WO2015179944A1

WO2015179944A1 - Starter battery

Info

Publication number: WO2015179944A1
Application number: PCT/CA2014/050498
Authority: WO
Inventors: Stewart Neil Simmonds; Johannes Christian KRUGER
Original assignee: Corvus Energy Ltd.
Priority date: 2014-05-28
Filing date: 2014-05-28
Publication date: 2015-12-03

Abstract

A starter battery that includes a starter terminal for starting a starter motor and a hotel terminal for charging the starter battery and for powering hotel loads of a vehicle. The starter and hotel terminals are electrically connected in parallel to a positive terminal of one or more battery cells, which are contained with the starter battery's housing. The positive and hotel terminals are accessible from the outside of the starter battery's housing, as is a negative terminal that is electrically connected to a negative terminal of the one or more battery cells.

Description

STARTER BATTERY

TECHNICAL FIELD

[0001] The present disclosure is directed at a starter battery. More particularly, the present disclosure is directed at a lithium ion starter battery.

BACKGROUND

[0002] A starter motor is typically used to start an internal combustion engine.

Both the engine and the starter motor are connected to a crankshaft, and during ignition the starter motor rotates the crankshaft until the engine is able to operate using its own power. The starter motor shuts off once the engine becomes self-sustaining.

[0003] Starter motors are often electrically powered using a lead acid starter battery. Research and development continue, however, into starter batteries of different chemistries.

SUMMARY

[0004] According to a first aspect, there is provided a starter battery. The starter battery comprises a battery cell comprising a positive terminal and a negative terminal; a starter terminal and a hotel terminal electrically coupled in parallel to the positive terminal of the battery cell; and a negative terminal electrically coupled to the negative terminal of the battery cell.

[0005] The starter battery may further comprise voltage monitoring circuitry electrically coupled across the battery cell to monitor the voltage of the battery cell; switching circuitry electrically coupled between the hotel terminal and the positive terminal of the battery cell that allows current to flow between the positive terminal of the battery cell and the hotel terminal when closed and prevents current from flowing between the positive terminal of the battery cell and the hotel terminal when open; a processor communicatively coupled to the switching circuitry and the voltage monitoring circuitry; and a non-transitory computer readable medium communicatively coupled to the processor and storing instructions to cause the processor to perform a method comprising: (i)determining whether a first fault condition exists; and (ii) when the first fault condition does not exist, driving the switching circuitry closed.

[0006] The method the processor performs may further comprise when the first fault condition exists, driving the switching circuitry open.

[0007] The first fault condition may comprise the battery cell having a voltage above a high voltage threshold.

[0008] The starter battery may further comprise a starter interlock communicatively coupled to the processor, and the method the processor performs may further comprise determining whether a second fault condition exists; and when the second fault condition does not exist, closing the starter interlock.

[0009] The method the processor performs may further comprise when the second fault condition exists, opening the starter interlock. The second fault condition may comprise the battery cell having a voltage below a low voltage threshold.

[0010] Each of the fault conditions may comprise any one or more of whether the battery cell is below a low voltage threshold, whether the battery cell exceeds a high voltage threshold, whether the battery cell has a temperature less than a low temperature threshold, whether the battery cell has a temperature exceeding a high temperature threshold, and whether a key is in an ignition of a vehicle powered by the starter battery.

[0011] The fault conditions may be identical to each other.

[0012] According to another aspect, there is provided a system for starting an internal combustion engine. The system comprises a battery cell comprising a positive terminal and a negative terminal; a starter terminal and a hotel terminal electrically coupled in parallel to the positive terminal of the battery cell; a negative terminal electrically coupled to the negative terminal of the battery cell; a starter motor electrically coupled between the starter terminal and the negative terminal; an ignition switch electrically coupled to the starter motor and starter terminal such that the ignition switch prevents current from flowing through the starter motor when open and allows current to flow through the starter motor when closed; and an alternator electrically coupled between the hotel terminal and the negative terminal.

[0013] The system may further comprise voltage monitoring circuitry electrically coupled across the battery cell to monitor the voltage of the battery cell; switching circuitry electrically coupled between the alternator and the positive terminal of the battery cell that allows current to flow between the positive terminal of the battery cell and the alternator when closed and prevents current from flowing between the positive terminal of the battery cell and the alternator when open; a processor communicatively coupled to the switching circuitry and the voltage monitoring circuitry; and a non- transitory computer readable medium communicatively coupled to the processor and storing instructions to cause the processor to perform a method comprising (i) determining whether a first fault condition exists; and (ii) when the first fault condition does not exist, driving the switching circuitry closed.

[0014] The method the processor performs may further comprise when the first fault condition exists, driving the switching circuitry open. The first fault condition may comprise the battery cell having a voltage above a high voltage threshold.

[0015] The system may further comprise a starter interlock communicatively coupled to the processor and electrically coupled in series with the ignition switch, and the method the processor performs may further comprise determining whether a second fault condition exists; and when the second fault condition does not exist, closing the starter interlock. [0016] The method the processor performs may further comprise when the second fault condition exists, opening the starter interlock. The second fault condition may comprise the battery cell having a voltage below a low voltage threshold.

[0017] The fault condition may be selected from the group comprising whether the battery cell is below a low voltage threshold, whether the battery cell equals or exceeds the high voltage threshold, whether the battery cell has a temperature equal to or less than a low temperature threshold, whether the battery cell has a temperature equaling or exceeding a high temperature threshold, and whether a key is in an ignition that comprises the ignition switch.

[0018] The fault conditions may be identical to each other.

[0019] According to another aspect, there is provided a method for charging a starter battery. The method comprises determining whether a first fault condition exists; and charging the starter battery when the first fault condition does not exist, wherein the starter battery comprises: a battery cell comprising a positive terminal and a negative terminal; a starter terminal and a hotel terminal electrically coupled in parallel to the positive terminal of the battery cell; and a negative terminal electrically coupled to the negative terminal of the battery cell. According to this aspect, the starter battery is charged only via the hotel terminal.

[0020] The method may further comprise when the first fault condition exists, preventing the starter battery from being charged by driving open switching circuitry, with the switching circuitry being electrically coupled between the hotel terminal and the positive terminal of the battery cell.

[0021] The first fault condition may comprise the battery cell having a voltage above a high voltage threshold. [0022] The method may further comprise determining whether a second fault condition exists; and when the second fault condition does not exist, powering a starter motor only via the starter terminal.

[0023] The method may further comprise when the second fault condition exists, preventing the starter battery from powering the starter motor by opening a starter interlock. The second fault condition comprises the battery cell having a voltage below a low voltage threshold.

[0024] The fault condition may be selected from the group comprising whether the battery cell is below a low voltage threshold, whether the battery cell equals or exceeds the high voltage threshold, whether the battery cell has a temperature equal to or less than a low temperature threshold, whether the battery cell has a temperature equaling or exceeding a high temperature threshold, and whether a key is in an ignition of a vehicle powered by the starter battery.

[0025] The fault conditions are identical to each other.

[0026] According to another aspect, there is provided a non-transitory computer readable medium having encoded thereon instructions to cause a processor to perform a method for charging a starter battery, the method comprising determining whether a first fault condition exists; and charging the starter battery when the first fault condition does not exist, wherein the starter battery comprises (i) a battery cell comprising a positive terminal and a negative terminal; (ii) a starter terminal and a hotel terminal electrically coupled in parallel to the positive terminal of the battery cell; and (iii) a negative terminal electrically coupled to the negative terminal of the battery cell. According to this aspect, the starter battery is charged only via the hotel terminal.

[0027] This summary does not necessarily describe the entire scope of all aspects.

Other aspects, features and advantages will be apparent to those of ordinary skill in the art upon review of the following description of specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In the accompanying drawings, which illustrate one or more example embodiments:

[0029] FIG. 1 is a block diagram of a system for starting an internal combustion engine, according to one embodiment.

[0030] FIGS. 2 and 3 are perspective views of a starter battery encased in an enclosure, according to another embodiment.

[0031] FIGS. 4 and 5 are flowcharts depicting example methods for managing a starter battery, according to additional embodiments.

DETAILED DESCRIPTION

[0032] Directional terms such as "top", "bottom", "upwards", "downwards",

"vertically", and "laterally" are used in the following description for the purpose of providing relative reference only, and are not intended to suggest any limitations on how any article is to be positioned during use, or to be mounted in an assembly or relative to an environment. Additionally, the term "couple" and variants of it such as "coupled", "couples", and "coupling" as used in this description is intended to include indirect and direct connections unless otherwise indicated. For example, if a first device is coupled to a second device, that coupling may be through a direct connection or through an indirect connection via other devices and connections. Similarly, if the first device is communicatively coupled to the second device, communication may be through a direct connection or through an indirect connection via other devices and connections.

[0033] Starter batteries have two uses. They are primarily used to power a starter motor, which rotates the crankshaft of a vehicle's internal combustion engine during ignition until the engine is able to sustain itself on its own power. They are also used to supply hotel loads to electrical equipment in the vehicle when the engine is off. These hotel loads can include, for example, the vehicle's emergency lights, radio, and internal lighting. The current draw from the starter battery can be between 1,500 A to 3,000 A for a duration of 10 to 30 seconds when the starter battery is being used to power the starter motor. The current draw from the starter battery is lower when it is only being used to power hotel loads: the current draw can be up to 100 A and can be expected to last for up to 2 hours.

[0034] Starter batteries are often lead acid batteries. They are typically constructed to output 12 V DC and store between 100 Ah to 200 Ah of energy. Lead acid batteries have two terminals, one positive and one negative. A lead acid battery typically has no monitoring or safety electronics to monitor or regulate the currents entering and leaving the battery or the voltage of the battery. Lead acid batteries typically have a life cycle of around 200 charge/discharge cycles, an operating temperature range of between 0 °C and 40 °C, a specific energy of 25 Wh/kg, and a specific power of 180 W/kg.

[0035] In contrast, lithium ion batteries typically have a specific energy of 160

Wh/kh, a specific power of 2,800 W/kh, a life cycle that can exceed 5,000 charge/discharge cycles, and an operating temperature range of between -20 °C and 60 °C. Lithium ion batteries clearly have an advantage over lead acid batteries when considering these criteria.

[0036] However, one drawback of lithium ion batteries is that the consequences of not adhering to the upper and lower operating voltages of the batteries can be severe. Discharging a lithium ion battery below its minimum operating voltage (typically around 2.7 V) can permanently damage the battery. Charging a lithium ion battery above its maximum operating voltage can compromise safety. Accordingly, lithium ion batteries typically include safety electronics that ensure the battery does not overcharge or excessively discharge. However, safety electronics that can accommodate currents of up to 3,000 A, as may be encountered when starting an engine, are large and expensive. As alluded to above, lead acid batteries do not require safety electronics and do not encounter this problem. [0037] The embodiments described herein are directed at a battery, and in particular a lithium ion battery, that has two positive terminals: a starter terminal for outputting the relatively high currents used to power a vehicle's starter motor, and a hotel terminal for outputting the relatively low currents used to power the vehicle's hotel loads. All charging of the battery is done using the hotel terminal. Switching circuitry is included within the battery and is placed in series with the hotel terminal. The switching circuitry can disconnect the hotel terminal from the battery cells to prevent excessive charging or discharging. As the hotel terminal is not used to conduct the relatively large currents used to power the starter motor, the switching circuitry is not prohibitively large and expensive. Circuitry within the starter motor is used to prevent excessive discharging through the starter terminal, and no circuitry is needed to prevent excessive charging through the starter terminal as the starter terminal is not used for charging.

[0038] Referring now to FIG. 1, there is shown a block diagram of a system 150 for starting an internal combustion engine, according to one embodiment. The system 150 includes a lithium ion starter battery 100 having a starter terminal 138 and a hotel terminal 140 (collectively, the "output terminals 138, 140"), which share a common negative terminal 142. Each of the output terminals 138, 140 is electrically coupled to the positive ends of battery cells 102 suitably configured to provide the requisite voltage and amperage. For example, in the depicted embodiment the battery cells 102 are connected in a 3s 4p arrangement, but in an alternative embodiment may be connected differently. The negative ends of the battery cells 102 are connected to the negative terminal 142. Each group of four cells connected in parallel is connected across cell balancing and monitoring circuitry 104 ("B&M circuitry 104") that operates to monitor the voltages in the cells 102 and to maintain the cells 102 at approximately identical voltages. The B&M circuitry 104 accordingly acts as a form of voltage monitoring circuitry.

[0039] The B&M circuitry 104 is connected to and sends digitized readings of the cells 102 to a microprocessor 108. The microprocessor 108 is powered by a voltage regulator 110 that is connected to the cells 102 and that outputs a stable DC voltage to the microprocessor 108. Also connected to the microprocessor 108 is a CA Bus interface 106 to allow the microprocessor 108 to communicate with other vehicle systems, a starter interlock 114 that allows the microprocessor 108 to prevent engine ignition if a fault condition is present, an optical isolator 116 that is connected across the starter interlock 114, temperature sensors 112 to measure the battery cells' 102 temperature, a DC shunt 124 connected in series with the cells 102 to measure the current being drawn from the cells 102, driving circuitry 118 for actuating semiconductor switching circuitry in the form of MOSFET switches 122, and safety circuitry 120 connected to the driving circuitry 118. The microprocessor 108 is able to determine the battery cells' 102 state of charge (in %) and state-of-health (in %) from factors such as the current drawn from the battery cells 102.

[0040] The switches 122 are located along a hotel load conductor 126 that connects the hotel terminal 140 to the shunt 124. In the depicted embodiment, the hotel terminal 140 is designed to output a maximum of 150 A of current, and the switches 122 are accordingly designed to be able to switch this much current on and off. In alternative embodiments, instead of semiconductor based switching circuitry mechanical switches, such as relays, may be used.

[0041] A starter load conductor 128 connects the starter terminal 138 to the shunt

124. In the depicted embodiment, the starter terminal 138 is designed to output a maximum of 1,500 A of current and has no circuitry corresponding to the switches 122 on the hotel load conductor 126. As discussed in further detail below, limiting the switches 122 to use with hotel loads allows the switches 122 to be constructed economically and at a reasonable size for use within the battery 100.

[0042] The system 150 also includes vehicle-side circuitry 146 that is connected to and powered by the battery 100 when the battery 100 is installed into the vehicle (not shown). The vehicle-side circuitry 146 includes an alternator 130 connected in series to the hotel terminal 140 and a starter motor 136 connected in series to the starter terminal 138. Also connected to the starter terminal 138 are an ignition switch 132 and a starter relay 134 whose coil is connected in series between the ignition switch 132 and the starter interlock 1 14. When an operator closes the ignition switch 132, the microprocessor 108 detects a voltage change via the optical isolator 1 16 and, assuming there are no fault conditions as described below, closes the starter interlock 1 14. The starter relay 134 consequently closes and voltage from the starter terminal 138 closes a contactor 137 within the starter motor 136 to permit up to 1,500 A of current from the starter terminal 138 to pass through the starter motor 136.

[0043] FIGS. 2 and 3 show perspective views of the exterior of the battery 100, according to one embodiment. Visible from the exterior are an enclosure 200 that encases the circuitry shown in FIG. 1. On the front surface of the battery 100 are the starter and hotel terminals 138, 140. On the rear surface of the battery are the common terminal 142, the starter interlock 1 14, the CANBus interface 106, and battery status LEDs 1 15.

Operation

[0044] In two depicted example embodiments, the microprocessor 108 performs example methods 400,500 for managing the battery 100 as shown in FIGS. 4 and 5 when the battery 100 is installed in the vehicle. In typical usage, the microprocessor 108 repeatedly performs the methods 400,500 when the battery 100 is installed in the vehicle. The method 500 of FIG. 5 helps to ensure that the battery 100 does not become overcharged or undercharged, while the method 400 of FIG. 4 is directed more generally at helping to ensure that the battery 100 is only used when no fault conditions are present. As used herein, a "fault condition" refers to any one or more of the following:

(a) whether any one or more of the battery cells 102

(i) are below a low voltage threshold (e.g. a threshold indicative of a minimum state of charge below which the battery cells 102 cannot be used without damaging them); (ii) exceed the high voltage threshold (e.g. a threshold indicative of a maximum state of charge above which the battery cells 102 cannot be used without damaging them);

(iii) have a temperature less than a low temperature threshold (e.g. a threshold at or below which the battery cells 102 cannot be safely charged); and

(iv) have a temperature exceeding a high temperature threshold (e.g. a threshold at or above which the battery cells 102 cannot safely be discharged without risk of, for example, thermal runaway); and

(b) whether a key is in an ignition of the vehicle.

[0045] However, in alternative embodiments (not depicted), additional and alternative fault conditions are possible.

[0046] Furthermore, in alternative embodiments, instead of performing the methods 400,500 in a loop the microprocessor 108 may utilize interrupts or another suitable notification tool to determine whether a fault condition is present and what corresponding action to take.

[0047] Referring now to FIG. 4, in one example scenario (the "normal operating scenario"), the battery 100 is neither overcharged nor undercharged. The microprocessor 108 uses the battery cells' 102 voltage as a proxy for state of charge and measures the cells' 102 voltage using the B&M circuitry 104. The microprocessor 108 begins the method 400 at block 401 and proceeds to block 402 at which it considers a first fault conditions by determining that the cells 102 are not below a low voltage threshold and are accordingly not undercharged. Because the cells 102 are not undercharged the battery 100 may be used to power the starter motor 136 without risk of battery damage; the microprocessor 108 accordingly proceeds to block 406 and closes the starter interlock 1 14. The microprocessor 108 then proceeds to block 408 at which it considers a second fault condition by determining that the cells 102 do not exceed a high voltage threshold and are accordingly not overcharged. Because the battery 100 is not overcharged it may be charged via the hotel terminal 140 without risk of battery damage; the microprocessor 108 accordingly proceeds to block 412 and drives the driving circuitry 118 to close the switches 122. After closing the switches 122 the microprocessor 108 returns to block 402. In the normal operating scenario the battery 100 does not become overcharged or undercharged and the microprocessor 108 accordingly does not have to open the starter interlock 114 or open the switches 122.

[0048] In the normal operating scenario, an operator of the vehicle who wants to start the vehicle's engine closes the ignition switch 132. Because the starter interlock 114 is also closed, closing the ignition switch 132 closes the starter relay 134, which accordingly closes the connector 136 and allows up to 1,500 A to flow out of the starter terminal 138 and through the starter motor 136. This starts the starter motor 136, which eventually starts the engine. Once the engine has started the alternator 130 recharges the battery 100 via the hotel terminal 140, which is possible because the switches 122 are closed.

[0049] In another example scenario (the "undercharge prevention scenario"), the microprocessor 108 detects that the cells 102 are at or below their low voltage threshold and responds accordingly. The cells 102 may be below their low voltage threshold because, for example, of power drawn by the B&M circuitry 104. While performing the method 400, instead of proceeding from block 402 to block 406 as is done in the normal operating scenario, the microprocessor 108 proceeds from block 402 to block 404 and opens the starter interlock 114. After opening the starter interlock 114 the microprocessor 108 returns to block 402 to repeat the method 400. When the starter interlock 114 is open, closing the ignition switch 132 does not close the starter relay 134 because the open starter interlock 114 prevents any current from passing through the starter relay's 134 coil. Because the starter relay 134 doesn't close, neither does the contactor 137 within the starter motor 136, and the starter motor 136 accordingly draws no current from the cells 102 thereby preventing the cells 102 from further discharging and causing battery damage.

[0050] In another example scenario (the "overcharge prevention scenario"), the microprocessor 108 detects that the cells 102 are at their high voltage threshold and responds accordingly. While performing the method 400, instead of proceeding from block 408 to block 412 as is done in the normal operating scenario, the microprocessor 108 proceeds from block 408 to block 410 and opens the switches 122. After opening the switches 122 the microprocessor 108 returns to block 402 to repeat the method 400. When the switches 122 are open, the alternator 130 cannot charge the battery 100 because there is no current path from the alternator 130 to the cells 102. The battery 100 is thereby prevented from overcharging that could damage it and compromise safety.

[0051] In FIG. 4, the only fault condition the microprocessor 108 checks when determining whether to close the starter interlock 114 is whether the cells 102 have a voltage less than the low voltage threshold (block 402), and the only fault condition the microprocessor 108 checks when determining whether to close the switches 122 is whether the cells 102 have a voltage greater than the high voltage threshold (block 408). In the method 400 of FIG. 4, the microprocessor 108 accordingly checks one subset of the possible fault conditions when determining whether to close the starter interlock 1 14 and another subset of the possible fault conditions when determining whether to close the switches 122. While in FIG. 4 the microprocessor 108 considers different subsets of the fault conditions when determining whether to close the starter interlock 114 and to close the switches 122, in an alternative embodiment (not depicted) the microprocessor 108 may consider the same subsets of the fault conditions when determining whether to close the starter interlock 114 and to close the switches 122. While in FIG. 4 the subset of fault conditions comprises only a single type of fault, in alternative embodiments the subsets of fault conditions considered may comprise multiple possible fault conditions. For example, in an alternative embodiment such as in the method 500 of FIG. 5, the microprocessor 108 may consider all of the fault conditions when determining whether to close the starter interlock 114 and to close the switches 122.

[0052] In FIG. 5, the microprocessor 108 begins performing the method 500 at block 501 and proceeds to block 502 at which it determines whether any of the fault conditions exist. The microprocessor 108 determines whether the cells 102 have a voltage below the low voltage threshold or above the high voltage threshold, are at a temperature below the low temperature threshold or above the high temperature threshold, or whether the key is not in the vehicle's ignition. If any of these fault conditions are present, the microprocessor 108 proceeds to block 504 where it opens the starter interlock 114 and then proceeds to block 506 where it opens the switches 122, following which it returns back to block 502. Opening the starter interlock 114 and the switches 122 prevents the starter battery 100 from being charged, from being used to power hotel loads, and from being used to start the starter motor 136. If none of these fault conditions are present, the microprocessor 108 proceeds to block 508 where it closes the starter interlock 114 and then proceeds to block 510 where it closes the switches 122, following which it returns back to block 502. Closing the starter interlock 114 and the switches 122 permits the starter battery 100 to be charged, to power hotel loads, and to be used to start the starter motor 136. The method 500 of FIG. 5 is more conservative than the method 400 of FIG. 4 in that if any of the fault conditions is present the starter battery 100 will for practical purposes cease to function until all of the fault conditions have been eliminated.

[0053] In another alternative embodiment (not depicted), once the microprocessor

108 detects any one or more of the fault conditions, it permanently opens the starter interlock 114 and the switches 122 in anticipation of being replaced. This may happen, for example, if the microprocessor 108 detects that the temperature of the cells 102 has exceeded a level associated with thermal runaway, and that one or both of charging and discharging of cells 102 is to be ceased for safety reasons.

[0054] While the embodiment depicted in FIG. 1 uses an example current of approximately 1,500 A for the starter load and approximately 150 A for the hotel load, in alternative embodiments one or both of these loads may be higher or lower. For example, in one alternative embodiment the starter load may be 3,000 A and the hotel load may be 250 A.

[0055] The methods 400,500 may be encoded on to any suitable type of computer readable medium for execution by the microprocessor 108 or another suitable processor. Suitable non-transitory computer readable media include, for example, primary storage devices (e.g. any type of random access memory, whether referred to as RAM or ROM) and secondary storage devices (e.g. hard drives, floppy disks, CD or DVD ROMs, ZIP disks, tapes, magnetic storage devices, optical storage devices, MEMS, nano- technological storage devices, flash memory). Suitable processors include, for example, processors, microprocessors, controllers, microcontrollers, ASICs, FPGAs, and PICs.

[0056] While the starter battery 100 depicted in FIG. 1 shows the microprocessor

108, switches 122, B&M circuitry 104, and starter interlock 1 14 within the starter battery 100 itself, in alternative embodiments (not depicted) these particular components or other components of the starter battery 100 can be located outside the starter battery 100 and elsewhere within the system 150, such as within the vehicle itself.

[0057] It is contemplated that any part of any aspect or embodiment discussed in this specification can be implemented or combined with any part of any other aspect or embodiment discussed in this specification.

[0058] For the sake of convenience, the example embodiments above are described as various interconnected functional blocks or distinct software modules. This is not necessary, however, and there may be cases where these functional blocks or modules are equivalently aggregated into a single logic device, program or operation with unclear boundaries. In any event, the functional blocks and software modules or features of the flexible interface can be implemented by themselves, or in combination with other operations in either hardware or software. [0059] FIGS. 4 and 5 are flowcharts of example methods. Some of the blocks illustrated in these flowcharts may be performed in an order other than that which is described. Also, it should be appreciated that not all of the blocks described in the flowcharts are required to be performed, that additional blocks may be added, and that some of the illustrated blocks may be substituted with other blocks.

[0060] While particular embodiments have been described in the forgoing, it is to be understood that other embodiments are possible and are intended to be included herein. It will be clear to any person skilled in the art that modifications of and adjustments to the forgoing embodiments, not shown are possible.

Claims

1. A starter battery, comprising:

(a) a battery cell comprising a positive terminal and a negative terminal;

(b) a starter terminal and a hotel terminal electrically coupled in parallel to the positive terminal of the battery cell; and

(c) a negative terminal electrically coupled to the negative terminal of the battery cell.

2. The starter battery of claim 1 further comprising:

(a) voltage monitoring circuitry electrically coupled across the battery cell to monitor the voltage of the battery cell;

(b) switching circuitry electrically coupled between the hotel terminal and the positive terminal of the battery cell that allows current to flow between the positive terminal of the battery cell and the hotel terminal when closed and prevents current from flowing between the positive terminal of the battery cell and the hotel terminal when open;

(c) a processor communicatively coupled to the switching circuitry and the voltage monitoring circuitry; and

(d) a non-transitory computer readable medium communicatively coupled to the processor and storing instructions to cause the processor to perform a method comprising:

(i) determining whether a first fault condition exists; and

(ii) when the first fault condition does not exist, driving the switching circuitry closed.

3. The starter battery of claim 2 wherein the method further comprises when the first fault condition exists, driving the switching circuitry open.

4. The starter battery of claims 2 or 3 wherein the first fault condition comprises the battery cell having a voltage above a high voltage threshold.

5. The starter battery of claims 2 or 3 further comprising a starter interlock communicatively coupled to the processor, and wherein the method further comprises:

(a) determining whether a second fault condition exists; and

(b) when the second fault condition does not exist, closing the starter interlock.

6. The starter battery of claim 5 wherein the method further comprises when the second fault condition exists, opening the starter interlock.

7. The starter battery of claims 5 or 6 wherein the second fault condition comprises the battery cell having a voltage below a low voltage threshold.

8. The starter battery of claims 5 or 6 wherein each of the fault conditions comprises any one or more of whether the battery cell is below a low voltage threshold, whether the battery cell exceeds a high voltage threshold, whether the battery cell has a temperature less than a low temperature threshold, whether the battery cell has a temperature exceeding a high temperature threshold, and whether a key is in an ignition of a vehicle powered by the starter battery.

9. The starter battery of claim 8 wherein the fault conditions are identical to each other.

10. A system for starting an internal combustion engine, the system comprising: a battery cell comprising a positive terminal and a negative terminal; (b) a starter terminal and a hotel terminal electrically coupled in parallel to the positive terminal of the battery cell;

(c) a negative terminal electrically coupled to the negative terminal of the battery cell;

(d) a starter motor electrically coupled between the starter terminal and the negative terminal;

(e) an ignition switch electrically coupled to the starter motor and starter terminal such that the ignition switch prevents current from flowing through the starter motor when open and allows current to flow through the starter motor when closed; and

(f) an alternator electrically coupled between the hotel terminal and the negative terminal.

11. The system of claim 10 further comprising:

(b) switching circuitry electrically coupled between the alternator and the positive terminal of the battery cell that allows current to flow between the positive terminal of the battery cell and the alternator when closed and prevents current from flowing between the positive terminal of the battery cell and the alternator when open;

(c) a processor communicatively coupled to the switching circuitry and the voltage monitoring circuitry; and (d) a non-transitory computer readable medium communicatively coupled to the processor and storing instructions to cause the processor to perform a method comprising:

(i) determining whether a first fault condition exists; and

12. The system of claim 11 wherein the method further comprises when the first fault condition exists, driving the switching circuitry open.

13. The system of claims 11 or 12 wherein the first fault condition comprises the battery cell having a voltage above a high voltage threshold.

14. The system of claims 11 or 12 further comprising a starter interlock communicatively coupled to the processor and electrically coupled in series with the ignition switch, and wherein the method further comprises:

(a) determining whether a second fault condition exists; and

15. The system of claim 14 wherein the method further comprises when the second fault condition exists, opening the starter interlock.

16. The system of claims 14 or 15 wherein the second fault condition comprises the battery cell having a voltage below a low voltage threshold.

17. The system of claims 14 or 15 wherein the fault condition is selected from the group comprising whether the battery cell is below a low voltage threshold, whether the battery cell equals or exceeds the high voltage threshold, whether the battery cell has a temperature equal to or less than a low temperature threshold, whether the battery cell has a temperature equaling or exceeding a high temperature threshold, and whether a key is in an ignition that comprises the ignition switch.

18. The system of claim 17 wherein the fault conditions are identical to each other.

19. A method for charging a starter battery, the method comprising:

(a) determining whether a first fault condition exists; and

(b) charging the starter battery when the first fault condition does not exist, wherein the starter battery comprises:

(i) a battery cell comprising a positive terminal and a negative terminal;

(ii) a starter terminal and a hotel terminal electrically coupled in parallel to the positive terminal of the battery cell; and

(iii) a negative terminal electrically coupled to the negative terminal of the battery cell, and wherein the starter battery is charged only via the hotel terminal.

20. The method of claim 19 wherein the method further comprises when the first fault condition exists, preventing the starter battery from being charged by driving open switching circuitry, the switching circuitry electrically coupled between the hotel terminal and the positive terminal of the battery cell.

21. The method of claims 19 or 20 wherein the first fault condition comprises the battery cell having a voltage above a high voltage threshold.

22. The method of claims 19 or 20 further comprising: (a) determining whether a second fault condition exists; and

(b) when the second fault condition does not exist, powering a starter motor only via the starter terminal.

23. The method of claim 22 wherein the method further comprises when the second fault condition exists, preventing the starter battery from powering the starter motor by opening a starter interlock.

24. The method of claims 22 or 23 wherein the second fault condition comprises the battery cell having a voltage below a low voltage threshold.

25. The method of claims 22 or 23 wherein the fault condition is selected from the group comprising whether the battery cell is below a low voltage threshold, whether the battery cell equals or exceeds the high voltage threshold, whether the battery cell has a temperature equal to or less than a low temperature threshold, whether the battery cell has a temperature equaling or exceeding a high temperature threshold, and whether a key is in an ignition of a vehicle powered by the starter battery.

26. The method of claim 25 wherein the fault conditions are identical to each other.

27. A non-transitory computer readable medium having encoded thereon instructions to cause a processor to perform a method for charging a starter battery, the method comprising:

(a) determining whether a first fault condition exists; and

(i) a battery cell comprising a positive terminal and a negative terminal; (ii) a starter terminal and a hotel terminal electrically coupled in parallel to the positive terminal of the battery cell; and