WO2013036226A1

WO2013036226A1 - Desulfation device

Info

Publication number: WO2013036226A1
Application number: PCT/US2011/050774
Authority: WO
Inventors: Jr. Daniel C. BIGGS
Original assignee: KUNMING DIBOO TECHNOLOGY Co Ltd; Canadus Power Systems LLC
Current assignee: KUNMING DIBOO TECHNOLOGY Co Ltd; Canadus Power Systems LLC
Priority date: 2011-09-08
Filing date: 2011-09-08
Publication date: 2013-03-14
Anticipated expiration: 2014-03-08

Abstract

An electronic battery desulfation system including a battery string, a desulfation device, a source of desulfation energy, a negative lead, a high voltage positive lead and a low voltage positive lead, wherein the negative lead and the high voltage positive lead are connected to the battery string to provide a voltage higher than the maximum operating voltage of the control circuitry of the desulfation device and the low voltage positive lead is connected to a point along the series string to provide a higher voltage than the negative lead and a lower voltage than the high voltage positive lead, wherein the desulfation device supplies desulfation energy to the battery string. The disclosed system can provide the required voltages to operate either without requiring the use of an internal power supply or with a power supply that is operating from a lower voltage than the high voltage positive lead. Vehicles comprising the desulfation system are also described.

Description

DESULFATION DEVICE

BACKGROUND

[0001] The present application is directed to electronic desulfation devices and, more particularly, to systems and methods for charging and electronically desulfating batteries.

[0002] Various deposits, such as crystallized lead sulfate deposits, often are generated as byproducts of the electro-chemical reaction that takes place when a battery is discharged. The accumulation of such deposits within the battery may degrade the operation of the battery and, if sufficient accumulation is present, may short circuit the battery.

[0003] Electronic desulfation devices have been developed to counteract the

accumulation of such deposits by applying desulfation energy, such as radio frequency energy, to the battery. Without being limited to any particular theory, it is believed that radio frequency energy, often delivered in pulses, breaks down the accumulated deposits and restores battery capacity lost due to the deposits.

[0004] Typical electronic desulfation devices are powered by the battery string or charging system they are connected to and utilize a two wire system, connected across the entire battery string, to both power the electronic circuitry and deliver the desulfation energy. Two wire, electronic desulfation devices that are connected to a battery string with a charging voltage that can exceed the maximum operating voltage of the control circuitry consisting of individual electronic circuits, typically digital circuits, require a power supply to lower the voltage supplied by the battery string to a level below the control circuit's maximum operating voltage in order to power and protect this electronic circuitry.

[0005] Accordingly, there is a need for a system and method for charging and electronically desulfating batteries that provides power for and protection to the control circuitry without requiring a separate power supply or without requiring a power supply that operates at the maximum battery string voltage. SUMMARY

[0006] In one aspect, the disclosed electronic battery desulfation system may include a battery string, an electronic desulfation device comprising control circuitry with a maximum operating voltage, a source of desulfation energy, a negative lead, a high voltage positive lead, wherein the desulfation device supplies desulfation energy to the battery string, and a low voltage positive lead, wherein the negative lead and the high voltage positive lead are connected to the battery string to provide a voltage higher than the maximum operating voltage of the control circuitry and the low voltage positive lead is connected to a point along the series string to provide a higher voltage than the negative lead and a lower voltage than the maximum operating voltage of the control circuitry. The disclosed system can provide the required voltages to operate the desulfation device without requiring the use of an internal power supply.

[0007] In another embodiment, the disclosed electronic battery desulfation system may include a battery string, an electronic desulfation device comprising control circuitry with a maximum operating voltage, a source of desulfation energy, a negative lead, a high voltage positive lead and a low voltage positive lead, wherein the negative lead and the high voltage positive lead are connected to the battery string to provide a voltage higher than the maximum operating voltage of the control circuitry and the low voltage positive lead is connected to a point along the series string to provide a higher voltage than the negative lead and a lower voltage than the high voltage positive lead, wherein the desulfation device supplies desulfation energy to the battery string. The disclosed system can provide the required voltages to operate the desulfation device with a power supply that is operating from a lower voltage than the high voltage positive lead.

[0008] In another embodiment, a battery powered vehicle containing a battery desulfation system is described. The battery desulfation system includes a battery string comprising a plurality of batteries, each battery including a positive terminal and a negative terminal and a desulfation device that supplies desulfation energy to the battery string. The desulfation device includes control circuitry having a maximum operating voltage, a source of desulfation energy, a negative lead, a high voltage positive lead and a low voltage positive lead, wherein the negative lead is connected to the negative terminal of a first battery and the high voltage positive lead is connected to the positive terminal of a second battery to provide a voltage higher than the maximum operating voltage of the control circuitry. The low voltage positive lead is connected to the positive terminal of the first battery to provide a higher voltage than the negative lead and a lower voltage than the high voltage positive lead.

[0009] In accordance with another aspect, the electronic battery desulfation system disclosed herein is used in conjunction with a vehicle. Examples of vehicles include, but are not limited to, battery powered scooters, electric bicycles, battery powered golf carts, and utility vehicles. The vehicle may contain a combustion engine or a fuel cell.

[0010] Other aspects of the disclosed battery electronic desulfation system will become apparent from the following description, the accompanying drawings and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] FIG. 1 is a block diagram of a first aspect of the disclosed battery desulfation system without a power supply, wherein the pulsation device comprises a three wire connection to a battery string with three batteries; and

FIG. 2 is a block diagram of a second aspect of the disclosed battery desulfation system with a power supply, wherein the pulsation device comprises a three wire connection to a battery string with three batteries.

DETAILED DESCRIPTION

[0012] Referring to FIG. 1, one embodiment of the disclosed electronic battery desulfation system, generally designated 10, may be used to provide an energy efficient battery bank. The system 10 includes a desulfation device 12 capable of providing desulfation energy and a battery string 14 having a plurality of cells 16. A battery string is illustrated in to FIG. 1 consisting of three batteries each with a plurality of cells connected in series. The term battery is used when multiple cells are manufactured as a single unit. In some cases, the terms cell and battery may be used interchangeably. Any number of cells or batteries can be used to provide the desired voltage for the string. Each of the cells in the string 14 may be connected in series to define a positive end 18 and a negative end 20 of the string 14. [0013] The cells 16 of the battery string 14 may be any appropriate electro-chemical cells, particularly rechargeable electro-chemical cells, and may include positive 22 and negative terminals 24 interconnected in series and may be made up of multiple cells to form a single battery. The battery string 14 may include individual cells connected in series or multiple batteries connected in series through interconnects 25. In one aspect, the cells 16 of the string 14 may be lead-acid cells, such as flooded lead-acid battery cells. The cells 16 may have a cell voltage such that the voltage of the string 14 may be calculated by multiplying the number of cells 16 in the string 14 by the cell voltage. For example, when the cell voltage is 2 volts and there are 18 cells in the string, the string 14 has a voltage of 36 volts.

[0014] The electronic desulfation device 12 includes control circuitry 26 with a maximum operating voltage, a source of desulfation energy 28, a negative lead 30, a high voltage positive lead 32 and a low voltage positive lead 34. The sources of desulfation energy 28 may be a desulfation device or any other appropriate assemblies or apparatus having circuitry or other appropriate components configured to deliver desulfation energy, possibly high-frequency voltage and current delivered to the associated battery cells in pulses. For example, the desulfation device may deliver voltage and current at a rate of about 10,000 cycles per second. Electronic desulfation devices such as pulsation devices are available from Canadus Power Systems of Cleveland, Ohio and are described in greater detail in U.S. Patent No. 5,648,714 to Eryou et al, the entire contents of which are incorporated herein by reference.

[0015] The desulfation device 12 typically includes control circuitry 26 adapted to facilitate the generation and communication of desulfation energy, such as radio frequency (RF) energy, to the battery. The control circuitry may be a digital circuit, processor, a control unit (e.g., an electronic control unit) or the like. The control circuitry 26 may control the amplitude and/or frequency of the desulfation energy being supplied to the battery as well as when the desulfation energy is applied to the battery 16. The control circuitry 26 may have circuits protecting it against reverse polarity connections or incorrect installation.

[0016] The control circuitry in a desulfation device typically has a maximum operating voltage. For example, devices based on CMOS technology may have a maximum operating voltage of 18 volts. The electronic desulfation device system disclosed herein provides a mechanism for providing a voltage of less than 18 volts even if the battery string voltage is over 18 volts by utilizing the described three wire connection between the desulfation device and the battery string.

[0017] As shown FIG. 1, desulfation device 12 may be connected to battery 16i at the negative end 20 of the battery string 14 and connected to battery I6₃ at the positive end 18 of the battery string. Desulfation device 12 may include a negative lead line 30 connected to the negative terminal 24 of battery I61, a low voltage positive lead line 34 connected to the positive terminal 22 of battery I6₁ and a high voltage positive lead line 26 connected to the positive terminal of battery I6₃. Therefore, the desulfation device 12 may receive the required operating voltage from the battery I6₁ which is maintained below the maximum operating voltage of the control circuitry 26 in the desulfation device 12. As such, the control circuitry's positive supply requirements may be powered from the low voltage positive lead 34.

[0018] In accordance with another embodiment, the desulfation device 12 may be connected to other cells in the battery string 14 provided the voltage to power the control circuitry 26 from the negative lead line 30 to the low voltage positive lead line 34 from the cell or cells is below the maximum operating voltage of the control circuitry. By doing so, the disclosed system can function without requiring a separate internal power supply to power and protect the control circuitry in the desulfation device. Therefore, the unit can be smaller, more energy efficient and more reliable than units requiring an additional power supply.

[0019] In accordance with yet another embodiment as shown in FIG. 2, the desulfation device may be connected to other cells in the battery string 14 provided the voltage to power the control circuitry from the negative lead line 30 and low voltage positive lead line 34 is below the voltage of the high voltage lead line 32. This voltage may be greater than the maximum voltage of the control circuitry and thereby require a power supply 36, but by doing so the disclosed system can function with a power supply that is operating at a lower voltage than the high voltage lead line 32 with respect to the low voltage lead line 34. This is particularly advantageous when the power supply 36 is a linear type. Therefore, the unit can be smaller, more energy efficient and more reliable than units requiring a power supply operating from the high voltage lead line 32 or from full voltage of the battery string.

[0020] Although the systems described herein refer to connecting a lead to a terminal of a cell or battery, one of ordinary skill in the art will appreciate that the connections could be located at various points along the battery string such as the interconnect 25 between cells or batteries or an adjacent battery terminal with a direct electrical connection to a particular terminal.

[0021] The present application will be described in more detail by reference to the following non-limiting examples.

[0022] 60 Volt electric scooter with 6 cell / 12 volt VRLA batteries:

[0023] In this example the battery string is made up of 5 - 12 volt batteries in series for a total nominal voltage of 60 Volts. The peak charging voltage for these VRLA batteries is 2.3 volts per cell (vpc) so if this battery bank were being properly charged, the maximum charging voltage would be 30 cells X 2.3vpc = 69 volts or 13.8 volts per battery.

Conventional desulfation units with only two wires would need some form of power supply, switching power supply, DC to DC converter, Linear Voltage Regulator, Zener Diode, or the like to power and protect the control circuitry by limiting the maximum voltage of the control circuitry, possibly digital circuitry, or individual components. The maximum voltage of this control circuitry would typically be a voltage less than 20V depending on the technology used. For the purpose of this example, the control circuitry used is digital CMOS circuitry (maximum voltage = 18Volts) and requires 10mA at an operating voltage of 13.8V to perform its function. In this case the digital electronics are consuming 138mW.

[0024] An inexpensive way of addressing this issue would be to provide some type of linear power supply. However, a linear power supply would not be very efficient. 10mA would be flowing at the full 69 volts for a total power consumption of 690mW or a total efficiency of 20% with 552mW being wasted. Additionally, the power supply would consist of a number of components increasing the size of the circuit board. [0025] A more efficient way of doing this would be a switching power supply. These power supplies can operate at >80% efficiency but they are more expensive. A switching power supply would require an additional integrated circuit and most likely one or more capacitors, diodes, and inductors or transformers. All of these components take up more space requiring a larger circuit board. Because an electronic desulfation unit is a relatively simple device this switching power supply could account for 20% or more of the total circuit board cost.

[0026] The 3 wire desulfation device of the present example takes advantage of the voltage of the first battery in the string. With a maximum voltage of 13.8 volts the digital electronics, CMOS in this case, can be powered directly from this power source, the first battery in a larger string. No power supply is required and therefore it can run at 100% efficiency. Additionally, without the power supply there are no additional components, so the board can be smaller than the other two options. The three wire desulfation device is the least expensive and most efficient solution. Because there are less components and less heat from greater efficiency this unit should also prove to be more reliable that the first two options.

[0027] 64 Volt electric scooters with 8 cell / 16 volt VRLA batteries:

[0028] In this example the battery string is made up of 4 - 16 volt batteries in series for a total nominal voltage of 64 Volts. The peak charging voltage for these VRLA batteries is 2.3 volts per cell (vpc) so if this battery bank were being properly charged the maximum charging voltage would be 32 cells X 2.3vpc = 73.6 volts or 18.4 volts per battery.

Conventional desulfation units with only two wires would need some form of power supply, switching power supply, DC to DC converter, Linear Voltage Regulator, Zener Diode, or the like to power and protect the control circuitry by limiting the maximum voltage of the control circuitry, possibly digital circuitry, or individual components. The maximum voltage of this control circuitry would typically be a voltage less than 20V depending on the technology used. For the purpose of this example, the control circuitry used is digital CMOS circuitry (maximum voltage = 18Volts) and requires 10mA at an operating voltage of 14.4V to perform its function. In this case the control circuitry is consuming 144mW. [0029] Just as in the first example a liner power supply operating across the entire battery string, 73.6 volts, would be inefficient and a switching power supply would be costly. Where this example differs from the first example is that the individual battery voltage is 18.4 volts which is above the 18 volt, maximum operating voltage, of the digital CMOS component. Here the three wire desulfation device also provides an advantage. In this case a power supply could be used to drop the voltage of the first battery, 18.4 volts, down to a voltage, possibly 14.4 volts, below the maximum operating voltage of the CMOS component. A linear power supply may be well suited in this example because of its low cost and relatively good efficiency, having to only reduce the voltage 4 volts rather than the 76.3V - 14.4V = 59.2 volts if it were operating from the total battery string. The total power consumed in this system would be 18.4V x 10mA = 184mW with 44mW being wasted and a total efficiency of 144mW / 184mW = 78%. An efficiency of 78% puts it in a range comparable with a switching power supply. However, a switching power supply would likely be much more costly and take up considerably more board space. Therefore the three wire desulfation can be advantageous even when the lowest available voltage, due to the battery string configuration, is above the maximum operating voltage of individual components such as digital components.

[0030] Although various aspects of the disclosed desulfation system have been shown and described, modifications may occur to those skilled in the art upon reading the specification. The present application includes such modifications and is limited only by the scope of the claims.

[0031] What is claimed is:

Claims

1. A battery desulfation system comprising:

a battery string comprising a plurality of cells, each cell including a positive terminal and a negative terminal;

a desulfation device comprising control circuitry having a maximum operating voltage, a source of desulfation energy, a negative lead, a high voltage positive lead and a low voltage positive lead, wherein the negative lead and the high voltage positive lead are connected to the battery string to provide a voltage higher than the maximum operating voltage of the control circuitry and the low voltage positive lead is connected to a point along the series string to provide a higher voltage than the negative lead and a lower voltage than the high voltage positive lead, wherein the desulfation device supplies desulfation energy to the battery string.

2. The system of claim 1 wherein said system does not include a separate or internal power supply.

3. The system of claim 1 wherein said system does not include a switching power supply, DC to DC converter, or linear type power supply.

4. The system of claim 1 wherein the control circuitry's positive supply requirements are powered from the low voltage positive lead.

5. The system of claim 1 wherein said plurality of cells are lead-acid battery cells.

6. The system of claim 1 wherein said desulfation energy is radio frequency energy

delivered in pulses.

7. The system of claim 1 wherein said control circuitry is CMOS based, processor based, or digital circuitry.

8. The system of claim 1 wherein said control circuitry controls at least one of:

(a) the amplitude of the desulfation energy,

(b) the frequency of the desulfation energy; and (c) the timing as to when to apply the desulfation energy.

9. The system of claim 1 wherein said battery string comprises individual cells connected in series or multiple batteries connected in series.

10. The system of claim 1 wherein said negative lead is connected to the negative terminal of a cell in a first battery and the low voltage positive lead is connected to the positive terminal of another cell in said first battery.

1 1. The system of claim 10 wherein said first cell is at the negative end said battery string.

12. The system of claim 1 wherein the high voltage positive lead is connected to the

positive terminal of the last cell of said battery string at the positive end of the battery string.

13. The system of claim 1 wherein said system includes a power supply that is operating from a lower voltage than the high voltage lead.

14. The system of claim 13 wherein said power supply is a linear type power supply, a switching power supply or DC to DC converter.

15. The system of claim 13 wherein said power supply is powering the control circuitry or protecting the control circuitry from being damaged by its supply voltage exceeding its maximum rating.

16. A vehicle comprising the system of any one of the preceding claims.

17. A vehicle according to claim 16 wherein said vehicle is a battery powered scooter, electric bicycle, battery powered golf cart or utility vehicle.

18. A vehicle according to claim 16 wherein said vehicle contains a combustion engine.

19. A vehicle according to claim 16 wherein said vehicle has a fuel cell.

20. A battery powered vehicle containing a battery desulfation system wherein said battery desulfation system comprises:

a battery string comprising a plurality of batteries, each battery including a positive terminal and a negative terminal;

a desulfation device comprising control circuitry having a maximum operating voltage, a source of desulfation energy, a negative lead, a high voltage positive lead and a low voltage positive lead, wherein the negative lead is connected to the negative terminal of a first battery and the high voltage positive lead is connected to the positive terminal of a second battery to provide a voltage higher than the maximum operating voltage of the control circuitry and the low voltage positive lead is connected to the positive terminal of the first battery to provide a higher voltage than the negative lead and a lower voltage than the high voltage positive lead, wherein the desulfation device supplies desulfation energy to the battery string.