FIELD OF INVENTION
This invention relates to an improved cap for lead acid battery with level indicator. More
particularly. the present invention relates to an improved cap for lead acid battery with
water level indicator which activates a warning buzzer when electrolyte level falls below a
predetermined level.
BACKGROUND PRIOR ART
The most prominent rechargeable, storage battery for ignition and emergency power uses
is the lead-acid battery comprising of a plurality of cells, each containing opposed vertical
lead and lead dioxide electrode plates immersed in aqueous sulfuric acid electrolytc.
During normal use, the water in the electrolyte solution is depleted by the electrolysis that
accompanies the charging process and for other reasons such as charge inefficiencies. In
case too much water evaporates, the electrolyte level recedes past the top of the electrode
plates and the electrode paste can dry, flake off or become irreversibly affected such as by
oxidation of the lead. If too much electrode material flakes off, it can settle at the bottom
and form a bridge short-circuiting cell. A short-circuit of only one cell is sufficient to
render the lead-acid battery useless.
Too much water is also undesirable since that can leak acid onto and behind the battery
casing and as a result corrode the pan below the battery and the fenderwall next to the
battery. It also can cause corrosion of the terminals and cables. Many batteries fail by
corrosion and severing of the terminals from the internal connectors to the cell electrodes.
Now, reference may be made to the following known arts:
US Patent No. 3,891,465 discloses a battery equipped with an indicator for the lowering of
the electrolyte level in the battery. An electrode for detecting the lowering of the level of
the electrolyte is provided on a battery; a circuit for detecting the "on and off' of the
electric current, which is obtained from the battery through said
electrode, is attached to the battery and actuates an alarming device in the circuit when the
level of the electrolyte is lowering below the predetermined level.
Publication No. GB611147 describes a stem carried by a float for indicating the
electrolyte level observed through a glass dome secured to a hollow screw - threaded plug.
The hollow plug with a transparent top, for insertion in the filling opening of the cell to
permit viewing of a float-controlled electrolyte-level indicator arranged to extend into tl~c
hollow plug, and, an absorber mounted in the filling opening below the hollow plug and
about the indicator, for absorbing vapours generated in-the cell, whereby to prevent such
vapours from reaching and depositing on the transparent top of the hollow plug.
US Patent No. 4,981,764 provides an electrolyte level indicator, for use on wet cell
batteries, that may be universally app1ie.d to any battery or group of batteries with a total
voltage of 6 vdc to 48 vdc to monitor the electrolyte level in a single cell. The monitor
includes a battery cap sensor probe that is inserted into a single cell of a wet cell battery
and electrically connected, through a single wire, to a panel mounted transducer that
indicates, by means 'of a flashing LED, that the electrolyte is below an acceptable level
thereby producing a general indication that all the cells in the batterylbatteries should be
filled with water.
US Publication No. 20100019773 describes a battery monitor that can be applied to
existing batteries. The battery monitor may include a probe that can be inserted into a
valve of a battery and a warning indicator for alerting an operator. The warning indicator
may include a buzzer, alarm, or other audible signal, either in addition to a visual indicator
such as an LED or in lieu thereof.
Publication No. GB646260 describes a storage battery plug and liquid level indicator
comprising a vent chamber having top and bottom walls formed with vent openings and
an outer side wall formed to close an opening in a battery cover, a relatively largc,
completely closed and sealed central chamber for lined from transparent material and
having a lower end surface adapted to be submerged in the battery electrolyte and shaped
to reflect upwardly light passing down through the hollow interior of said chamber, said
central chamber extending to the top of said vent chamber and having upper end and lower
end closures, a legend located within the hollow interior of said sealed central chamber on
or above the upper surface of the lower end closure within the central chamber, said
legend being illuminated by light reflected from said lower end surface and being readable
through said upper end closure when the liquid in the battery is below said lower end
surface and being obscured when said lower end surface is submerged in the battery
liquid.
US Patent No:6,653,843 provides an improvement in battery cell monitors in which the
reduction of the level of the electrolyte of a wet cell battery below a predetermined lcvel
may be detected. It does so by placing a metal rod in the electrolyte solution, with the rod
projecting into the battery cell to the minimum desired depth of electrolyte. While in
contact with the electrolyte, current is caused to flow through the rod. When the
electrolyte drops below the predetermined level, the 'contact between the rod and the
electrolyte is lost and the current ceases to flow.
US Patent No. 7,812,613 describes electrolyte levels monitoring in batteries. The
measuring device is located in a batterj and is configured to detect when the electrolyte
level in the battery falls below a particular level. The controller is in electrical
communication with the measuring device. The controller is configured to receivc a signal
from the measuring device indicating when the electrolyte level in the battery has fallen
below the particular level and the controller waits for the wait-period to expire before
enabling an indicator (e.g., an alarm, a light, a message, etc.) to indicate that the battery
should be refilled.
US Patent No. 5,936,382 discloses a device for providing a positive indication that the
minimum acceptable level of electrolyte is present in a battery cell. When the electrolyte
contacts the first terminal a current flows through the circuit causing the LED indicator to
illuminate. As long as the level of the electrolyte remains in contact
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2 3 JAN
with the first terminal, at or above the level, the LED will remain lit. When the level of the
electrolyte drops below the level, contact with the first terminal is broken, and the LED
goes off.
Patent No. 4,587,923 describes battery caps and particularly those which permit the
condition of the electrolyte within the given cell to be determined without relnoval of the
cap.
US Patent No. 4,562,127 provides a battery cap incorporating an indicator for determining
the level of electrolyte in the cell.
US Patent No. 4,978,592 provides a universal electrolyte level indicator which may be
attached to, and made part of, battery powered mobile equipment of all types for the
purposes of providing a warning indication to the operator of the equipment that water
needs to be added to the batteries contained therein.
US Patent No. 6,040,079 describes a battery electrolyte level indicator which can serve as
a replacement for a battery cap and which is highly reliable and efficient in operation.
None of the patents above talks about a provision which can be used for electrolyte/ water
level indication automatically generating an alarm when electrolyte1 water level falls
below predetermined level. Thus, there exists the need of an improved system which
indicates the electrolyte1 water level and generates an audiolvisual buzzer as soon as the
water level falls below the desired level.
In order to overcome the above disadvantages of the prior art, the present invention is
directed to an improved system to act as electrolyte1 water level indicator.
OBJECTS OF THE INVENTION
The primary object of the present invention is to provide an improved cap for lead acid
battery with level indicator to improve battery performance by monitoring the electrolyte/
water level.
Another object of the present invention is to provide an improved cap for lead acid battery
with level indicator which automatically generates an audiolvisual alarm signal when the
electrolyte level is lower than desired level.
Yet another object of the present invention is to provide an improved cap for lead acid
battery with level indicator which operates independently of battery voltage and avoids
degradation of battery plates.
Still another object of the present invention is to provihe an improved cap for lead acid
battery with level indicator which is highly reliable and efficient in operation.
Still another object of the present invention is to provide an improved cap for lead acid
battery with level indicator which is easy to handle and cost effective.
Another object of the present invention is to provide an improved battery cap for
electrolyte1 water level monitoring which can send remote alarm for battery electrolyte
level.
SUMMARY OF THE INVENTION
Accordingly, the present invention provides an improved cap for lead acid battery with
level indicator comprising of a hollow member with a float member slidingly disposed
therein, wherein said float member comprises a float sensing unit for indicating level of
water/electrolyte in the battery cell.
The cap functions as float sensor indicating acid level to help top up the battery when
required. The battery cap of the invention has the provision of a top cap on level indicator
with float at bottom end which engages a stopper to prevent the float member from falling
into the cell and which can close the vent in its highest position.
The cap is provided with the battery in packed form and can be reversed to become a float
sensor thereby helping user know the acid level in use and also to top the battery when
required.
"The controller of the power backup system alerts in form of such as but not limited to the
audio/ video alarm, display indication, SMS, Email, remote data transfer.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Further objects and advantages of this invention will be more apparent from the ensuing
description when read in conjunction with the accompanying drawings and wherein:
Fig. 1 shows: perspective view of cap of the present invention.
Fig. 2 shows: level indicator at different positions i.e. normal water level and low water
level.
2 3 JAN 2011
Fig. 3 shows: level indicator position when water is at desired level and below the desired
level respectively;
Figure 4a shows the single battery arrangement for electrolyte level indication.
Figure 4b shows the single battery and individual cell arrangement for electrolyte level
indication.
Figure 5a shows the multiple battery arrangement for electrolyte level indication.
Figure 5b shows the multiple batteries of the battery bank and individual cell arrangement
for electrolyte level indication.
DETAILED DESCRIPTION OF THE INVENTION WITH REFERENCE '1'0 '1m
ACCOMPANYING DRAWINGS:
The present invention discloses an improved cap for lead acid battery that is inserted into
the cells of a wet cell battery and electrically connected, through a pair of wire to a power
backup system. Said system by means of audiolbuzzer and/or flashing LED, indicates that
the electrolyte is below desired level, thereby alerting the user that the cell(s) in the
batterylbatteries needs to be filled with water. The system improves battery pcrformance
by forwarding low water level signal to UPSIInverter or other system for functioning in
safe mode. Controlled backup system also avoids battery damage.
Now, reference may be made to fig. 1 and fig. 4, wherein said improved cap comprises
two main parts,i.e. a hollow longitudinal member (1) with one end closed and a opaque or
coloured float member (2) slidingly mounted in the cavity of the hollow member, which
moves up and down according to the electrolyte level. The cap also comprises a contact
point (3) which prevents the float member from falling into the cell and is connected to an
audio/visual alarm system of a power backup through a
2 3 .IkN 20"
pair of wires. The battery includes a number ofcells, therefore a number of wires are
merged into a power.backup system having an audiolbuzzer and LED for visual indication
of low water level in the battery.
The longitudinal member of the cap comprises a hollow and transparent tube forming a
cavity. A float preferably of a vivid or opaque color is provided in the cavity. The lcvcl
indicating float member is slidably mounted within the cavity. The float member includes
a float (3) within the lower portion of the cavity and an indicator (4) in the upper portion
of member (1). The indicator is connected to a cap (5) at its upper end which prevents
indicator from falling into the cell. The indicator assumes a visible vertical position within
the cap in relation with the electrolyte/ water level. As the electrolyte level varies, the
position of the indicator correspondingly varies to provide a visual indication of the
electrolyte level in the cell.
A contact point (6) having an inner diameter slightly smaller than the diameter of the cap
is attached to the cavity constituting a stopper so as to prevent the float from falling into
/
the cell.
The cap of the present invention is provided through the main cap (M) of each cell.
Now reference may be made to fig. 2 an'd fig. 3, when the indicator is in the upper portion
of the cap indicating a high electrolyte1 water level. As the electrolyte1 water level in any
of the cells drops, so does the float and the indicator. When the indicator is in the lowcr
portion of the cap, it touches the contact point thereby activating the alarm circuit. As a
result an audiolvideo alarm is triggered indicating that the electrolyte1 water level is low
and addition of electrolyte to the cell is necessary. All the cell of the battery has a pair of
wire1 conductor for electrical connection to detect lower level of electrolyte which is
connected to the signal conditioning unit controlled by the controller of the power backup
system (C) for the alert in form of such as but not limited to the audio/ video alarm,
display indication, SMS, Email.
A panel is provided where all the wires from the cell are connected and the panel is
connected to the supply.
In an embodiment, the electrolyte 'indicator system includes a data acquisition
module such as a wireless transmitter for communicating electrolyte/ water status to a
remote computer. The user is notified of the low electrolyte/ water level using a
computerized notification system such as a phone calling system, text messaging system,
auto email messaging system or any combination thereof through controller and GSM
system in remote locations.
Figure 4a shows the single battery arrangement for eledtrolyte level indicator. The power
backup system is interfaced with single battery to detect the lower level of electrolyte and
raise. the alarm.
Figure 4b shows the single battery and individual cell arrangement for electrolyte level
indicator. The controller of the power backup system is interfaced with individual cells of
the single battery to detect the lower level of electrolyte and raise the alarm wherein the
controller gives visual indication of the electrolyte1 water level
Figure 5a shows the multiple battery arrangement for electrolyte level indicator. The
power backup system is interfaced with multiple batteries to detect the lower level of
electrolyte and raise the alarm.
Figure 5b shows the multiple batteries of the battery bank and individual cell arrangement
for electrolyte level indicator. The controller of the power backup system is interfaced
with individual cells of the multiple batteries to detect the lower level of electrolyte and
raise the alarm wherein the controller gives visual indication of the electrolyte/ water level
2 3 JAN 2014
In an aspect, the cap according to the present invention is provided with the battery as
packed and can be reversed to become a float sensor thereby helping user know the acid
level in use and helps to top the battery when required.
The cap is compatible with all existing batteries and can be provided as an original
equipment cap or can be substituted for the caps of batteries in service. The present
invention controls the evaporation of the water, eliminates the need of topping the water
onto the battery and reduces the water consumption.
The .system can provide audio and visual alarm LEDIdigital indication on vehicle
dashboard.
Reference numerals:-
Fig. 1
TOP Cap (1)
Cap ( 5 )
Level indicator (2)
Indicator (4)
. Contact point (6)
Main cap (M)
Float (3)
Contact point (6)
Fig. 4a
1 SMSIE-mail1Remote Data transfer (S)
Buzzerlaudio (A)
Visual (V)
ControllerIPower backup system (C)
Interface bus to defect lower level of electrolyte (B)
2 3 JAN 201A
Battery (B')
Fig. 4b
SMSIE-maillremote data transfer (S)
Buzzerlaudio (A)
Visual (V) .
Controller with visual indication lower level of electrolyte in individual cell of
batterylpower backup system (C)
Interface Bus to detect lower level of electrolyte in individual cell of battery (B')
SMSIE-maillremote data transfer (S)
BuzzerIAudiq (A)
Visual (V)
Controllerlpower backup system (C)
Interface bus to detect lower level of electrolyte (I)
Batterylbattery bank (BB)
Battery 1 (B1)
Battery 2 (B2)
Battery Nth (Bn)
Fig. 5b
' SMSIE-maillremote date transfer (S)
BuzzerIAudio (A)
Visual (V)
Interface bus to detect lower level of electrolyte (I)
Controllerlpower backup system (E)
2 3 JAN 2O'
Controller with visual indication lower level of electrolyte in individual cell of
battery (Y)
Interface bus to detect lower level of electrolyte in individual cell of battery (X)
BatteryIBattery bank (BB)
Battery 1 (B1)
Battery 2 (B2)
' Battery Nth (Bn)
It is to be noted that the present invention s susceptible to modifications, adaptations and
changes by those skilled in the art. Such variant embodiments employing the concepts and
features of this invention are intended to be within the scope of the present invention,
which is further set forth under the following claims:-

WE CLAIM:

1. An improved cap for lead acid battery with level indicator comprising of a hollow
member with a float member slidingly disposed therein, wherein said float member
comprises a float sensing unit for indicating level of water/electrolyte in the battery
cell.
2. An improved cap as claimed in claim 1, wherein the hollow member is closed at
top and preferably transparent/opaque.
3. An improved cap as claimed in claim 1 or 2, wherein the float member comprising
of a level indicator with a cap at its top end and a float at its bottom end.
4. An improved cap as claimed in any of the preceding claims, wherein the hollow
member is provided with a contact point in proximity to its open end constituting a
stopper so as to prevent the float member from falling into the cell.
5. An improved cap as claimed in any of the preceding claims, wherein the contact
point is connected to audio/video alarm system of power back up for generating an
alarm signal when the electrolyte/water level falls below predetermined level.
6. An improved cap as claimed in any of the preceding claims, wherein the battery
can be signal battery, single battery with individual cell arrangement, multiple
battery, multiple battery with individual cell arrangement.
7. An improved cap as claimed in any of the preceding claims, wherein controller of
the power backup system is interfaced with battery(s) or cells of the battery(s)
through bus to detect lower level of water/electrolyte and raise the alarm.
8. An improved cap as claimed in any of the preceding claims, wherein the indicator
system can include a data acquisition module such as wireless transmitter for
communicating electrolyte/ water status to a remote computer.
9. An improved cap as claimed in claim 8, wherein the user may additionally be
notified using a computerized notification system such as a phone calling system,
text messaging system, auto email messaging system or any combination thereof.
10. An improved cap for lead acid battery with level indicator substantially as herein
described with reference to the accompanying drawings.