Lifting assembly and methods

Abstract

A lifting assembly 100 for a battery pack 30 has first and second tension members (104,106 fig.7) and a harness having one or more elements (112,116 fig.8) for engaging a lower part of the battery pac

Description

The present invention relates to a lifting assembly for a battery pack, related uses and methods of lifting a rechargeable battery pack. The lifting assembly and methods may be used in mounting / demounting a rechargeable battery pack to a transport refrigeration unit of a type configured to draw power from rechargeable batteries in cooling the interior of a mobile enclosure, such as in a trailer or lorry. Rechargeable battery packs are known in many industries. Most of the development work to date has been in the field of Electric Vehicles. However, there are other applications where rechargeable batteries are to be used where approaches used in the EV field are not suitable or non-optimal. To take one example, there have been recent attempts to provide transport refrigeration units that are powered by rechargeable batteries. Transport Refrigeration Units (TRUs) comprise a refrigeration system that, when driven, blows chill air into one or more compartments in the interior of a container to cool the contents and play an important role for the food distribution industry in delivering fresh, frozen, and other perishable food from field to market. These are used with small rigid vans / trucks right through to use with a tractor unit pulling a semi-trailer (known as a semi-trailer truck in the US, an articulated lorry in the UK and various other names in other countries), where the TRU is added to a specially designed and insulated trailer. Traditionally TRUs are diesel driven, particularly when used with trailers. Such units are well established in the industry, but have a number of drawbacks including noise and exhaust emissions. To address the inefficiencies associated with regular diesel-driven TRUs, some hybrid designs and eTRUs have been proposed using solar power and / or batteries to supplement and / or supplant other power sources in powering the refrigeration unit. More recently, the present applicants have proposed in PCT / EP2021 / 062825, filed 14 May 2021, entitled "Electric Mobile Refrigeration Unit", the entire contents of which are hereby incorporated by reference in their entirety, a refrigeration unit powered by rechargeable batteries, optionally supplemented by solar, to minimise or eliminate the need for diesel power from the tractor unit or separate generator to power the refrigeration system. Despite the advent of battery powered TRUs, relatively little thought has hitherto 19 05 25 gone into how to most effectively physically accommodate and maintain the batteries in such systems. For instance, the space available for batteries is often tightly constrained. Accessibility is an important concept in battery placement, e.g. for serviceability. It may be desirable to remove the batteries from the TRU for 5 maintenance or replacement. The weight of the batteries must also be properly supported and transferred to the trailer in use and during the process of removing the battery from the TRU. Consideration should also be given to ease and cost of manufacturing the unit, reliability, as well as maintenance and servicing the units in the field. 10 It should be noted that it is known in the prior art for diesel driven TRUs to include small batteries to power the electronics and start up of the refrigeration system. However, these batteries are small and not intended or capable of providing the main source of power to the refrigeration system, and so the fitting such a small battery into 15 the confines of the TRU or achieving high battery densities becomes less of a concern. The present disclosure is concerned with battery packs suitable for providing the TRU's primary source of power, possibly supplemented by solar or other sources, and it is desired to incorporate a large volume of battery power capable of driving the refrigeration system, i.e. as sometimes called "traction batteries", into the TRU itself in 2 0 an optimum way. The present invention aims to address some or all of these and other problems in the prior art both in the field of transport refrigeration units and in other applications where rechargeable batteries are used to power a mobile device. 25 According to a first aspect of the present invention, there is provided a lifting assembly for a battery pack, the lifting apparatus comprising: A first and second tension member, descending one on either side of the battery pack, by which the battery pack is lifted during a lifting operation, each tension member 3 0 comprising a flexible member; a harness comprising one or more elements for engaging a lower part of the battery pack, wherein the harness is connected with the first and second tension members at the respective sides of the battery pack ; and first and second arms configured to attach to an upper part of the battery pack, 35 wherein the first and second arms extend away from the respective sides of the battery pack and engage with the first and second tension members respectively to position and 19 05 25 space them apart from the sides of the battery pack to provide increased clearance above the battery pack during the lifting operation, wherein the flexible members of the tension members are able to slip relative to the arms (140) or turn about a pulley (144) at the end of the arms such that at least a majority of the weight of the battery pack is 5 supported by the harness during the lifting operation and transmitted to the tension members. Thus, the battery pack is lifted from underneath or a lower part of the battery (i.e. preferably at least 50% down the vertical extent of the battery pack and more preferably 10 at least 75%), whilst the arms at an upper part of the battery pack (i.e. preferably at least 50% down the vertical extent of the battery pack and more preferably at least 75%) act to stabilise the lifting element, i.e. to stop the battery pack from swinging or inverting when lifted, as well as to move it outboard of the battery pack so that, when lifting the battery pack into or out of position to be fitted to the machine being powered by the 15 battery, the upper tension elements extending down the sides have additional lateral clearance to avoid snagging the machine to which the battery is fitted above the battery. This may be particularly advantageous where the battery is used to power a transport refrigeration unit, which are typically constrained to having a shallow cuboid 2 0 volume with the battery pack mounted below the refrigeration system in the TRU. In general, the tension members, e.g. ropes, wires, cables, chains, rods etc, will descend on either side of the TRU in a substantially vertical direction at a set separation from the side of the TRU, e.g. 10 cm or 20 cm or more, with the distance of the separation dictated by the arms at the bottom and by their points of attachment to the lifting 2 5 mechanism at the top, e.g. winches, forklift etc. However, the lifting mechanism may be used with other types of battery, particularly where they are mounted in a generally vertical orientation to a vertical surface, e.g. for powering trams, light railways, and other vehicles, or mounted to buildings, e.g. powering HVAC systems, or to any other structure or freestanding. 30 The arms provide a mechanism for engaging with the tension members by which the majority of lifting force is translated to the harness such that the harness bears the all or a majority of the weight of the battery pack (preferably >75%) with optionally some of the weight being carried by arms in some embodiments, as discussed herein. This is 35 generally accomplished by including a joint such as a pivot in the arm and / or allowing the tension element to slip relative to the arm such to reduce or eliminate the bending 19 05 25 moment transmitted to the arms. This avoids the need for the arms to be cantilevered, which would be required if the arms were fixed to the battery pack and to the tension members such that the lifting force was directly transferred to the arms creating a large bending moment which, undesirably, would need to be resisted by the structural 5 framework of the battery by strengthening the framework. The tension elements are typically angled below the points they engage with the arms, due to attaching with the harness at points that are typically adjacent to the respective sides of the battery pack at the lower part of the battery pack and with the 10 ends of the arms, which are outboard the sides of the battery pack, at the higher part of the battery pack. Thus, the arms typically maintain an angle between the parts of the tension elements above the arms, which are typically vertical or close to vertical, and the parts of the tension elements below the arms, which may be between 5 degrees and 30 degrees to the vertical in preferred embodiments. The flexible member or linked 15 members allow this angle to develop in the tension member. A single cable or the like may be provided at each side of the battery pack, with an upper part, above the arm, being attached to the lifting apparatus, e.g. fork lift, , and a lower part, below the arm, providing transmitting the lifting force to the harness. 2 0 According to a second aspect of the present invention, there is provided a lifting assembly for a battery pack A lifting assembly for a battery pack, the lifting apparatus comprising: a first and second lifting tension member, descending one on either side of the battery pack, by which the battery pack is lifted during a lifting operation; first and second arms configured to attach to an upper part of the battery pack, wherein the first 2 5 and second arms extend away from the respective sides of the battery pack and link to the first and second lifting tension members respectively to position and space them apart from the sides of the battery pack to provide increased clearance above the battery pack during the lifting operation; and a harness comprising one or more elements for engaging a lower part of the battery pack, wherein the harness is 3 0 connected with first and second harness tension members at the respective sides of the battery pack which link to the end of the respective arms at each side, wherein the arms include a joint such that at least a majority of the weight of the battery pack is supported by the harness during the lifting operation and transmitted via the harness tension members and arms to the lifting tension members. In an embodiment the end of the arm comprises an eyelet through which the 19 05 25 respective tension member passes. In an embodiment the arms are removably attached to the battery pack. 5 In an embodiment, the arms are fixed to the battery pack, and can optionally pivot to a non-deployed position to reduce the overall width of the battery pack for when the battery pack is in use. In an embodiment, the assembly comprising a spreader beam to which ends of 10 the first and second tension members attach at laterally spaced apart points by which the battery pack can be lifted. These points may coincide with the width of the arms, i.e. so that the tension elements extend down from the spreader beam in a generally vertical fashion. 15 In an embodiment the spreader beam has fixtures configured to engage with the forks of a fork lift truck and or fixtures for being hoist by a crane. In an embodiment the tension members engage with the ends of the arms at 2 0 least 10 cm outside the footprint of the battery pack. In other embodiments, there may be at least 20 cm clearance, or 30 cm clearance or more. Generally it is not necessary or desirable to have more clearance than this. 25 In an embodiment one or more tension members is selected from one or more of: a rope; a wire; 3 0 a cable; a strap; a chain; a rod; and a strut. In an embodiment the harness is reversibly attachable to the battery pack. 19 05 25 In an embodiment a shackle is used to attach a least one tension member to the battery pack and / or to the arm. In an embodiment the arms are substantially horizontal when mounted to the 5 battery pack to within plus or minus 25 degrees. According to a third aspect of the invention, there is provided a lifting assembly according to any preceding claim in combination with a battery pack. 10 According to a fourth aspect of the invention, there is provided a lifting assembly according to any preceding claim in combination with a battery pack and a TRU, wherein the tension members engage with the ends of the arms at least 5 cm outside the footprint of the TRU. 15 For instance, the battery pack may have approximately the same width as the TRU, i.e. to maximise use of the available volume in the TRU. By moving the tension members outboard of the TRU via the arms, the descending tension members are less likely to interfere with elements of the TRU above the battery pack during the lifting operation. 20 According to a fifth aspect of the invention, there is provided use of the lifting assembly of any preceding claim in lifting a battery pack in the process of mounting or demounting the battery pack to a transport refrigeration unit. 2 5 According to a sixth aspect of the invention, there is provided a method of demounting a battery pack from a transport refrigeration unit mounted to a truck or trailer using the lifting assembly as described above, the method comprising: engaging the lifting assembly with the battery pack; lifting the battery pack via the tension members, wherein the tension members 3 0 are kept laterally outside the TRU envelope by the arms extending outwards; detaching the battery pack from the TRU and / or truck or trailer; moving the battery pack away from the TRU and optionally disengaging the lifting assembly from the battery pack. 35 According to a seventh aspect of the invention, there is provided a method of mounting a battery pack from a transport refrigeration unit mounted to a truck or trailer using the lifting harness as described above, the method comprising: engaging the lifting assembly with the battery pack; lifting the battery pack via the tension members to support the weight of the battery pack; offering up the battery pack to the TRU, wherein the tension members are kept laterally outside the TRU envelope by the arms extending outwards; attaching the battery pack to the TRU and / or truck or trailer; disengaging the lifting assembly from the battery pack. In an embodiment, engaging the lifting assembly with the battery pack comprises one or more of: engaging the harness with the battery pack; engaging the tension members with the arms; attaching the arms to the sides of the battery pack; and / or disengaging the lifting assembly with the battery pack comprises one or more of: disengaging the harness with the battery pack; disengaging the tension members with the arms; detaching the arms from the sides of the battery pack. It will be appreciated that any features expressed herein as being provided “in one example” or “in an embodiment” or as being “preferable” may be provided in combination with any one or more other such features together with any one or more of the aspects of the present invention. Embodiments of the present invention will now be described by way of example with reference to the accompanying drawings, in which: Figure 1 shows a perspective view of an example from the front of an example of a TRU including a battery pack; Figure 2 shows a front view of another example of a TRU when viewed from the front with the battery pack separated from the rest of the TRU; Figure 3 shows an example of a structural framework for a battery pack; Figure 4 shows a perspective view of an example of a lifting apparatus for lifting the battery pack with a forklift truck according to an embodiment of the invention; Figures 7 to 9 show detailed views of parts of the lifting apparatus; Figure 10 shows another example of a lifting apparatus according to an embodiment of the invention; and Figure 11 shows yet another example of a lifting apparatus according to an embodiment of the invention. Figure 1 shows a perspective view of an example of a transport refrigeration unit (TRU) 10, attached to the front of a semi-trailer 1 of the sort that can be attached to and pulled by a tractor unit (not shown) for transporting goods loaded to the interior of the trailer via doors at the rear of the trailer. Generally in the following description references to the “front” are in the direction of arrow 16, i.e. the forwards direction of the trailer; the “rear”, arrow 17; the “top”, arrow 18; the “bottom”, arrow 19 and the “to the sides” or “outboard”, numerals 15. It will be appreciated that the TRU may equally be attached to other vehicles types, such as rigid body trucks, vans and lorries, or containers such as shipping containers that can be lifted onto a trailer for transportation and may be generally applicable to cooling the interior of any enclosure. Although the unit has been described as cooling the interior of the trailer, it may also be arranged to heat the interior of the trailer. The TRU 10 is shown in Figure 1 without the external covers that would normally be installed to weatherproof the TRU in order to show the components more clearly (the TRU with covers is shown by Figure 4). The TRU 10 comprises a structural framework 20 which supports the various elements of the unit. This generally comprises side members 20a and cross members 20b spanning between the side members 20a, and which provides attachment points 20c for fixing it to the trailer, which are generally provided at the sides, e.g. in vertical side members 20a and top and bottom cross members 20b, so as to be accessible. The framework 20 generally defines a first volume 22,23 which houses a vapour compression refrigeration system 28 and a second volume 24 below the first volume which housing a rechargeable battery pack 30 for powering the refrigeration system, optionally in combination with solar power. The vapour compression refrigeration system 28 comprises primarily the evaporator, compressor 45, condenser 50, and expansion valve 51, together with fans 55 for moving air over the condenser and fans for moving air over the evaporator. When the compressor and fans are driven, these combine to blow chilled air into the interior of the trailer 12 through an aperture (not shown) in the end wall of the trailer 25 to cool the content, as is generally well known in the art. Within the first volume, the compressor and evaporator and their respective fans occupy an upper portion 22 with the evaporator and its fans located behind the condenser at the rear of the TRU (not shown in Figure 1). In the lower portion 23 of the first volume, the compressor 45 is mounted to a shelf 20d of the framework 20. Power distribution and / or system control electronics 35 and a motor and motor controller 36,37 for driving the compressor 45 are also located in this portion of the first volume, as well as potentially smaller elements of the refrigeration system, such as the expansion valve, other valves, heat exchangers, etc. and of course the necessary connecting pipework. The TRU 10 may also comprise communication means for transferring data with a remote service that can manage or monitor the TRU, a UI by which an operator can control the TRU, connectors for connecting to solar panels on the roof of the trailer or shore power when the trailer stationary. These may be mounted to any suitable point in the framework and communicate with the battery pack and the refrigeration system as required. The rechargeable battery pack 30 is demountable from the rest of the TRU 10 so that the battery pack can be removed for maintenance or replacement. In the example of Figure 1, a unitary structural framework 20 is used for the TRU to which the battery pack mounts. Thus, the framework defining the upper and lower compartments is unitary and the battery pack is fixed to a lower portion of the framework. In this example, side members 20a of the framework extend substantially the entire height of the TRU 10 and the battery pack reversibly mounts to a lower portion of these side members via appropriate fixings, e.g. bolts. In contrast, in the example Figures 2a and 2b, the TRU framework 20 may be provided in separable parts, respectively for the upper volume 22,23 and lower volume 24. Thus, the lower part of the framework, e.g. vertical side members 20ab, which support the battery pack in attaching to the trailer may be separate from the upper part of the framework 20aa which supports the refrigeration system in attaching to the trailer. Joining flanges 20e are provided by the battery pack for fixing to the upper part of the framework 20a at points 20f (or the upper framework for fixing to the lower framework, or both) to reversibly structurally connect the two parts via appropriate fixings, e.g. bolts. This enables the lower part of the framework to be incorporated into the structure of the battery pack 30 itself. Thus, in effect, a refrigeration system pack and a battery pack are provided which may be connected together to form the TRU, both of which incorporate structural elements with attachment points 20c for mounting to the truck or trailer via fixtures. This arrangement of incorporating structural members into the battery pack 30 by which it is directly attached to the trailer may increase the structural integrity of the battery pack so the battery pack is better able to remain fixed to the trailer face in the event of a crash. Nonetheless, other arrangements for reversibly mounting the battery pack to the rest of the TRU and / or the trailer may be implemented as appropriate. In any case, preferably the mounting of the battery pack is such the battery pack is accessible at the front of the TRU (when the covers are removed) and by releasing accessible fasteners fixing the battery pack to the rest of the TRU or trailer, and any electrical connections, the battery pack can be removed from the rest of the TRU and trailer. The battery pack 30 comprises a structural framework 33 defining within a battery compartment 40 including plural battery modules 41 (as shown in isolation in Figure 3). Front and rear covers 35,36 (shown in Figure 6) cooperate with the framework to seal the battery compartment 40 such that moisture cannot penetrate to the battery modules. The framework provides structural support to the battery pack including i) mounting the battery modules inside and other components, and ii) allows it to be attached to the TRU framework 20 via the fixtures 34 in the example of Figure 1 or to be attached to the upper framework 20a and to the trailer in the example of Figure 2. As described below, the framework is also adapted to aid the process of lifting the battery pack via a lifting apparatus when mounting / demounting the battery pack from the rest of the TRU. In this example, there are 3 rows 44a,b,c of 8 battery modules 41, each of which contain plural battery cells in a housing strong enough to be handled / mounted. In each row, the 8 battery modules 41 are connected in series to give, for example, two battery modules stacks of 4 modules each. The battery module terminals 42 are preferably at the top when the modules are fixed in place and the battery cells are preferably in an upright orientation when the stacks are fixed in the pack. The battery modules as preferably identical in size, voltage / capacity, and arrangement of cells within. Within the framework 33, each row 44 of battery modules is supported by a shelf 50a,b,c running laterally across the battery pack, i.e. in a left right direction. The shelves are connected at the sides to vertical left and right side members 52a,b. The side members are generally L-shape in cross section, one leg attaching to the shelves and one leg extending laterally away from of the battery compartment providing a flange for attaching to the main body of the TRU via fixtures in the example of Figure 1, or being attached to the vertical side members 20b in the example of Figure 2. A top member 54 runs across the top of the battery pack also connected at the sides to the left and right side members. The shelves, top member and top member form a structurally rigid battery support framework 20. Further members 53 may be provided between the shelves and / or elsewhere to brace the framework. A battery management unit (BMU) 75 is provided for each battery module stack 41 within the battery compartment 40 mounted to the front of the shelves 50. The front and rear covers 35,36 are attached, preferably removably by fixings, to the side members, shelves and top members at least around the periphery of the open front 57 and rear faces 58 (and optionally to any the intermediary shelves) to help brace and structurally strengthen the assembly and also create a seal such that the battery compartment within is kept dry in use, i.e. sealed from ingress of rain, spray and dirt from the road, condensation in the refrigeration compartment, e.g. to within IP67 standard, or any appropriate standard. Outside of the battery compartment, the battery pack also has fan units 62 forming part of the thermal management system 60 of the battery pack mounted at one side. Connectors 70 for making electrical contact between the battery pack and the electrical system of the TRU, i.e. to provide power from the battery pack to the refrigeration system, are also provided, here positioned at the opposite side to the fans. Chargers 72 may be conveniently mounted underneath the battery pack for charging the batteries (e.g. from AC grid when at the depot and / or from solar power attached to the trailer in transit or at the depot). The shelves are configured to aid in removing heat from the battery modules as well as from the battery management units and thus form part of the thermal management system 60. The shelves include channels 51 running laterally through them, i.e. in a left / right direction. The fan units 62 draw air 66 through these channels 51 to provide a cooling airflow drawing heat away from the shelves and thus from the battery modules and BMlls in contact with the shelves. The channels 51 in the shelves are sealed, i.e. do not allow air into the interior of the battery compartments so the waterproofing of the battery compartment is not compromised, whilst allowing heat to be transferred away from the battery compartment via the shelves. The battery framework may be made, for instance, from extruded aluminium with parts welded or fixed together as required. It contemplated that the fan units, contactors and chargers may be serviced in the field, e.g. by swapping out for new units. These can be accessed at the sides and underneath the unit by removing the side TRU covers without unsealing the battery compartment or even removing the battery pack form the TRU. However, the battery pack is intended to be a sealed unit which is not serviceable in the field for replacing, say, battery modules that have failed. Preferably the entire battery pack is removed and swapped out in this scenario. However, the battery pack is typically heavy meaning that the problem arises of how best to support and lift the battery pack as it is detached and lifted away from the TRU. Figures 4 to 9 show an example of a lifting apparatus 100 for the battery pack 30. Figure 4 shows the lifting apparatus 100 engaged with the battery pack 30 and a forklift 150 positioned and ready to lift the battery pack 30 free of the rest of the TRU 10 and trailer 1. Figures 5 and 6 show from the front and rear the forklift 150 having lifted the battery pack 30 clear of the rest of the TRU 10 and trailer 1. The lifting assembly 100 comprises a spreader beam 102 and for each side of the battery pack a pivotable arm 110 attached to an upper part of the side of the battery pack. A tension member (e.g. an upper and lower rope in this example) 104,106 connects the spreader bar 102 to a harness via in this example linkages to the end of the pivoting arm 110. In particular, the upper rope 104 attaches between the spreader bar 102 and the arm 110 and the lower rope 106 attaches between the arm and the harness. The harness engages with and supports a lower part of the battery pack.. When the spreader bar is lifted, the majority of the lifting forces in the tension members above the arms, i.e. upper ropes, are transmitted via the lower ropes to the harness and thus to the bottom portion of the battery pack. The spreader beam 102 includes channels 102a arranged to receive the arms of a forklift to allow the lifting assembly 100 to be lifted via the forklift. The upper ropes 104 attach to the ends of the spreader beam, preferably reversibly e.g. via shackles 102b. The spreader beam 102 may be made from box steel or similar structural material. Figure 7 shows the arrangement of ropes 104,106 and pivotable arm 110 at a side of the battery pack in more detail, with Figure 8 showing the attachments to the pivotable arm 110 in more detail and Figure 9 showing the attachment to the lower part 108 of the battery pack in more detail. NB, while ropes are used in this example, any tensile member, though preferably flexible or comprising linked member and / or preferably thin, may be used, e.g. including chains, straps, wires, cables, rods, struts, etc. which carries tension when under load. As shown by the detailed view of Figure 8, the arm 110 is pivotably attached at one end to the battery pack framework at the top of the battery pack and extends outwards to the side of the battery pack. The top rope and bottom rope attach to the other end of the arm, preferably reversibly, e.g. via shackles 112,116, through holes 114,118 in the arm. As shown by the detailed view of Figure 9, the bottom rope extends downwards and inwardly from the arm to reversibly attach, e.g. via a shackle 119, to a plate 108 incorporated with the structural framework of the battery, e.g. side members 20ab in Figure 2, at the bottom of the battery pack at that side. The shackles at the end of the lower ropes may be thought of as forming a cradle or harness 106 for supporting the majority of the weight of the battery pack during a lifting operation, thereby eliminating any cantilever effect on the arm and allowing it to be significantly less strong then it would otherwise need to be. Other forms of harness are possible for supporting the lower part of the battery. In any event, the harness is connected to the lifting members such that the lifting force is transmitted to the harness as mediated by the mechanism provided by the arms and their engagement with the lifting members. As shown by Figure 8, the arm 110 is attached via pivot 120 to a beam 122 which is reversibly attached, e.g. via fasteners 124, to the structural framework of the battery pack at the side, e.g. to side members 20ab Figure 2. This allows the arm 110 and beam to be removed from the battery pack 30 when the battery pack is not being lifted, i.e. when the battery is in use. To remove the battery pack from the TRU, forklift arms are engaged with the receiving features in the spreader beam 100 and positioned so as to be above the TRU. The lifting assembly 100 is then attached to the battery pack, i.e. the arms 110 are attached to the battery pack and the lower ropes are attached to plates 109. The forklift arms are then be raised until the ropes take the weight of the battery pack. The battery pack fasteners can then be released, so the battery pack comes free of the rest of the TRU and / or the trailer. The forklift can then reverse away from the trailer carrying the battery pack clear of the TRU. The battery pack is then typically laid flat on a surface, e.g. the bed of a truck for being transported elsewhere, or attached to a supporting jig or trolley for maintenance on site, etc. . The procedure is reversed to mount a battery pack to the trailer / TRU. The spreader bar 100 and arms 110 are sized such that the upper ropes are clear of the sides of the TRU to avoid these coming into contact during the procedure, i.e. the width of the spreader bar and points of attachment of the rope to the ends of spreader bar are outboard of the sides of the TRU by preferably at least 5 cm, or more preferably at least 10 cm, or even more preferably at least 20 cm and similarly the arms are sufficiently long that the points of attachment of the upper ropes to the arms are outboard of the sides of the TRU by preferably at least 5 cm, or more preferably at least 10 cm, or more preferably at least 20 cm. The upper ropes are preferably substantially vertical, but may have slight angles as long as clearance to the TRU is maintained. Thus, with a typical TRU of width2meters the upper ropes may be at least 2.1 meters apart to give clearance for the TRU when lifting the battery pack. The pivoting nature of the arms means that the tension in the upper rope supporting the weight of the battery pack is largely transferred to the lower rope and thereby transferred to plate 108. Thus, the battery pack is lifted essentially from the bottom meaning that the battery pack structure is largely in compression under its own weight as it is lifted, with the arms engaging with the tension members to stabilise the battery pack as it is lifted and prevent it flipping upside down. The arms experience a relatively minor component of this force due to the angled lower ropes, but this force is largely compressive, i.e. acting inwards along the arms, which the battery pack structure can more easily tolerate. The pivoting nature of the arms means that no bending moment is transferred to the battery pack structure. This arrangement is advantageous compared with a possible example where the arms are fixed and the ropes simply attach to the arms. In this example, the arms would need significantly more bracing, e.g. to be cantilevered in some way, to bear the weight of the battery pack. The battery pack structural framework would also experience different forces in this example, i.e. the side members would be in tension, rather than compression, as the battery pack is lifted from the top rather than from the bottom, which may require a more bulky and heavy structural framework for the battery. Other embodiments are possible. For instance, in the lifting assembly 110A of Figure 10, instead of pivoting at their near ends close to where they connect to the battery framework as in the previous example 100, the arms 110A could be fixed to the battery framework, e.g. side members 20ab, and have eyelets 140 in their far ends through which the tension members pass. Thus, instead of the tension members comprising upper and lower ropes both attaching to the arm, they are provided as a single, continuous rope at each side, depending from the spreader bar, running through the eyelets and attaching to the plates 109 at the bottom of the battery pack. The arms perform a similar role in engaging with the rope and maintaining the angle of the upper part of the rope relative to the lower part of the rope so as to be outboard of the battery pack and avoid interfering with the TRU as the battery pack is lifted. The ability of the rope to move through the eyelet, i.e. it is not fixed to the arm, means little or no bending moment is transferred to the battery pack structural framework through the arm whilst carrying the weight of the battery pack. As illustrated, the force F transmitted to the arm from the tension in the ropes acts mainly along a line bisecting the angle of the ropes (assuming little or no friction between the rope and eyelet). Due to the shallow angle theta between the bottom rope and vertical top rope, the main component of this force (Fa) acts laterally compressing the laterally extending arm, with thus only a relatively small component (Fb) giving rise to a bending moment on the arm with the depicted horizontal arm orientation. Of course, the angle of the ropes, their attachment points and the angle of the arm may be altered to further reduce this bending moment to substantially nothing if required, i.e. so the force transmitted by the ropes on the arm acts along its length and generates no bending moment on the arm or its attachment to the battery framework. In general, it is preferred that the arm is horizontal within plus or minus 25 degrees. In a further embodiment, as shown by Figure 11, the lifting assembly 100B is similar to that of Figure 10 except the arms are provided with pulleys at the ends instead of eyelets in Figure 10 about which the ropes can pass to reduce friction. Like the example of Figure 10, this gives rise to only relatively small bending moments in the arm. Thus, various arrangements of arms are provided by which the harness supporting the lower part of the battery pack is connected to the lifting tension members such that the lifting force is transmitted to the harness as mediated by the mechanism provided by the arms such that all or the majority of the weight of the battery pack (preferably >75%) is carried by the harness and none or a minority of the weight of the battery pack (preferably <25%) is carried by the arms. The lifting assembly 100 is preferably removable from the battery pack during use. This avoids carrying excess weight and allow a single lifting assembly to be used to service multiple batteries, e.g. when managing a fleet of vehicles at a depot. Nonetheless, some or all parts of the lifting assembly could be permanently attached to the battery pack if desired. For instance, the arms could be a unitary part of the battery pack structural framework and, in the example of Figure 7, simply pivot down to be flush with the side of the battery pack and so out of the way when the TRU is in operation. The above examples use shackles for attaching the tension members to the spreader beam, arms, and plates of the battery pack. Other ways of attaching the tension members may be used. The lower ropes attaching to the battery plates may for instance attach to a support platform or sling extending underneath the battery pack to support the battery pack, rather than to the battery pack itself. Other forms of harness for engaging with and supporting the lower part of the battery pack are contemplated. Tension members may comprise one or more linked elements as may be convenient. While a fork lift truck has been shown lifting the lifting assembly in the illustrated examples, it will be appreciated that other lifting devices may be used, e.g. a hoist, gantry, crane etc. The spreader beam may be incorporated into the lifting device itself where appropriate, e.g. the ropes may be attached to the lifting device itself where the lifting device offers suitably located attachment points, e.g. to a gantry, that has the necessary width to attach the ropes outboard of the TRU footprint. 5 Embodiments of the present invention have been described with particular reference to the examples illustrated. However, it will be appreciated that variations and modifications may be made to the examples described within the scope of the present claims. 10

Claims

1. A lifting assembly (100) for a battery pack, the lifting apparatus comprising:a first and second tension member (142), descending one on either side of the battery pack (30), by which the battery pack is lifted during a lifting operation, each tension member comprising a flexible member;a harness comprising one or more elements (119) for engaging a lower part (30b) of the battery pack, wherein the harness is connected with the first and second tension members at the respective sides of the battery pack; andfirst and second arms (110a, 11 Ob) configured to attach to an upper part (30a) of the battery pack, wherein the first and second arms extend away from the respective sides of the battery pack and engage with the first and second tension members respectively to position and space them apart from the sides of the battery pack to provide increased clearance above the battery pack during the lifting operation,wherein the flexible members of the tension members are able to slip relative to the arms (140) or turn about a pulley (144) at the end of the arms such that at least a majority of the weight of the battery pack is supported by the harness during the lifting operation and transmitted to the tension members.

2. A lifting assembly (100) for a battery pack, the lifting apparatus comprising:a first and second lifting tension member (104), descending one on either side of the battery pack (30), by which the battery pack is lifted during a lifting operation;first and second arms (110) configured to attach to an upper part (30a) of the battery pack, wherein the first and second arms extend away from the respective sides of the battery pack and link to the first and second lifting tension members (104) respectively to position and space them apart from the sides of the battery pack to provide increased clearance above the battery pack during the lifting operation; anda harness comprising one or more elements (108) for engaging a lower part (30a) of the battery pack, wherein the harness is connected with first and second harness tension members (106) at the respective sides of the battery pack which link to the end of the respective arms at each side,wherein the arms include a joint (120) such that at least a majority of the weight of the battery pack is supported by the harness during the lifting operation and transmitted via the harness tension members and arms to the lifting tension members.

3. A lifting assembly according to claim 1, wherein the end of the arm comprises an eyelet through which the respective tension member passes.

4. A lifting assembly according to any preceding claim, wherein the arms are removably attached to the battery pack.

5. A lifting assembly according to any of claims 1 to 3, wherein the arms are fixed to the battery pack, and can optionally pivot to a non-deployed position to reduce the overall width of the battery pack for when the battery pack is in use.

6. A lifting assembly according to any preceding claim, comprising a spreader beam to which ends of the first and second tension members attach at laterally spaced apart points by which the battery pack can be lifted.

7. A lifting assembly according to claim 5, wherein the spreader beam has fixtures configured to engage with the forks of a fork lift truck and or fixtures for being hoist by a crane.

8. A lifting assembly according to any preceding claim, wherein the tension members engage with the ends of the arms at least 10 cm outside the footprint of the battery pack.

9. A lifting assembly according to any preceding claim, wherein one or more tension members is selected from one or more of:a rope;a wirea cable;a strap;a chain;a rod; anda strut.

10. A lifting assembly according to any preceding claim, wherein the harness is reversibly attachable to the battery pack.

11. A lifting assembly according to any preceding claim, wherein a shackle is used to attach a least one tension member to the battery pack and / or to the arm.

12. A lifting assembly according to any preceding claim, wherein the arms are substantially horizontal when mounted to the battery pack to within plus or minus 25 degrees.

13. A lifting assembly according to any preceding claim in combination with a battery pack.

14. A lifting assembly according to any preceding claim in combination with a battery pack and a TRU, wherein the tension members engage with the ends of the arms at least 10 cm outside the footprint of the TRU.

15. Use of the lifting assembly of any preceding claim in lifting a battery pack in the process of mounting or demounting the battery pack to a transport refrigeration unit.

16. A method of demounting a battery pack from a transport refrigeration unit mounted to a truck or trailer using the lifting assembly of any of claims 1 to 13, the method comprising:engaging the lifting assembly with the battery pack;lifting the battery pack via the tension members, wherein the tension members are kept laterally outside the TRU envelope by the arms extending outwards;detaching the battery pack from the TRU and / or truck or trailer;moving the battery pack away from the TRU andoptionally disengaging the lifting assembly from the battery pack.

17. A method of mounting a battery pack from a transport refrigeration unit mounted to a truck or trailer using the lifting harness of any of claims 1 to 13, the method comprising:engaging the lifting assembly with the battery pack;lifting the battery pack via the tension members to support the weight of the battery pack;offering up the battery pack to the TRU, wherein the tension members are kept laterally outside the TRU envelope by the arms extending outwards;attaching the battery pack to the TRU and / or truck or trailer;disengaging the lifting assembly from the battery pack.

18. A method according to claim 15 or 16,wherein engaging the lifting assembly with the battery pack comprises one or more of:engaging the harness with the battery pack;engaging the tension members with the arms;attaching the arms to the sides of the battery pack;and / orwherein disengaging the lifting assembly with the battery pack comprises one or more of:disengaging the harness with the battery pack;disengaging the tension members with the arms;detaching the arms from the sides of the battery pack.

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