impressed into the grid. Single positive and negative plates 
("end-plates") as shown in FIG. 4 will be required for the terminal stacks 
of the batteries of this invention. Such end-plates can be made by 
severing the wires 1 of the biplate (as shown in FIG. 3) at the mid-point 
of the biplate. 
The manufacture of conventional plates for lead-acid batteries involves 
impressing positive and negative pastes onto separate grids, and 
thereafter subjecting such plates to a separate curing and drying process. 
This curing and drying process may involve loading the freshly pasted 
plates into an atmosphere with controlled humidity and temperature for a 
period of hours, sometimes as much as 48 hours. This process is deemed 
necessary: to allow the ingredients of the paste mix, one of which is 
usually sulfuric acid, to interact to produce desired amounts of lead 
oxides and lead sulfate; to reduce the free lead content of the oxide used 
in the paste to a low level (normally below 5% of the dry plate weight); 
and to reduce the moisture content of the dried plate to below (typically) 
2%. 
According to the invention, plates which have been freshly pasted with a 
paste containing no sulfuric acid ingredient are placed immediately into 
the container and are interleaved with separators (in the manner described 
below) which have been fully saturated with dilute sulfuric acid whose 
concentration is higher than 30% by weight. In this manner, the process of 
curing and drying can be avoided. 
Next, I will describe assembly of a battery for conditions: (i) where the 
plates have been cured and dried along conventional lines and the 
separators used in the assembly process are dry; (ii) where the plates 
have been cured and dried along conventional lines and the separators have 
been fully saturated with dilute solution of sulfuric acid with a 
concentration of 30% or greater by weight; (iii) where freshly pasted 
plates are interleaved with dry separators; and (iv) where freshly pasted 
plates are interleaved with separators which have been fully saturated 
with a dilute solution of sulfuric acid with a concentration of 30% or 
greater by weight. 
FIG. 5 shows stacking of the biplates 5 and positive 6 and negative 7 
end-plates into a container 8 to form the basis of a 12 volt battery. The 
first layer of plates 9 incorporates a positive end-plate, two biplates, 
and an end negative plate positioned on the base of the container. The 
wires 10, protruding from the end-plates 6 and 7, point outward and toward 
the open area of the container. These plates and successive layers of 
separators and plates may be positioned manually or automatically into the 
container immediately after the pasting process. 
Pieces of highly porous glass mat separators 11 of the required area and 
thickness to contain sufficient electrolyte in the pores thereof are then 
positioned on top of each of the plates in this first layer. The 
dimensions of the separator pieces must be such that there is adequate 
overlap beyond the edges of the plate to ensure adequate protection 
against short circuits between adjacent positive and negative plates. 
There are known formulae enabling the battery designer to calculate the 
required volume of glass mat separator to provide sufficient electrolyte 
for a desired coulombic output of a battery. 
The second layer of plates 12, consisting of three biplates, is then laid 
upon the separators in such a fashion that each part of the biplate of 
this second layer is of opposite polarity to the end-plate or part of the 
biplate directly underneath it in the first layer. 
Another layer of glass mats 11 is placed upon the second layer of plates. A 
third layer of plates 13, comprising positive end-plate, two biplates and 
negative end-plate, is then laid upon the separators in the same 
arrangement as the first layer of plates. A layer of glass mat separators 
is laid upon the third layer of plates. A fourth layer of plates 14, 
consisting of three biplates, is laid upon the separators in the same 
arrangement as the second layer of plates. 
This sequence of alternating layers of plate and separators is continued 
until the stack contains the required number of plates for the desired 
coulombic output of the battery. The desired electrical energy can be 
calculated by those skilled in the art, and will depend upon such factors 
as the weight and density of positive and negative active materials; the 
area and thickness of the plates; the area, thickness, eventual 
compression and porosity of the glass mat separators; the concentration of 
the sulfuric acid used during filling; and more. 
Those skilled in the art of lead-acid battery design will also be capable 
of calculating the required matrix of such factors for a desired 
electrical energy and power output. 
FIGS. 6 and 7 show other possible layouts of the stacks of plates using the 
concept described above. It is shown in FIG. 8 (using the layout of FIG. 5 
as an example) the path of electrons during a discharge of a battery so 
constructed is from an external electrical circuit into the wires 10 of 
the positive end-plates 6; thence into the positive active material of the 
end-plate; vertically up and/or down through the electrolyte contained in 
the interleaved separator into the active material and grid of the 
adjacent negative plates; through the interstack connector wires in the 
unpasted portion of the biplate to the positive plate of the biplate; up 
and/or down through electrolyte contained in the interleaved separator 
into the active material and grid of the adjacent negative plate; through 
the interstack connector wires in the unpasted part of the biplate into 
the grid and active material part of the positive plate of the biplate and 
so on to the wires of the negative end-plate and out into the external 
electrical circuit. 
The electron path for a battery containing only plate layers 9 and 12 is 
shown in FIG. 8 by the sequence path A through R. In effect, it is shown 
that the wires in the center of the biplate perform the same functions as 
the cast-on-strap and TTP weld found in conventional batteries. 
FIG. 9 shows a plan view of the first layer of plates in FIG. 5. The 
integrally molded ribs 15 and partitions 16 of the container 8 combine 
with extensions of the plastic screeds 2 (beyond the active material 
width) to provide a means of locating the biplates in the container. Such 
an arrangement is a preferred embodiment of this invention. 
When the required number of plates and separators have been stacked, the 
battery cover 17 shown in FIG. 10, is then forced down onto the stacks of 
plates until the edges of the cover 18 mate with the upper faces of the 
container walls and partitions 19. The amount of pressure required to 
compress the stack to the required thickness will be typically 5 to 7.5 
pounds per square inch of plate surface. As an example, if the length and 
width of the pasted area of the one part (either positive or negative) of 
the biplate are 3 inches and 3 inches respectively, then the arrangement 
of a 12 volt battery shown in FIG. 5 will require between 
9.times.5.times.6 (=270 pounds) and 9.times.7.5.times.6 (=405 pounds) of 
force to compress the stack to the required height. As the faces of the 
cover and container mate, they are bonded together by pre-applied 
adhesive, or by welding the two surfaces together by heat or ultrasonic 
means. 
The end wires 10 protruding from the positive 6 and negative 7 end-plates 
are then resistance welded to the terminal wires 20 as shown in FIGS. 11 
and 12. The terminal wires may be coextruded containing a highly 
conductive core such as copper or aluminum. The sheath material of the 
terminal wires can be similar to that of the end wires. Next, the terminal 
wires are resistance welded to the positive terminal block and negative 
terminal block 21, such blocks being integral parts of the terminals 22. 
Container side pieces 23 are thereafter affixed to the container 8 and 
cover 17 by heat sealing, ultrasonic or other means (FIG. 13). 
Further processing of the battery will depend on the methods employed in 
the previous assembly. If the stacks were assembled using dried plates and 
dry separators, or wet plates and dry separators, then the container must 
be turned through 90.degree. such that the plates are in a vertical plane. 
Dilute sulfuric acid of a concentration between 30% and 50% is fed into 
the container through tubes introduced through holes 24 in the container 
side (FIG. 14). The rate of acid addition must be controlled to ensure 
complete expulsion of the air from the pores of the plates and separators. 
This rate will depend upon the compression which has been exerted on the 
separators by the mating of the container and cover. When the battery is 
completely flooded, the tubes must be extracted and the battery should 
immediately be inverted to allow the acid to drain into a sump through the 
holes 24. The battery should then be connected to a suitable D.C. power 
supply to allow electrochemical formation of the plates. During the 
formation process, the plates should be maintained in a vertical position. 
If both plates and separators were assembled in a dry condition, then the 
battery may be removed for storage in inventory until such time the 
filling and formation process can be undertaken. 
If the separators were stacked in a fully saturated condition, the battery 
should be put on formation immediately following the point at which the 
container side pieces were affixed to the container. 
Following formation, the holes (FIG. 15) are then plugged with pressure 
relief valves 25 designed to relieve excessive gas at a pressure above, 
typically, 2.5 p.s.i. 
Batteries of the subject invention were built using various design, 
assembly, and process techniques and subsequently tested. The methods of 
Battery assembly and subsequent electrical test results achieved are 
tabulated in Table 1. 
Various modifications and improvements may be made to the disclosed 
embodiments of the invention without departing from the overall scope and 
spirit of the invention. For example, different paste compositions may be 
used to form the biplates, or various biplate orientation and stacking, 
configurations may be used to create a lead-acid battery according to the 
present invention. 
TABLE 1 
__________________________________________________________________________ 
DESIGN AND PERFORMANCE CHARACTERISTICS OF 
BATTERIES OF THIS INVENTION. 
__________________________________________________________________________ 
SERIAL NO. 4J 10E 
BATTERY VOLTAGE 4 4 
NO. OF LAYERS OF BIPLATES 
10 6 
AREA OF EACH PLATE 3" .times. 3.25" 3" .times. 3.25" 
GRID ALLOY 99.98% Pb 99.98% Pb 
GRID DESIGN WOVEN MESH, 8 WEAVES PER 
11 ALLEL WIRES (FIG. 1) 
INCH (FIG. 2). 
.060" OUTSIDE DIA., .013" GLASS 
.050" OUTSIDE DIA., .013" 
GLASS 
FIBER CORE. FIBER CORE. 
WEIGHT OF BIPLATE GRID: 123 g. 
WEIGHT OF BIPLATE GRID: 32 g. 
POSITIVE ACTIVE MATERIAL 
NON-SULFATED PASTE, 73.34 g/in.sup.3 
NON-SULFATED PASTE, 60.87 
g/in.sup.3 
WET DENSITY, 50 g WET PASTE 
WET DENSITY, 43 g WET PASTE 
WEIGHT PER PLATE. NO CURING/ 
WEIGHT PER PLATE. NO 
DRYING. CURING/DRYING. 
NEGATIVE ACTIVE MATERIAL 
NON-SULFATED PASTE, 76.9 g/in.sup.3 
NON-SULFATED PASTE, 70.84 
g/in.sup.3 
WET DENSITY. 50 g WET PASTE 
WET DENSITY. 43 g WET PASTE 
WEIGHT PER PLATE. WEIGHT PER PLATE. 
NO CURING/DRYING NO CURING/DRYING 
SEATOR 2 PIECES EACH 3.25" .times. 3.25" .times. 
1 PIECES EACH 3.25" .times. 
3.25" .times. 
.050" THICK BEFORE .075" THICK BEFORE 
COMPRESSION. 
COMPRESSION. DEXTER TYPE 
EVANE TYPE AGM 
APPX .040" (EACH) APPX .060" (EACH) AFTER 
AFTER COMPRESSION. COMPRESSION. 
FILLING MATERIAL SEATORS PRE-SOAKED IN 
SEATORS ASSEMBLED DRY. 
1.150 sg E.sub.2 SO.sub.4. BATTERY 
BATTERY SOAKED IN 1.350 sg 
SOAKED IN 1.300 sg H.sub.2 SO.sub.4 
H.sub.2 SO.sub.4 FOR 1 HOUR 
AFTER 
1 HOUR AFTER ASSEMBLY. 
ASSEMBLY. 
FORMATION 10 AMPS FOR 6 HOURS, 
1.2 AMPS FOR 36 HOURS 
5 AMPS FOR 14.4 HOURS. 
FOLLOWED BY 0.3 AMPS 
FOR 12 HOURS. 
DISCHARGE NO. 
RECHARGE NO. 
1 33.4 MINS @ 5.6 A TO 3.50 VOLTS 
86 MINS @ 2.58 A TO 3.50 VOLTS 
1 0.5 A FOR 28 HOURS 1.2 A FOR 4 HOURS, 0.2 A FOR 8 
HOURS 
2 35.4 MINS @ 5.6 A TO 3.50 VOLTS 
101 MINS @ 2.61 A TO 3.50 
VOLTS 
2 CONSTANT POTENTIAL AT 2.50 vpc 
CONSTANT POTENTIAL AT 2.70 vpc 
3 47.7 MINS @ 5.6 A TO 3.50 VOLTS 
105 MINS @ 2.59 A TO 3.50 
VOLTS 
3 CONSTANT POTENTIAL AT 2.45 vpc 
CONSTANT POTENTIAL AT 2.70 vpc 
4 115.6 MINS @ 5.6 A TO 3.50 VOLTS 
106 MINS @ 2.63 A TO 3.50 
VOLTS 
4 CONSTANT POTENTIAL AT 2.45 vpc 
CONSTANT POTENTIAL AT 2.70 vpc 
5 114.0 MINS @ 5.6 A TO 3.50 VOLTS 
109 MINS @ 2.64 A TO 3.50 
VOLTS 
10 125 MINS @ 5.6 A TO 3.50 VOLTS 
124 MINS @ 2.52 A TO 3.50 
VOLTS 
15 150.5 MINS @ 5.0 A TO 3.50 VOLTS 
126 MINS @ 2.60 A TO 3.50 
VOLTS 
17 189.2 MINS @ 4.22 A TO 3.50 VOLTS 
129 MINS @ 2.61 A TO 3.50 
VOLTS 
25 126 MINS @ 5.6 A TO 3.50 VOLTS 
130 MINS @ 2.64 A TO 3.50 
VOLTS 
35 102 MINS @ 5.6 A TO 3.50 VOLTS 
117 MINS @ 2.60 A TO 3.50 
VOLTS 
BATTERY DISMANTLED AFTER 
BATTERY CYCLING PAST 
37 CYCLES 41 CYCLES 
11A 12D 
4 4 
6 6 
3" .times. 3.25" 3" .times. 3.25" 
Pb/.60% Sn Pb/.1% Sb 
11 ALLEL WIRES (FIG. 1) 
11 ALLEL WIRES (FIG. 1) 
.050" OUTSIDE DIA., .013" GLASS 
.050" OUTSIDE DIA., .013" 
GLASS 
FIBER CORE WEIGHT OF 
FIBER CORE WEIGHT OF 
BIPLATE GRID: 32 g BIPLATE GRID: 32 g 
NON-SULFATED PASTE, 60.87 g/in.sup.3 
NON-SULFATED PASTE, 60.87 
g/in.sup.3 
WET DENSITY, 43 g WET PASTE 
WET DENSITY, 43 g WET PASTE 
WEIGHT PER PLATE. NO CURING/ 
WEIGHT PER PLATE. NO CURING/ 
DRYING. DRYING. 
NON-SULFATED PASTE, 70.84 g/in.sup.3 
NON-SULFATED PASTE, 70.84 
g/in.sup.3 
WET DENSITY. 43 g WET PASTE 
WET DENSITY. 43 g WET PASTE 
WEIGHT PER PLATE. NO 
WEIGHT PER PLATE. NO 
CURING/DRYING. CURING/DRYING. 
1 PIECES EACH 3.25" .times. 3.25" .times. 
1 PIECES EACH 3.25" .times. 
3.25" .times. 
.075" THICK BEFORE .075" THICK BEFORE 
COMPRESSION. EVANE TYPE AGM 
COMPRESSION. EVANE TYPE AGM 
APPX .046" (EACH) AFTER 
APPX .060" (EACH) AFTER 
COMPRESSION. COMPRESSION. 
SEATORS ASSEMBLED DRY. 
SEATORS ASSEMBLED DRY. 
BATTERY SOAKED IN 1.350 sg 
BATTERY SOAKED IN 1.350 sg 
E.sub.2 SO.sub.4 FOR 1 HOUR AFTER 
H.sub.2 SO.sub.4 FOR 1 HOUR 
AFTER 
ASSEMBLY. ASSEMBLY. 
1.2 AMPS FOR 36 HOURS FOLLOW- 
1.2 AMPS FOR 36 HOURS FOLLOW- 
ED BY 0.3 AMPS FOR 12 HOURS. 
ED BY 0.3 AMPS FOR 12 HOURS. 
88 MINS @ 2.56 A TO 3.50 VOLTS 
67 MINS @ 2.60 A TO 3.50 VOLTS 
1.2 A FOR 4 HOURS, 0.2 A FOR 8 
1.2 A FOR 4 HOURS, 0.2 A FOR 8 
HOURS HOURS 
100 MINS @ 2.60 A TO 3.50 VOLTS 
92 MINS @ 2.60 A TO 3.50 VOLTS 
CONSTANT POTENTIAL AT 2.70 vpc 
CONSTANT POTENTIAL AT 2.90 vpc 
104 MINS @ 2.57 A TO 3.50 VOLTS 
102 MINS @ 2.60 A TO 3.50 
VOLTS 
CONSTANT POTENTIAL AT 2.70 vpc 
CONSTANT POTENTIAL AT 2.90 vpc 
108 MINS @ 2.57 A TO 3.50 VOLTS 
108 MINS @ 2.61 A TO 3.50 
VOLTS 
CONSTANT POTENTIAL AT 2.70 vpc 
CONSTANT POTENTIAL AT 2.90 vpc 
113 MINS @ 2.54 A TO 3.50 VOLTS 
113 MINS @ 2.60 A TO 3.50 
VOLTS 
121 MINS @ 2.60 A TO 3.50 VOLTS 
124 MINS @ 2.61 A TO 3.50 
VOLTS 
128 MINS @ 2.60 A TO 3.50 VOLTS 
114 MINS @ 2.62 A TO 3.50 
VOLTS 
128 MINS @ 2.63 A TO 3.50 VOLTS 
131 MINS @ 2.62 A TO 3.50 
VOLTS 
127 MINS @ 2.59 A TO 3.50 VOLTS 
BATTERY DISMANTLED AFTER 21 
81 MINS @ 2.60 A TO 3.50 VOLTS 
CYCLES 
BATTERY CYCLING PAST 41 
CYCLES 
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