Automatic battery watering system

An automatic and passive battery fluid maintenance system maintains the fluid levels in a battery system by replenishing water as the water is lost from the battery. A reservoir is used to contain a volume of fluid and is mounted above the batteries. Fluid from the reservoir flows into a distribution manifold through a flow regulator. From the manifold the fluid is distributed a vent plug at each battery. The vent plugs are configured to control create a backpressure in the fluid line when the battery fluid level is at an optimum level. As a result of the backpressure, fluid does not flow into the battery through the vent plug. When the fluid in the battery drops below the optimum level, the backpressure is reduced, allowing water to flow until the fluid level of the battery again is at the optimum level.

FIELD OF THE INVENTION

The present invention relates generally to battery systems that require replenishment of a fluid, and, more particularly, relates to a continuous fluid replenishment system that maintains battery fluid levels while the battery system is in use and while it is being recharged, where the fluid replenishment system travels with the battery and does not rely on float valves or other mechanical operation to provide fluid to the battery.

BACKGROUND OF THE INVENTION

Although electric vehicles for personal transportation are becoming increasingly popular, industrial vehicles have long been operated by electric battery systems. In particular, many types of fork lift vehicles are battery operated. Unlike electric vehicles made for personal transportation, which use lithium ion-based battery systems, many industrial vehicles use lead acid battery systems. There are a variety of reasons for this, not the least of which is that lead acid battery systems are substantially less expensive than newer battery systems. Industrial operations have an infrastructure based around lead acid battery systems, including charging and maintenance, which would need to be replaced in order to change over to a different battery system, which represents a substantial cost. In addition, it is known that a lithium ion battery system that provides similar energy storage capability as a lead acid battery system will be much lighter than the lead acid battery, and is some applications this is not a benefit. For example, a forklift depends on having a certain amount of weight to counter weight the load it is lifting. As such, lead acid battery systems are likely to persist in certain applications.

Lead acid batteries use aqueous cells and during use they can lose water. Batteries in the center of a battery array, for example, tend to get hotter than batteries on the outside of an array, and lose more water than those on the outside. Since the loss of water can impact the service life of a battery, it is necessary to ensure that the water is replenished before the fluid loss can result in damage to a battery. Typically, replenishment is done when a battery array is removed from a vehicle for charging. A technician will inspect each battery cell and determine if water is needed, and replenish those cells that need replenishing. This is a tedious task that is prone to error.

There have been attempts made to create self-watering battery systems, where a supply of water is provided, and a valve in each battery cell control the flow of water into the battery. In some self-watering systems, the battery cells are connected in a daisy chain where the first battery fluid level controls whether fluid will flow into the subsequently connected battery cells. These systems assume every battery cell in an array will lose the same amount of water, but in high-use systems this is not the case, and as a result, some battery cells will be properly replenished while subsequently connected battery cells continue to lose water because of higher operating temperatures in those particular battery cells. On the other hand, connecting the higher loss battery cells first in line can result in over-watering of subsequent battery cells. Other systems have sought to use float valves on each battery cell to control fluid flow into each battery cell. However, those systems have been found to be prone to error due to vibration, allowing excess water to flow past the float mechanism.

SUMMARY OF THE INVENTION

In accordance with some embodiments of the inventive disclosure, there is provided an automatic watering system for a battery or battery assembly that includes a fluid reservoir that has an outlet. There is also a flow regulator that has an inlet and an outlet. The inlet of the flow regulator is connected to the outlet of the reservoir. There is also a manifold that has a plurality of feed channels. Each feed channel has an outer end terminated at a connector and an inner end terminated at a common chamber. The flow regulator is connected to the manifold to provide water from the reservoir to the common chamber at a regulated rate. There is also at least one vent plug. Each vent plug has a head including a head channel through the head from an inlet to an exit at a bottom of the head. Each vent plug further includes an outer wall that extends from the bottom of the head. The outer wall defines an interior volume of the vent plug and there is a floor at a bottom of the outer wall. There is a vent hole formed through the floor. A bottom of the vent hole is positioned at an optimum fluid level height when the at least one vent plug is inserted into a vent opening of a battery. Each vent plug also has a column that includes a column channel that extends from the floor to the bottom of the head in the interior volume. A top of the column is positioned under the exit of the head channel. There is an opening defined between the top of the column and bottom of the head which fluidly connects the column channel to the interior volume. A bottom of the column channel extends below the bottom of the vent hole.

In accordance with a further feature, the flow regulator comprises a stem at a bottom of the reservoir, a boss extending from the stem and including a regulation chamber, a valve that is threadably engaged in the boss that regulates flow through the regulation chamber.

In accordance with a further feature, the flow regulator is connected in line between the reservoir and the manifold.

In accordance with a further feature, the manifold is planar and has a central feed point to a plurality of radial channels that extend outward from the central feed point.

In accordance with a further feature, the head channel includes a pinhole obstruction between the inlet and the outlet.

In accordance with some embodiments of the inventive disclosure, there is provided an automatic battery fluid maintenance system that includes a fluid reservoir having an outlet and a flow regulator having an inlet and an outlet. The inlet of the flow regulator is connected to the outlet of the reservoir. There is a manifold that has a plurality of feed channels, each feed channel has an outer end terminated at a connector and an inner end terminated at a common chamber. The flow regulator is connected to the manifold to provide water from the reservoir to the common chamber at a regulated rate. There is also at least one vent plug that is configured to fit into a vent opening of a battery. The vent plug having an inlet that is coupled to the manifold to receive water from the manifold, and wherein the vent plug is configured to create a backpressure that inhibits water from flowing into the battery when a fluid level of the battery is at an optimum level.

In accordance with a further feature, the vent plug includes a head having a head channel through the head from an inlet to an exit at a bottom of the head. The vent plug also includes an outer wall extending from a bottom of the head that defines an interior volume and having a floor at a bottom of the outer wall, a vent hole formed through the floor, wherein a bottom of the vent hole is positioned at an optimum fluid level height when the at least one vent plug is inserted into a vent opening of a battery. There is also a column having a column channel extending from the floor to the bottom of the head in the interior volume, a top of the column positioned under the exit of the head channel, an opening defined between the top of the column and bottom of the head which connects the column channel to the interior volume. The vent plug also includes a bottom of the column channel which extends below the bottom of the vent hole.

In accordance with a further feature, wherein there is a gap between a top of the column and a bottom of the head.

In accordance with a further feature, there is further a retaining ring formed around an outside of the outer wall.

In accordance with a further feature, the flow regulator comprises a stem at a bottom of the reservoir, a boss extending from the stem and including a regulation chamber, a valve that is threadably engaged in the boss that regulates flow through the regulation chamber.

In accordance with a further feature, the flow regulator is connected in line between the reservoir and the manifold.

In accordance with a further feature, the manifold is planar and has a central feed point to a plurality of radial channels that extend outward from the central feed point.

In accordance with a further feature, the head channel includes a pinhole obstruction between the inlet and the outlet.

In accordance with some embodiments of the inventive disclosure, there is provided an automatic battery watering system that includes a battery having a vent hole and a fluid level. There is a reservoir that has a volume which is filled with water or suitable aqueous battery fluid. There is a vent plug disposed in the vent hole of the battery. The vent plug has a head that has an inlet that is operably coupled to the reservoir such that water can flow from the reservoir to the inlet. The vent plug further has a body that includes an outer wall that extends from the head into the battery through the vent hole. There is an internal chamber defined within the body. The body has a floor which includes a vent opening therethrough. There is a channel that passes from the inlet to an outlet at a bottom of the head at the internal chamber, through the head. The floor is positioned at an optimum fluid level of the battery and when the fluid level of the battery is at the optimum fluid level a backpressure is created in the vent plug that inhibits the flow of fluid from the reservoir through the vent plug into the battery. When the fluid level of the battery is below the optimum level a lack of backpressure, due to the vent opening being exposed, allows flow of fluid into the battery through the vent plug from the reservoir.

In accordance with a further feature, the vent plug includes a head channel through the head from the inlet to an exit at the bottom of the head, a column having a column channel extending from the floor to the bottom of the head in the interior volume, a top of the column positioned under the exit of the head channel, an opening defined between the top of the column and bottom of the head which connects the column channel to the internal chamber defined by the outside wall, and a bottom of the column channel which extends below the bottom of the vent hole.

In accordance with a further feature, there is a gap between a top of the column and a bottom of the head.

In accordance with a further feature, there is further included a retaining ring formed around an outside of the outer wall.

In accordance with a further feature, the flow regulator comprises a stem at a bottom of the reservoir, a boss extending from the stem and including a regulation chamber, a valve that is threadably engaged in the boss that regulates flow through the regulation chamber.

In accordance with a further feature, the flow regulator is connected in line between the reservoir and the manifold.

In accordance with a further feature, the manifold is planar and has a central feed point to a plurality of radial channels that extend outward from the central feed point.

In accordance with some embodiments of the inventive disclosure, there is provided a vent plug for an automatic battery watering system that includes a head portion having a water inlet, and an internal volume bounded by a sidewall that extends downward from the head portion, and a floor at a bottom of the sidewall. There is also an extension that extends downward from the floor and has an opening to the internal volume. The floor includes an opening through the floor to the internal volume. The internal volume is sealed other than at the opening at the extension and the opening through the floor in order to create a backpressure in the internal volume when a fluid level of a battery covers the opening at the extension and the opening through the floor.

“In the description of the embodiments of the present invention, unless otherwise specified, azimuth or positional relationships indicated by terms such as “up”, “down”, “left”, “right”, “inside”, “outside”, “front”, “back”, “head”, “tail” and so on, are azimuth or positional relationships based on the drawings, which are only to facilitate description of the embodiments of the present invention and simplify the description, but not to indicate or imply that the devices or components must have a specific azimuth, or be constructed or operated in the specific azimuth, which thus cannot be understood as a limitation to the embodiments of the present invention. Furthermore, terms such as “first”, “second”, “third” and so on are only used for descriptive purposes, and cannot be construed as indicating or implying relative importance.

In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly defined and limited, terms such as “installed”, “coupled”, “connected” should be broadly interpreted, for example, it may be fixedly connected, or may be detachably connected, or integrally connected; it may be mechanically connected, or may be electrically connected; it may be directly connected, or may be indirectly connected via an intermediate medium. As used herein, the terms “about” or “approximately” apply to all numeric values, whether or not explicitly indicated. These terms generally refer to a range of numbers that one of skill in the art would consider equivalent to the recited values (i.e., having the same function or result). In many instances these terms may include numbers that are rounded to the nearest significant figure. In this document, the term “longitudinal” should be understood to mean in a direction corresponding to an elongated direction of the article being referenced. Those skilled in the art can understand the specific meanings of the above-mentioned terms in the embodiments of the present invention according to the specific circumstances.

DETAILED DESCRIPTION

The invention of the disclosed embodiments provides a novel and efficient automated battery watering system. The inventive watering system is completely passive and avoids the use of float valves. Once the watering system is set up for a given battery assembly, it can travel with the battery assembly and continuously provide water/fluid to the battery while the battery assembly is in use, while it is being charged, and while it is offline being neither used or charged.

FIG.1shows an automatic battery watering system100, in accordance with some embodiments. The system100provides for the watering of a one or more aqueous-based batteries, such as, for example, lead-acid batteries used for industrial equipment. As is known, for example, a forklift can be electrically powered using a lead-acid battery assembly, which includes several lead-acid batteries, each having a nominal voltage of about twelve volts. While in use, some of the batteries in the battery assembly will get warmer than surrounding batteries, simply due to their central location in the battery assembly. As a result, these batteries can lose water at a faster rate than batteries on the outside of the battery assembly. Thus, each battery in the battery assembly can have different replenishment requirements to maintain the battery at an optimal operating state.

Accordingly, the system100includes a fluid reservoir102that has a volume104. In some embodiments the volume104can be on the order of one to two liters. Fluid can be periodically added to the volume104as it becomes depleted over time. At the bottom of the reservoir102is an outlet106that is configured to accept an end of a section of tubing108over it. That is, the tubing108fits over a short cylindrical structure, the outlet106, as is well known. There is a channel through the outlet106that is fluidly connected to the volume104which allows fluid to pass from the volume104into the tubing108.

The section of tubing108is connected, at an opposite end, to an inlet112of an adjustable flow regulator110. The flow regulator110can be substantially similar to flow regulators used in the intravenous delivery of fluids to a patient in medical applications. There is a fixed portion118and a rotating portion116that can be rotated to select a flow rate. The flow regulator110has an outlet114that is connected to a second section of tubing120, and the flow rate beyond the outlet114is constrained by a setting of the flow regulator110. Being adjustable, the flow rate can be selected by a user/technician based on specific application parameters such as the number of batteries being watered.

The second section of tubing120is further connected to a manifold assembly122that is shown here on its side. The manifold assembly122has an inlet126and a plurality of outlets124. The outlets124can be capped or connected to another tubing section such as third tubing section130, which is connected to an outlet124at one end128and to a vent plug132at the opposite end. The manifold assembly122can include a common chamber to which each of a plurality of channels are connected, with each channel passing through a respective one of the outlets124. Thus, the manifold assembly122is responsible for fluid distribution to each of one or more vent plugs132. The vent plugs132each fit into the vent opening over a respective battery. Accordingly, certain portions of the vent plugs132are sized to fit into a vent opening of the battery and replace a vent cap that is provided with the battery. Each vent plug132can include a head134, a body136includes an outside wall that depends from the head134, and a retaining ring138. In general, the body136is hollow within the outside wall, and there is a channel that extends from an opening at the inlet412to the volume inside the body136through the head134. As will be shown and described in further detail, there is an insert140that includes a portion that resides inside the body136, a portion that closes the bottom of the body136, and a section that extends below the bottom of the of the body. The retaining ring138is a structure that creates an interference fit with the body of the battery in the vent opening so that the vent plug132can be inserted into the vent opening and retained therein, but also allow removal of the vent plug132from the vent opening. The internal structure of the vent plug132assists in regulation of water delivered to a battery in a way that maintain the fluid level of the battery at an optimum and consistent level without the use of floats or other mechanisms.

Thus, water flows from the reservoir102to each vent plug132as needed. A flow regular and manifold can be connected in line between the reservoir and the vent plug(s). By “in line” it is meant that fluid flows through the flow regulator and manifold from the reservoir to the vent plug(s).

FIG.2shows a top plan view of a water manifold200as part of a water manifold assembly122for distributing water to batteries in a battery watering system, in accordance with some embodiments. The manifold200includes a generally planar body201that is round or circular and flat/planar. Around the outside of the body201are a plurality of outlets202that extend radially outward like spokes. Each of the outlets has an outer end or tip204that can receive an end of a section of tubing or a cap214. There is a feed channel or radial channel in each outlet202that extends from an opening at the tip204to a common chamber206that can be centrally located in the body and allows fluid to fill the common chamber206and pass through each channel that is open. The channels have an inner end at the common chamber206and can be tapered, getting narrower towards the common chamber206. In some embodiments one of the outlets202can be used as an inlet to allow water into the common chamber, as indicated by arrow210. Water flows out of the outlets202in the direction of arrow212, for example, as needed by each battery, and as regulated by the vent plug in the respective battery. Alternatively, to using one of the outlets202as an inlet, the manifold200can have an attachment feature208that allows connection of an inlet structure that includes a tip to receive an end of a section of tubing like tip204. The caps214fit snugly over the tip204of an outlet202and form a fluid seal to prevent egress of fluid at the respective outlet202on which the cap214is attached.

FIG.3is a perspective view of a water manifold assembly122with connections to batteries as a use example, in accordance with some embodiments. The manifold assembly includes the water manifold200with the circular planar body201which distributes water radially to each of a plurality of tips204. For example, a water supply line in the form of tubing section120can be connected to a coupler302at a central feed point that is attached at the attachment feature208to provide water from the tube section120to the common chamber206. One of the outlets202can be coupled to tubing section130, which is further attached to a vent plug132. Other outlets202which are not being used to supply water to a battery vent cap, can be capped using a cap214.

The manifold assembly122can further include a housing comprised of an upper housing portion304and a lower housing portion306. The upper housing portion304is disposed over the manifold200at a top side of the manifold200. The top side is the planar side to which the coupler is connected. The lower housing portion306is positioned under the manifold200opposite the upper housing portion304. The upper and lower housing portions304,306are likewise circular and planar, and encase the manifold200, sandwiching the manifold200between the upper and lower housing portions304,306. Each of the housing portions304,306have a plurality of radially oriented ridges312,314that are separated by semi-cylindrical grooves308,310. The grooves308,310are sized to allow the outlets202to extends along a cylindrical channel formed by the grooves310,312when the housing portions304,306are brought together, with room to further receive the end of a tubing section that is fit over the outlet202. The ridges312,314make contact and allow the housing portions304,306to be joined together, such as by welding or by adhesive. Like the grooves308,310, the ridges312,314extend to the outer edge in radial direction from the center of the respective housing portion304,306. However, they do not extend to the center, leaving room for the body201of the manifold200. In some embodiments there can be openings through the ridge312,314through which a fastener316, such as a cable tie, screw, bolt, or other fastener can pass to hold the housing portions304,306together, and/or hold the manifold assembly122to a mounting location. The upper housing portion314can include a feed boss318through which the feed tubing section120can pass to connect to the manifold200. The feed boss protects the feed connector320that the feed tube120is connected to.

FIG.4shows an exploded view of a vent plug that is configured to replace a battery vent cap and provide water to the battery, in accordance with some embodiments. The vent plug132is shown formed here in two parts, but any of a number of sub-assemblies could be realized within the spirit and scope of the disclosure. As shown here, the vent plug includes a plug section400and an insert section140which is inserted into the plug section as shown inFIG.5. The plug section400includes a head134, a body136having an outer wall that extends from a bottom414of the head134. The body136has a bottom408that is open, and the outer wall that forms the body136defines a volume bounded by the outer wall and the bottom414of the head134. The retaining ring138can include ramp portions416that allow for easier insertion and extraction of the vent plug from a vent opening in a battery. The retaining ring extends outward relative to the outer surface of the outer wall of the body136. Thus, the body136has an outer diameter or size that allows it to pass through a battery vent opening, while the diameter of the retaining ring138is such that it comes into contact with the wall of the battery housing around the vent opening and creates friction that resists movement of the vent plug. This friction prevents the vent plug from coming loose or inadvertently coming out of the vent opening, but is not so tight as to prevent manual extraction of the vent plug from the vent opening.

The insert section140is intended to be inserted into the body136of the plug section400, and includes a column406that is hollow and open at both the top420and bottom422of the column406. There is a first annular disk portion402that forms a floor of the vent plug132around the column406that is configured to bear against and seal to the bottom408of the body136. A second annular disk portion404is formed above the first annular disk portion402and around the column406. The second annular disk portion does not extend outward from the column406as far as the first annular disk portion404, creating a step410. The second annular disk portion404has an outer diameter that is about the same as the inner diameter of the outer wall of the body136of the plug section400. The column has a lower section424that extends below the annular disk portions402,404. When the insert section140is inserted into the body136of the plug section400, the top420of the column406is spaced apart from the bottom of the head134inside the body136. As shown inFIG.5, by arrow502, the insert section140is inserted into the plug section400such that a major portion of the column406is inside the body136. The first and second annular disk portions402,404can be thought of as one annular disk portion with a step410that allows one portion to be inside the body136of the plug section400.

FIG.6shows a bottom view of the insert section140, looking in the direction of arrow504ofFIG.5. In view here are the bottom surface of the first annular disk portion402, and the bottom422of the lower section424of the column406. The bottom422of the column406defines an opening to a channel604through the column, which is open at the top as well. The channel604has a diameter608that can be on the order of 0.1 to 0.5 inches in some embodiments, or larger or smaller in other embodiments. There is also a smaller channel602through the annular disk portions that has a diameter of about 0.005 inches with a tolerance of ten percent.

FIG.7shows a side cut-away view of a vent plug taken along section line AA ofFIG.4, in accordance with some embodiments. In this view it can be seen that there is a head channel comprised of a first channel702that leads from an opening712at the inlet412to a second channel705that has an exit that is an opening at the bottom708of head134inside the body136. The opening of the second channel705at the bottom708of the head134is positioned over the opening at the top420of the column406of the insert section140. There is a pinhole opening714from the first channel702to the second channel705which provides an obstruction that helps inhibit the flow of fluid in the presence of back pressure in the vent plug. Water passing through the first channel702to the second channel can into the channel604of the column406and into the fluid in the battery (assuming the vent plug is in a vent opening) in the absence of back pressure. There is a gap704between the top420of the column and the bottom708of the head in the body136. The gap704can be on the order of 0.01 inches. As can be seen, there is an internal chamber or volume706around the column406inside the body136, and there is a column chamber or column volume or column channel710inside the column406of the channel604. These two volumes706,710are connected through the gap704. The chambers706,710are volumes that are largely with air, except for the wall of column406.

FIGS.8A-8Ceach show a side cut-away view of a vent plug disposed in a battery as the fluid level in the battery rises, in accordance with some embodiments. In each ofFIGS.8A-8Cthere is a battery housing802which is the top of the battery. The vent plug132is positioned in a vent opening through the housing802. There is a tubing section130connected to the inlet412to deliver water to the vent plug132from the manifold assembly122. Inside the battery is a fluid804which can be the electrolyte that allows electrical flow between the plates of the battery. The fluid has a surface806which indicates the fluid level in the battery. InFIG.8A, the fluid level is below the bottom422of the column of the insert portion, resulting in no back pressure inside the vent plug132. As a result, water freely flows into the battery as indicated by arrow810. It is also shown there that there is a height808at which the bottom of channel602is above the bottom422of the column. InFIG.8Benough water has been provided to the fluid804to cause the fluid level to rise to the bottom422of the column. As a result, air or other gases inside the volume of the body136can escape through channel602, but not at the bottom422of the column. At this point, the water flow through the plug slows down due to increased back pressure. In order for water to flow into the vent cap132, it must displace air inside the vent plug132. That is, air and gasses inside the body136must be pushed out of the body136in order for water to flow into the vent plug132. InFIGS.8A and8Bgasses can escape freely inFIG.8Aout through the bottom of the channel604, and inFIG.8Bthrough channel602. As a result, there is a lack of backpressure in the internal volume of the vent plug, and fluid can flow into the vent plug.

InFIG.8Cthe fluid level has risen to cover the bottom of the channel602, and thus there is nowhere for air/gas to escape, resulting in backpressure that inhibits water flowing through the vent plug. At this point water flowing into the vent plug stops and the fluid level of the battery fluid804is at an optimum level. Accordingly, the dimensions of the vent plug are such that the bottom of channel602is positioned at the height of the optimum fluid level for the battery. In experiments conducted using the dimensions of the channels702,602, the diameter of the tubing, the height of the reservoir over the battery, and the flow rate selected at the flow regulator were found such that the fluid levels of several batteries could be maintained independent of each other at optimum levels. Minimizing the inside diameter of the tubing used in the system prevents the collection of a mass of water in the tubing that can create a forward pressure that overcomes the back pressure created by channels602,602being closed off by fluid in the battery. The tubing can have a nominal inner diameter of 0.125 inches in the sections shown herein. Other size tubing can be used, however, based on the application. It will be appreciated that the internal volume of the vent plug is sealed so that air/gasses can only escape through the bottom604of the extension of the insert, and through the opening602. Once those are covered by the battery fluid level there is no way for air/gas inside the vent plug to escape, which creates back pressure that inhibits further water from entering the vent plug through the tubing.

FIG.9shows a battery assembly900using an automated battery watering system, in accordance with some embodiments. There is a reservoir102that is fluidically coupled to a flow regulator110through a first section of tubing120. The flow regulator110is fluidically coupled to a manifold assembly122by a second section of tubing130. The call-out908shows the flow regulator110in more detail. There are nine batteries902shown, each battery having electrodes904,906. A vent plug132is shown inserted into the vent opening of each battery, and each vent plug132is fluidically coupled to the manifold through a section of tubing130. The nine batteries902form the battery assembly900which can be used to power, for example, a forklift.

FIG.10show use1000of an automated battery watering system with a battery assembly900of a forklift1002, in accordance with some embodiments. The forklift1002includes a space where the battery assembly900is housed and connected to the controls and motors of the forklift1002. A reservoir102can be hung on the forklift above the flow regulator110, and both of which are above the battery assembly900. The battery assembly900can be removed from the forklift for charging, and a different battery assembly can be placed in the forklift for continued operation of the forklift. When the battery assembly is removed, the reservoir102, flow regulator110, tubing, and manifold all travel with the battery assembly, and maintain the fluid levels of each battery in the battery assembly while the battery assembly is being charged, as well as when the battery assembly is finished charging and in queue to be placed into another forklift.

FIG.11shows an elevational side view of an installed reservoir1102for use in an automated battery watering system1100, in accordance with some embodiments of the invention. The reservoir1102is shown mounted on a steel pillar1104, such as a pillar of a forklift around the operator's compartment. A pair of straps1106can pass round the pillar1104and the reservoir1102, through loops1108on the side of the reservoir1102, to hold the reservoir1102in place. Further, the reservoir1102can includes magnet holder1116that holds one or more magnets1118that are fixed to the magnet holder1116. The magnets1118can produce a magnetic attractive force to the pillar1104that is strong enough to hold the reservoir1102in place and the straps1106are used to ensure the reservoir1102stays in place on the pillar1104in the event of an inadvertent impact or such.

The reservoir1102has an internal volume for holding a volume of fluid that is dispensed to batteries in order to keep the fluid level of the batteries at an optimum operating level. A top1110of the reservoir1102can be threaded to receive a cap1114to contain the fluid in the reservoir1102and to allow for periodic replenishment of the fluid. At the bottom of the reservoir1102there is a stem1120that extends downward and houses a flow regulator than can replace an in-line flow regulator such as flow regulator110. There is a channel through the stem1120that is fluidly coupled to the volume of the reservoir1102. A regulation chamber1130is formed in the stem1120in correspondence with a boss1122which extends horizontally. The boss1122is configured to receive and hold a regulator valve1124which threads into the boss1122. Once positioned in the boss1122, the valve1124can be turned to a desired position to adjust the flow of fluid through the stem1120to a tube1136, which fits over outlet1138, that is coupled to a distribution manifold assembly (e.g.,122). The valve1124has a tapered portion1128coupled to a threaded shaft1126. The threads on the threaded shaft fit into thread on the inside of the boss1122. A knob1134assists in turning the valve1124to the desired position. The tapered portion is separated from the threaded shaft1126by a seal1132. The regulation chamber1130can have a shape that is the same as the tapered portion1128. If the valve1124is turned to fully insert the threaded portion1128into the regulation chamber, then the threaded portion will contact the wall of the regulation chamber1130and prevent the flow of fluid into the tube1136. By turning the knob1134to back the tapered portion1128out from the regulation chamber1130there is increasing space, and hence increasing flow of fluid past the tapered portion1128from the reservoir1102into the tube1136.

FIG.12shows a side cut-away view of a vent plug1200, with the section view taken centrally along a vertical plane, in accordance with some embodiments. The vent plug1200is similar to that ofFIGS.7-8Cbut includes in internal stem1216that extends downward from the head1202inside the volume1224inside the outer wall1222. The stem1216fits inside the internal space1220of the column1212of the insert. There is a small gap on the order of thousands of an inch (e.g., 0.001″-0.010″+/−50%) between the inner surface of the column1218and the outer surface of the stem1216. This allows air to pass between the stem1216and the column1218.

In the head1202there is an inlet1204configured to receive the end of tubing section1206through which water is provided to the vent plug1200from the manifold. A horizontal channel1208in the inlet section connects to a vertical channel1210that continues from the head portion to the stem1216. The horizontal channel narrows to an opening1214between the horizontal channel1208and the vertical channel1210. The opening1214can have a diameter on the order of 0.010 inches with a tolerance of ten percent in some embodiments, although the opening1214can be larger or smaller. At the bottom of the insert is a floor1226that meets the bottom of the outer wall1222, and which can be joined to the bottom of the outer wall such as by welding. An opening1228passes though the floor1226(which is an annular disk portion). The opening1228can have a diameter of about 0.005 inches, with a tolerance of ten percent. An extension1230of the insert extends down from the floor1226.

Accordingly, the inventive automated battery watering system provides the benefits of simplicity while avoiding the problems associated with the prior art. Because the system doesn't use a “daisy chain” arrangement, each of the batteries are independently maintained. By avoiding the use of float valves, the batteries are not overwatered due to vibrations that allow water to flow past the float. There are no moving parts in the system that can fail. Once the system is set up and calibrated for the particular application, as long as the reservoir is suitably replenished, the batteries are maintained at their optimum fluid level. The system carefully controls the diameter or dimensions of the watering system including the water passages and the air escape openings to control the back pressure in the system relative to the fluid level in the battery. When the battery fluid level is low, there is very little to no back pressure as the extension at the bottom of the insert of the vent plug is open to air. When the fluid level rises to cover the bottom of the extension, then air escape is limited to the opening through the disk portion/floor of the insert. Once the fluid level rises to cover that opening, then there is no path for air to escape from the inside of the vent plug.

The claims appended hereto are meant to cover all modifications and changes within the scope and spirit of the present invention.