Claims:1) A lead acid battery comprising one or more cells including a positive electrode, and a negative electrode disposed in an electrolyte material being characterized by the electrolyte material having an electrolyte specific gravity value between 1.15 - 1.25.
2) The lead acid battery as claimed in claim 1, wherein an electrolyte composition of the electrolyte material comprises 20-25% acid by weight and 80-75% water by weight.
3) A lead acid battery comprising one or more cells including a positive electrode, and a negative electrode disposed in an electrolyte material, characterized in that;
the negative electrode comprising high surface area carbon additive material; and
the electrolyte material is configured with an electrolyte of specific gravity value between 1.15 – 1.25.
4) The lead acid battery, as claimed in claim 3, wherein an electrolyte composition of the electrolyte material comprises 20-25% acid by weight and 80-75% water by weight.
5) A battery charging system to charge a lead acid battery, the system to charge the lead acid battery is characterized by a fast charging time duration to charge the lead acid battery; the system comprising:
the lead acid battery comprising one or more cells including a positive electrode and a negative electrode disposed in an electrolyte material having an electrolyte specific gravity value between 1.15 to 1.25;
a charging unit connected to the lead acid battery; the charging unit being adapted to facilitate power supply to charge the lead acid battery;
a control unit communicatively connected to the charging unit, the control unit being adapted to control the power supply to the lead acid battery through the charging unit to charge the lead acid battery; and
a power source connected to the charging unit and the control unit, the power source being adapted to supply power to the charging unit and the control unit.
6) The battery charging system as claimed in claim 5, wherein the control unit being adapted to increase the power supply in consecutive charging cycles.
7) The battery charging system as claimed in claim 6, wherein increase in the power supply in consecutive charging cycles is defined up to a 105-110 % increase in the power supply with respect to the power supply in a previous charging cycle through the charging unit to the lead acid battery.
8) The battery charging system as claimed in claim 5, wherein the negative electrode of the lead acid battery comprising high surface area carbon additive material.
9) The battery charging system as claimed in claim 5, wherein the electrolyte composition includes 20-25% acid by weight and 75-80% water by weight.
10) A method to charge the lead acid battery with a charging system which is characterized by a fast charging time duration to full charge the lead acid battery, where the lead acid battery comprises one or more cells including a positive electrode and a negative electrode comprising high surface area carbon additive material, the positive electrode and the negative electrode being disposed in an electrolyte material having an electrolyte specific gravity value between 1.15 to 1.25, the method includes;
providing the power supply to the lead acid battery using a charging unit connected to a power source; and
increasing the power supply to the lead acid battery through the charging unit up to 105-110% in consecutive charging cycles using a control unit
, Description:TECHNICAL FIELD
[0001] The present subject matter, in general, relates to a lead acid battery, in particular relates to a lead acid battery that can be charged to full capacity in a faster time duration using a system and method for same.
BACKGROUND
[0002] With increasing environment related concerns and with limited resources of natural petroleum, across industrial and non-industrial applications, fuel cells are considered substitute for source of energy. A lead acid battery is made of a number of cells acting as a energy device. The lead acid battery is inexpensive compared to other available options therefore is preferable in automotive industry especially in two and three-wheeler industry.
[0003] Said lead acid batteries are rechargeable and can be supplied with current for a predetermined time to charge the battery. Normally lead acid battery, cannot accept high current for quickly charging the battery to its full capacity. When the lead acid batteries are charged at a higher current, it does not get charged to its full capacity & delivers poor capacity. Also, further fast recharge cycles may lead to further deterioration of capacity and finally may damage the battery leading to poor durability.
[0004] Generally, utility vehicles (two, three and four wheelers) are provided with the high capacity lead acid batteries only for Start, Light and Ignition (SLI) applications. As explained above said lead acid batteries has poor durability and require longer time to charge the vehicle, which is not preferable to the user. Also, the capacity of the battery is not fully utilized as the battery required only for selective operations. In addition, frequent replacement of these batteries may incur high cost to the user of these vehicles. As for practical usage, slow charging of the battery is not preferable, hence a system is required in which the lead acid battery can be charged faster to its full capacity while maintaining better efficiency and life of battery.

BRIEF DESCRIPTION OF THE DRAWINGS
[0005] The detailed description is provided with reference to the accompanying figures. The same reference numbers are used throughout the drawings to denote like features and components.
[0006] Fig. 1 illustrates a lead acid battery in accordance with an embodiment of the present invention.
[0007] Fig. 2 illustrates a system to charge the lead acid battery in accordance with an embodiment of the present invention.
[0008] Fig. 3 depicts a graph showing the capacity vs charging cycles analysis of the lead acid battery (an embodiment of the present invention) with respect to the lead acid battery as used in existing technology (prior art).
DETAILED DESCRIPTION
[0009] It is an objective of the present invention is to provide a lead acid battery that includes a positive electrode and a negative electrode disposed in an electrolyte material. Said electrolyte material as per the present invention has a specific electrolyte composition of 20-25% acid by weight and 80-75% water by weight. Said electrolyte material includes an electrolyte specific gravity value between 1.15 - 1.25. The negative electrode is made of high surface area carbon additive material. In a preferred embodiment, the high surface area carbon additive material includes multi-wall carbon nanotube particles.
[00010] It is another objective of the present invention to provide a system to charge said lead acid battery such that it has fast charging time duration to fully charge said lead acid battery. The system includes the lead acid battery that includes the positive electrode and the negative electrode disposed in the electrolyte material having the electrolyte specific gravity value between 1.15 - 1.25. The system also includes a charging unit, a control unit, and a power source. The charging unit is connected to the lead acid battery; the charging unit being adapted to facilitate power supply to the lead acid battery. The control unit is communicatively connected to the charging unit and is being adapted to control the power supply to the lead acid battery through the charging unit to charge the lead acid battery. The power source is connected to the charging unit and the control unit, and is being adapted to supply power to the charging unit and the control unit.
[00011] It is another objective of the invention to provide the system as well as a method to charge said lead acid battery. In said system and method, the control unit is adapted to increase the power supply in consecutive charging cycles. Said increase in the power supply in consecutive charging cycles is defined by upto 105-110 % increase in the power supply to the lead acid battery with respect to the power supply in a known charging cycle through the charging unit to the lead acid battery.
[00012] The advantages of the present subject matter would be described in greater detail in conjunction with one or more embodiments with the corresponding figures in the following description. As shown in Fig. 1, lead acid battery (100) includes a plurality of cells having a positive electrode (101), a negative electrode 102, an electrolyte material 103, and a container 104. The positive electrode 101 and the negative electrode 102 are disposed in the electrolyte material 103, which is stored in the container 104. The container 104 is sealed such that upper end (101u, 102u) of each of the positive electrode (101) and the negative electrode 102 is connected to an exposed conducting channel 106through said sealing, for connecting the lead acid battery 100 to the load for supplying power or input source for charging the lead acid battery 100.
[00013] Generally, the positive electrode 101 is made of a paste coated over a lead alloy grid. The paste for the positive electrode 101 contains grey oxide, carbon black, dynel fibre, sulphuric acid and water. The paste for the positive electrode 101 is prepared by mixing of commercial grey oxide while mixing required quantity of carbon black, dynel fibre added. Mixing of this powder material continuously to certain time. For making paste like material purpose required quantity of water and specified gravity of sulphuric acid added. Mixing process continues until paste should be maintained above 40°C. In an embodiment, the positive electrode 101 may include a combination of multiple plates prepared as mentioned above.
[00014] Similarly, in general prior art practice, the negative electrode 102 is made of a paste coated over a lead alloy grid in which the paste contains grey oxide, carbon, barium sulphate, lignin, sulphuric acid and water. The negative electrode 102 contains effective amount of water with sulphuric acid. The paste for the negative electrode is prepared by mixing of commercial grey oxide while mixing required quantity of carbon, barium sulphate, lignin added. This power material is mixed for a certain time for making paste by adding required quantity of water and specified gravity of sulphuric acid. Mixing process is continued at a temperature maintained above 40°C until paste is formed.
[00015] As per an embodiment of the present invention, the paste of the negative electrode 102 is provided with the high surface area carbon additive material (105) in addition to the grey oxide, carbon, barium sulphate, lignin, sulphuric acid, and water. Addition of high surface area carbon additive material (105) enhances the capacity of the negative electrode (102), and provide most available active material for utilization thereby increasing the capacity of the lead acid battery (100). In a preferred embodiment, the high surface area carbon additive material (105) includes multi-wall carbon nanotube particles.
[00016] The positive electrode 101 and the negative electrode 102 are disposed in the electrolyte material 103 that is stored in the container 104. As per an embodiment of the present invention, the electrolyte composition of the electrolyte material (103) comprises 20-25% acid by weight and 80-75% water by weight such that the specific gravity value of between 1.15 – 1.25. In a preferred embodiment, sulphuric acid is used in the electrolyte material, however any other suitable acid base may be used for the electrolyte material.
[00017] Cells prepared as described above method are assembled to get the lead acid battery (100) of desired output. For example, in a preferred embodiment mentioned cells are assembled to form a 12 V battery for a required capacity of SLI (starting, lighting, ignition) application of the vehicle. In the present embodiment, the battery 100 is described with single cell structure, however in order to achieve higher efficiency lead acid battery, multiple cells may be assembled and disposed in the container 104.
[00018] Referring to Fig. 2, the lead acid battery 100 is efficiently charged using a system 200 that includes lead acid battery 100, a charging unit 201, a control unit 202, and a power source 203.
[00019] The charging unit 201 is connected to the lead acid battery 100. The charging unit 201 facilitates power supply to the lead acid battery 100 for charging.
[00020] The control unit 202 is communicatively connected to the charging unit 201, such that the control unit 202 controls the power supply to the lead acid battery 100 through the charging unit 202 to charge the lead acid battery 100. The control unit 202 is being adapted to increase the power supply in consecutive charging cycles. Increase in the power supply in consecutive charging cycles is defined by up to 105-110 % increase with respect to the power supply in a previous charging cycle through the charging unit 201 to the lead acid battery 100.
[00021] The power source 203 is connected to the charging unit 201 and the control unit 202 to supply power to the charging unit 201 to charge the lead acid battery 100 and for its function and to the control unit 202 for its function.
[00022] As an objective of the present invention, in operation the system to charge the lead acid battery 100 is characterized by a fast charging time duration to fully charge the lead acid battery 100. With a higher current acceptance due to diluted electrolyte material, the lead acid battery 100 can be charged faster to its full capacity. In addition, with the negative electrode 102 comprising high surface area carbon additive material 105, output capacity of the lead acid battery 100 is also increased. To charge said battery 100, the power supply is provided to the lead acid battery 100 through the charging unit 201. The charging unit 201 is connected to the power source 203 to receive the required power to function and to transfer required regulated power to the battery 100. The charging unit 201 is connected to the control unit 202 that regulates the power supply that is being sent to the lead acid battery 100. In an embodiment, the control unit 202 is adapted increase the power supply to the lead acid battery 100 in consecutive cycles up to 105-110 % in order to charge the lead acid battery 100 faster and up to its full capacity. While charging and discharging the lead acid battery 100 with diluted electrolyte material (low specific gravity), intermolecular movement is higher therefore for every next charging cycle an increased power supply is required to get the lead acid battery 100 charged to its full capacity. The lead acid battery 100 as described above is charged with a system and method as mentioned, the full charging capacity of the lead acid battery 100 can be achieved faster and also the capacity, efficiency and life of the lead acid battery 100 will be increased as it will sustain a high number of discharge cycles with same efficiency, in comparison with the lead acid batteries existing in prior art.
[00023] Referring to Fig. 3, an exemplary testing embodiment is shown. Three lead acid batteries are provided with various specific gravity of electrolyte material (sulphuric acid with 1.17, 1.18 (in accordance with the present invention), and 1.26 (diluted as per technology known in prior art). Said lead acid batteries, having specific gravity 1.17 and 1.18 are analyzed for fast charging and discharging profile with continuous cycles over their capacity deliverability with 14 V to 17 V supply standard.
[00024] Fig. 3 shows the capacity variation during charge-discharge cycle based on specific gravity. As shown in the graph, the lead acid battery with the specific gravity 1.26 (non-diluted- as per technology known in prior art), the capacity starts decreasing after few initial cycles thereby decreasing the efficiency and life of the battery.
[00025] Whereas, for lead acid battery 100, prepared in accordance to the present invention, provided with specific gravities of 1.17 and 1.18 (diluted), remains almost constant through all charging and discharging cycles, resulting in a longer life of the lead acid battery.
[00026] Fig 3 depicts that overall capacity of the lead acid battery having lower specific gravity of the electrolyte material (1.17 & 1.18) is (1.2 Ah & 1.4Ah) which is lesser than the overall capacity 2.0 Ah of the known lead acid batteries with high specific gravity electrolyte material (1.26 or more used in prior art). For example, as shown in the figure 3, in a positive cycle, capacity of non-diluted battery with specific gravity 1.26 is remains between 1.5 Ah to 2.2. Ah, and the capacity of diluted battery having specific gravity 1.17 remains between 1.1 Ah to 1.2 Ah. Similarly, in a negative cycle, capacity of non-diluted battery with specific gravity 1.26 is remains between -1.4 Ah to -2Ah and the capacity of diluted battery having specific gravity 1.17 remains between -1 Ah to -1.2 Ah. Therefore, it is clearly evident that the diluted lead acid batteries are more stable and can last longer than the non-diluted lead acid batteries. Life expectancy and sustainability over number of charge discharge cycles is more for the lead acid battery having lower specific gravity of the electrolyte material (1.17 & 1.18) which makes these types of batteries more suitable for SLI applications in two, three or four wheelers where lesser output is sufficient whereas replacing the lead acid battery in a vehicle will cost more to the user of the vehicle.
[00027] In an embodiment, where there is requirement of high output capacity, the negative electrode 102 of the lead acid battery 100 is provided with the high surface area carbon additive material 105. By adding high surface area carbon additive material 105 like multiwall carbon nano-tube (MWCNT) to the negative electrode 102 it increases the active surface area for utilization on the negative electrode thereby enhancing the capacity of the battery up to 8-10%.
[00028] It is to be understood that the aspects of the embodiments are not necessarily limited to the features described herein. Many modifications and variations of the present subject matter are possible in the light of above disclosure. Therefore, within the scope of claims of the present subject matter, the present disclosure may be practiced other than as specifically described.