Battery maintenance system

A battery-powered vehicle and a vehicle battery maintenance system that includes a battery charger that monitors energy consumption data from the vehicle battery to generate charging instructions to a charger. A central data unit (CDU) can determine whether if a vehicle electrical load is consuming too much energy and then generate instructions to the vehicle controller to limit the energy consumption. The CDU can notify an offsite central computer if the battery has not been charged according to charging instructions.

FIELD

The present invention relates to a battery maintenance system for battery-powered vehicles.

BACKGROUND

Battery-powered vehicles are often used by businesses. Common industrial vehicles include materials handling vehicles (such as lifting or pallet vehicles), cleaning vehicles (such as scrubbing or sweeping vehicles) and even recreational vehicles (such as golf carts). Sometimes battery-powered vehicles are used in fleets, wherein a large number of vehicles are maintained by a single business. Also, sometimes vehicles within the single fleet have different rechargeable battery technologies (such as lead-acid, lithium-ion, sealed, flooded or deep cycle batteries).

Different battery technologies use different charging methodologies or algorithms. Battery chargers are provided that are designed to charge a specific type of battery. As such, several different battery chargers are often needed to charge different vehicles within a fleet. This can be cumbersome and lead to operator errors. For example, an operator typically uses the battery-powered vehicle to complete a task and thereafter connects the vehicle battery to a specified battery charger. However, sometimes an operator forgets to connect the battery to its charger or even connects the battery to a wrong charger type or to a malfunctioning charger. Operators might also interrupt the charge prematurely, resulting in undercharging. Or, a charger may misjudge the amount of energy required to fully recharge the battery, possibly resulting in an overcharge or undercharged battery. Such errors obviously negatively impact the life of the vehicle battery. Additionally, operators need to invest time in battery maintenance.

As one might expect, battery replacement on battery-powered vehicles is very expensive. To the extent one can protect and extend the life of a battery, the cost savings can be significant. Additionally, it is desirable to reduce the amount of maintenance an operator needs to spend on vehicle batteries.

SUMMARY

Certain embodiments of the invention include a battery powered vehicle with a vehicle battery, a battery charger, a vehicle electrical load, and a central data unit (CDU). The battery charger is capable of charging batteries of differing chemistries, the CDU is in communication with the battery, the charger, and the electrical load. The CDU receives battery identification data, including the chemistry type of the battery. The CDU also receives energy consumption data from the battery and uses the battery identification data and energy consumption data to generate charging instructions for the charger, and outputs the charging instructions to the battery charger.

Some embodiments of the invention provide a vehicle battery maintenance system that includes a battery charger, and a central data unit (CDU), where the CDU is in communication with the charger and is configured to gather data from an existing vehicle battery and an existing vehicle electrical load. The CDU also collects energy consumption data from the battery, maintains a clock and a calendar, and creates an energy consumption profile for the vehicle. The CDU creates the profile by tracking the energy consumption data over a period of vehicle use, the timing of the use, and the date of the vehicle use. The CDU predicts the amount of energy needed by the battery during a subsequent vehicle use based on the profile. The CDU uses the energy consumption data and the prediction in order to generate charging instructions for the charger. The CDU also outputs the charging instructions to the charger.

Some embodiments of the invention include a battery-powered vehicle that generates instructions to a controller of the vehicle in order to limit the energy consumption by the vehicle electrical load if the vehicle electrical load is consuming too much energy. Some embodiments of the invention provide a vehicle battery maintenance system where the CDU notifies an offsite central computer if the battery has not been charged following the charging instructions. Some embodiments of the invention provide a vehicle battery maintenance system where the CDU or the offsite central computer determine the charge capacity remaining in the vehicle battery based on energy consumption data and the charging instructions.

DETAILED DESCRIPTION

For the purpose of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawing and specific language will be used to describe the same. It will, nevertheless, be understood that no limitation of the scope of the invention is thereby intended; any alterations and further modifications of the described or illustrated embodiments, and any further applications of the principles of the invention as illustrated therein, are contemplated as would normally occur to one skilled in the art to which the invention relates.

An intelligent battery maintenance system100for battery-powered vehicles is provided.FIG. 1illustrates a battery maintenance system100in accordance with certain embodiments. The system100includes a battery-powered vehicle50. The vehicle50can be any battery-powered vehicle known in the art. In certain cases, the vehicle50is part of a fleet of vehicles. The vehicle50can also be a vehicle that is used at consistent periodic intervals approximating a relatively consistent usage pattern (e.g., set times everyday, every other day, once a week or even every other week). In certain cases, the vehicle50is a commercial vehicle, such as a floor scrubbing vehicle, a floor sweeping vehicle, a vacuuming vehicle, or a combination thereof. The maintenance system100includes a battery1, a central data unit3, and vehicle electrical loads4, all located on the vehicle. The electrical loads4include several components, such as a motor6, a motor controller5, a water pump/reservoir10, and a vehicle display8. Also, the battery1can include an identifier9. The charging system100also includes an off-board battery charger2and a central computer7. Each of these components will now be described in more detail.

FIG. 1illustrates the communications between various components in the battery maintenance system100. The central data unit (CDU)3is in communication with the vehicle battery1, battery charger2, vehicle controller5, computer7, display8, battery identifier9and water pump/reservoir10. In addition, CDU3, which can include a real-time clock, connects to the connection between the battery charger2and the battery1in order to monitor the energy delivered to the battery1by battery charger2. CDU3also connects to the connection between the battery1and the vehicle electrical loads4to monitor the energy drawn from the battery1by the vehicle electrical loads4. The CDU3inputs and/or outputs information to each of these components. The CDU3can be in communication with these components using a variety of known communication setups, including known wired or wireless communication architectures.

The vehicle battery1can include any known rechargeable vehicle battery in the art. In some cases, the battery1is a lead-acid battery or a nickel metal hydride (NiMH) battery. In other cases, the battery1is lithium-ion (Li-ion) battery. The battery1also includes an identifier9. The identifier9stores information about the battery1. In some cases, the identifier9is an RFID tag that stores battery identification data. Battery identification data may include, but is not limited to, battery type, battery chemistry type, battery serial number, battery manufacture date, battery size, battery technology and the like. The battery1is also in communication with the battery charger2and the vehicle electrical loads4. In other words, the battery1receives energy from the charger2and delivers energy to the electrical loads4. As shown inFIG. 1, the CDU3taps in to each of these links between the charger2and the battery1and between the battery1and the electrical loads4so that the CDU monitors the energy delivered to the battery and discharged from the battery. The CDU3stores this data in the form of energy consumption data. In many cases, the CDU3continuously receives this data in real time or it samples, for instance the voltage and current out, periodically. By tracking energy consumption data over time, the CDU3may then create an energy consumption profile for the vehicle that includes more than just basic energy consumption. An energy consumption profile may include parameters such as average number of Amp-Hours per charge, peak number of Amp-Hours per charge, average voltage of the Battery1at the completion of vehicle use, lowest remaining Battery1voltage at the completion of vehicle use after a period of several days of use, time of discharge, rate of discharge over time, maximum, minimum, and average period of vehicle use per day, maximum, minimum, and average period of electrical load4use (e.g., one or more of the vehicle electrical components) per day, start and end times for usage and charging, days of the week or the month for vehicle usage and charging, and the like. In embodiments where the vehicle is a commercial scrubber, one or more of the vehicle electrical components stored in the energy consumption profile may include the vehicle scrubber. Similarly, where the vehicle is a commercial scrubber, one or more of the vehicle electrical components stored in the energy consumption profile may include the vehicle scrubber. Thus, the energy consumption profile, in such cases, may include the maximum, minimum, and average period of use of the vehicle scrubber or the vehicle sweeper. As will be noted below, the energy consumption profile provides an indicator or predictor of future energy consumption that may be used to control the amount of charge to deliver to the battery1during recharging.

Thus, CDU3receives the battery identification data and the energy consumption data. The vehicle50also includes electrical loads4. In many embodiments, the electrical loads4include at least a vehicle controller5and a vehicle motor6. The controller5is in connection with and operates the motor6. The vehicle controller5can include any vehicle machine controller known in the art. Likewise, the vehicle motor6can include any motor type known in the art that uses electricity. The controller5responds to commands from the operator to control the motor6. For example, the controller5can respond to brake commands from a brake actuator or accelerator commands from an accelerator actuator. In certain embodiments of the present invention, the controller5also responds to instructions from the CDU3, as will be explained in more detail below.

The vehicle50may also include a display8. The display8, which may be considered as another vehicle electric load4, can be provided anywhere about the vehicle50. The display8can be any display type known in the art such as an LCD display, touch-screen display or other suitable display. The display8can also include user-interface buttons to allow an operator to navigate menu options presented thereon. The display8displays information related to the vehicle battery1, for example the percent charged, run time remaining before discharged (based on charge level and rate of discharge monitored by CDU3), battery type, remaining estimated lifespan of the battery, battery watering information, battery malfunctions, remaining time until battery charging is complete (based on charge level, rate of charge, and desired charge level monitored and calculated by CDU3) and the like. The display8can also display information related to the vehicle operation, for example the on/off status of the vehicle, current vehicle energy consumption information, remaining operating time based on the battery charge level, and the like.

In certain embodiments, the vehicle50also includes a water pump/reservoir10. Certain battery types require watering. For example, lead-acid batteries come in two common types: flooded lead-acid batteries and sealed lead-acid batteries. Flooded lead-acid batteries require watering after use but sealed lead-acid batteries do not. The water pump/reservoir10is provided to water the battery1if needed. The water pump/reservoir10includes a reservoir that contains water and opening for an operator to fill the reservoir with water, among other things.

The battery charger2can be either on-board or off-board the vehicle50. InFIG. 1, the charger2is shown off-board. In any event, the battery charger2is in communication with the CDU3. In certain embodiments, the battery charger2is a battery charger that is configured to charge several different types of batteries and batteries of different types of chemistries (e.g., lead-acid or Li-ion). The charger2is also programmable so that it can receive instructions from the CDU3and adjust its charging algorithm and charge profile based on those instructions. The optional offsite central computer7is off-board the vehicle but may also be in communication with the CDU3.

The battery maintenance system100is designed to extend the useful life of the battery1and to reduce the amount of operator maintenance needed.FIG. 2illustrates an operation mechanism200for the system100according to certain embodiments. Once an operator is done using the vehicle50, he or she connects the vehicle battery1with the battery charger2(step210). Typically, the vehicle battery1is connected to an electrical cord with a plug that can be plugged into the charger2, although several arrangements of connecting the battery1to the battery charger2can be used.

This connection automatically prompts the CDU3to input battery identification data from the battery identifier9and energy consumption data from the connections between the battery1and the battery charger2and the vehicle electrical loads4(step215). The CDU3then uses the inputted data to generate charge instructions for the battery charger2. The CDU3can consider a number of factors when generating charging instructions, which may also be considered as a charging profile, such as battery type, chemistry, manufacture date, size, technology, voltage, charge status, discharge from previous vehicle use, number of charge cycles undergone, date of last battery equalization charge, and the like. The charging instructions can include instructions on the level of charge, rate of charging, time of charging, days of week for charging, and date of charging. The time, days of week, and dates may be tracked by an on-board clock and calendar within CDU3. In many cases, the charging instructions can also include charging algorithms. Particular charging algorithms are used by different types (e.g., chemistries, manufacturers, models, etc.) of batteries. Thus, the CDU3may specify which type of charging algorithms to employ based on the type of battery1provided by the identifier9. In addition, CDU3may also specify modifications to the charge algorithms based on recent energy consumption data and/or the energy consumption profile for the battery1. For instance, if recent energy consumption data indicates that only a small amount of charge has been consumed from battery1since its last charge, then CDU3may specify to charger2to eliminate certain phases from the charge algorithm (e.g., the early phases of the charge algorithm) since a large amount of additional charge is not needed. Such algorithm modification may extend the life of the battery1since battery1need not endure the entire charge algorithm in order to complete its charging. In this way, not only can CDU3instruct the charger2of the amount of charge to return to battery1, but CDU3can also instruct charger2to specifically modify known charge algorithms based on recent energy consumption data and/or energy consumption profiles developed over time. The charge profile (instructions) are therefore tailored to the energy consumption data or the energy consumption profile, which can extend the useful life of the battery1. The charging instructions may also include whether to conduct an equalization charge. The on-board clock and calendar can be used to estimate energy need and the calendar can be used to optimize cell balancing.

The CDU3may also be in communication with the offsite computer7. New or updated charging algorithms can be periodically sent from the computer7to the CDU3. For example, new charge algorithms are created, the central computer7can send new algorithms to the CDU3to consider when generating charging instructions3. CDU3can then upgrade the charger2with the new algorithms the next time the charger2is connected. In some cases, each time the operator connects the vehicle battery1with the battery charger2(step210), the CDU3also checks in with the computer7to determines whether its charging algorithms need to be updated.

When generating charging instructions (aka charge profile), the CDU3also determines whether the battery1is a lithium-ion, flooded, or sealed Lead Acid battery (step220). If the battery1is not a lithium-ion battery, the CDU3generates charging instructions for the non lithium-ion battery (step240). In certain cases, the charging instructions for a non lithium-ion battery will simply be instructions to charge the battery1to its full charging capacity and to maintain the battery1at the full charging capacity until the next vehicle use. However, if the battery1is a Li-ion battery, the CDU3generates charging instructions for a lithium-ion battery (step230). The charging instructions for a lithium-ion battery will typically be more complex and is explained in more detail below.

The ability of the CDU3to generate different charging instructions for a lithium-ion battery and a non lithium-ion battery is advantageous because maximum life on a typical non lithium-ion battery is achieved if the battery is kept at its full charge whereas a lithium-ion battery is the opposite. A lithium-ion battery has a maximum life when its charge is kept at a minimum level required to complete a task. As such, it is desirable to only charge the battery1to the minimum level required to complete a task and also to keep the battery1at a reduced charge until it needs to be used.

With previous charging systems, an operator simply connects a vehicle battery to a charger after vehicle use and the battery remains connected to the charger until it is used for a future task. As such, the battery is stored in a fully charged state with little or no load. Under such storage conditions, a lithium-ion battery chemistry degrades. Also, existing charging systems are often designed to recharge the battery as quickly as possible to reduce the amount of time a user may have to wait to use the vehicle again. Charging a lithium-ion battery too quickly raises the temperature of the battery, which may also lead to degradation in battery chemistry. Thus, while past charging mechanisms are often acceptable for a non lithium-ion battery, they are less than ideal for a lithium-ion battery.

With a lithium-ion battery, under certain embodiments of the invention, it is desirable to wait to charge the battery until immediately before vehicle use. As such, in the current system100, if the CDU3determines the battery1is a lithium-ion battery (step220), it also determines when it is desirable to begin charging the battery1and prompts the battery charger2to begin charging the battery1once a set time point occurs (step235). The CDU3uses energy consumption profiles gathered during periods of use to predict future periods of use and non-use of the vehicle and generate a set time point of when to start charging the battery1so it is ready for the next vehicle use. In some cases, the CDU3tracks previous periods of use, length of use, time of use, days of the week of use and the like when forming an energy consumption profile. For example, some vehicles are used every day, every other day, once a week or even every other week. The CDU3uses all of this information to generate a set time point for inclusion in its charge profile that is delivered to the charger2.

An example will now be described. Say the vehicle50is generally used between 1:00 AM and 4:00 AM but is idle for the remainder of the day. Once an operator finishes using the vehicle50at 4:00 AM, he or she connects the battery1to the battery charger2. Under traditional charging systems, the charger2immediately begins charging the battery1until its charging is deemed complete. The charger2initiates charging immediately regardless of the battery type. Under certain embodiments of the current system100, the CDU3uses energy consumption profiles developed over a period of time to generate an optimum set time point. If the CDU3determines that it takes approximately three hours to charge the battery1, it may prompt the battery charger2to start charging the battery1at 9:00 PM—a set time point—so the battery1will be finished charging just before the expected usage time. This allows the battery1to remain at a lower charge capacity for the remainder of the day—from 4:00 AM to 9:00 PM. Also, when determining an amount of time needed to charge the battery1, the CDU3can also allow sufficient time to assure that the charge rate is slow enough to prevent the battery1from reaching a temperature where chemical damage to the battery1will occur. The process can occur with no operator or manager input. The operation may be totally transparent to the operator yet can yield significant improvements in battery life.

During periods of non-use, the CDU3can also reduce the lithium-ion battery charge to an optimum level for storage. For example, if the CDU3determines a long period of inactivity is expected, it may instruct the charger2to discharge the battery1to the desired level of charge. The CDU3can also control the rate of discharge to prevent a discharge rate that causes a rise in the temperature of the battery1that would cause chemical damage to the battery1. Thus, the battery charging system100optimizes the useful life of the lithium-ion battery by maintaining the battery charge at a level optimum for storage while having the battery1ready for use when required by the operator.

Once the CDU3generates charging instructions, it outputs those instructions to the charger2(step245). The charger2then charges the battery1(step250) until charging is complete (step255). During charging, the CDU3continues to receive energy consumption data from the battery connections. The CDU3can use this data to generate and send instructions to the offsite computer7and/or display8to display status information on the battery charging, such as the percent of battery charged, remaining time left to complete charging, and the like. The CDU3can also use this data to determine whether a fault in the charging occurs. If a fault occurs, the CDU3sends instructions to the offsite computer7and/or display8to alert the operator that a fault has occurred. Such alerts may also include notices that the operator did not remember to charge the battery1.

The maintenance system100also incorporates a battery watering system in some embodiments. After charging is complete, the CDU3uses battery identification data (step215) to determine whether the battery1is a flooded battery type that requires watering (step260). If the battery1is not a flooded battery, the CDU3outputs instructions to the offsite computer7and/or display8to alert an operator that the vehicle is ready for use (step280). If the battery1is a flooded battery, the CDU3generates watering instructions for watering the battery1(step265) and then outputs those instructions to the water pump/reservoir10(step270). In some cases, the CDU3also determines when it is desirable to begin watering the battery1and prompts the pump to begin watering the battery1once a set time point occurs. The watering instructions can also be provided in the form of profiles. The water pump then waters the battery1(step275). Once watering is complete, the CDU3can output instructions to the offsite computer7and/or display8to alert an operator that the vehicle is ready for use (step280).

The battery watering system is advantageous because it even further reduces the amount of maintenance an operator needs to perform on the vehicle50. All an operator needs to do is make sure the water reservoir in the water pump/reservoir10is filled with water. The CDU3also monitors the water pump/reservoir10and determines whether water needs to be added, such as via a water level sensor known in the art. When water is needed, it sends instructions to the computer7and/or display8to alert the operator that water needs to be added to the water pump/reservoir10.

FIG. 3illustrates additional methods300of operation of the battery maintenance system100according to certain embodiments. When an operator desires to use the vehicle50, he or she turns the vehicle on (step305). This prompts the CDU3to select or load an energy consumption profile for the upcoming vehicle use (step310). The selected energy consumption profile can be based on an analysis of past energy consumption profiles. For instance, if the vehicle is used at about the same time each day, CDU3develops an energy consumption profile for each such expected use and selects an appropriate one based on several factors, including time of day of vehicle use.

As the operator uses the vehicle50, the CDU3continues to receive energy consumption data from the battery connections and operation data from the vehicle controller5. The energy consumption data can simply be the battery voltage, current and temperature in some cases. The CDU3uses this received information to determine whether the present energy consumption is too high for the vehicle to complete its expected use as predicted in the selected energy consumption profile (step320). If the present energy consumption is too high, the CDU3outputs operating instructions to the vehicle controller5instructing it to adjust the vehicle operating parameters to reduce battery charge consumption (step325). The specific vehicle parameter and the adjustment amount may be specified by the CDU3. The controller5then adjusts vehicle parameters to use less power and/or the controller5merely throttles down the vehicle parameters until the CDU3senses that the energy consumption has dropped to the expected amount or within a threshold level. In some embodiments, the controller chooses which vehicle parameters to throttle down following a list of priorities, from least important vehicle parameters to most important. In the case where the vehicle is a commercial floor scrubber, the energy consumption profile may correspond to an expected down-pressure of the scrubber brush or brushes that produces an expected load. To the extent a user sets the down-pressure at an amount higher than expected or too high for the vehicle to complete its expected task, the CDU3may instruct the vehicle controller5to decrease the down-pressure to the expected amount or to an amount that will permit the vehicle the complete its expected task without the battery1becoming fully discharged.

If the energy consumption is not too high, the CDU3outputs operating instructions to the controller5instructing it to maintain the current vehicle operating parameters or power levels (step330). Alternatively, in such a situation, the CDU3does not output any instructions to the controller5. This loop continues until the operator turns the vehicle off or the vehicle shuts off on its own (step335). This loop is advantageous in cases where a new operator uses a vehicle more aggressively or actively than a previous operator.

Once the vehicle is turned off (step335), the CDU3uses the energy consumption data inputted to determine whether the battery1is fully discharged (step340). If the answer is no, the CDU3uses inputted information to create an actual energy consumption profile and archives this profile (step355). This actual energy consumption profile contains information that enables the CDU3to elect future energy consumption profiles (step310) and to generate charging instructions for the charger2(step230or240), among other things. If the answer is yes, the CDU3uses received energy consumption data to determine whether the battery1has sufficient capacity for future vehicle use (step345). As part of this determination in step345, the CDU3may also determine whether the battery1is charged according to the charge instructions. That is, CDU3may check the voltage level of battery1to determine if it is within an acceptable range of the expected voltage following the intended charge. If the answer is no, the CDU3outputs instructions to the offsite central computer7and/or display8to alert the operator that the battery1needs to be replaced (step350). If the answer is yes, the CDU3creates an actual energy consumption profile (step355).

Finally, the CDU3outputs any and all energy consumption data and energy consumption profile information it has to the central offsite computer7. This allows for an operator to access this information and to review it, for example by using a software program resident on either the CDU3or on the central offsite computer7. The software program can use the information to generate a wealth of useful information to the operator, such as a predicted end of battery life (e.g., how many charge cycles remain in the battery, the date when the battery will need replacement based on the expected usage of the vehicle, whether the battery has sufficient charge capacity to power the expected uses of the vehicle), vehicle usage statistics, charger malfunction, maintenance reminders, alerts that the battery1was not charged, and the like. In situations where the software program determines that the battery has insufficient charge capacity to power expected uses of the vehicle, the software program may be used to determine if the battery has sufficient charge capacity for another deployment. Thus, the software program may calculate how many charge cycles remain that will provide the battery with sufficient capacity to handle the current task. For Lithium Ion Batteries (and other chemistries with relatively linear capacity loss), the software program may be used to determine other deployments, such as other vehicles, where less charge capacity is required. That is, the software program may assist a company in transferring its batteries to, for instance, other vehicles that have lower energy load requirements between each charge cycle. Such information may be used to extend the battery's useful life beyond a single deployment of the battery. The offsite computer can also be in communication with an operator's cell phone, PDA, personal computer or the like, so that alerts can be sent directly to the operator.

In the foregoing detailed description, the invention has been described with reference to specific embodiments. However, it can be appreciated that various modifications and changes can be made without departing from the scope of the invention.