Portable power

Abstract

A portable power unit 100 comprises a substantially cuboid body with a mass of no more than 10 kg which comprises a front face comprising an output socket 113, and a charging connector 112 arranged to provide power from a standard electric vehicle charging plug to the portable power unit, the body being arranged to removably receive at least one battery module and comprising circuitry such that a received battery module can be charged via the charging connector and discharged via the output socket. The portable power unit further comprises a pair of grab- bars extending around one side perimeter of the body such that each grab bar contacts the upper and lower faces of the body along the full length of the body and at a respective side of the body, and extends beyond the front face such that there is a space of at least 1.2 cm between the front face and the portion of each grab-bar extending thereacross.

Description

The present invention relates to a portable charging unit which removably receives at least one battery module, and which can be charged via a charging socket of a type standard for electric vehicles. A fixed charging hub for charging a battery module for such a portable charging unit is also disclosed. Regulations and climate goals in the UK indicate that by 2030 all fleet vehicles and the tools they use must be fully electric. With a shift to electric tools, having a unit capable of powering them “in the field” is a necessity, as a mains electricity supply is not always available - for example on construction sites. A battery that can be taken from a van and moved to a jobsite is generally the most convenient option. A portable power unit aimed for commercial use has additional considerations as compared to domestic batteries. For example, scalability across a full fleet is an important consideration with fleet operators preferring a “one size fits all” approach, reducing maintenance complexity. Currently-available solutions generally comprise a battery unit with a capacity of 0.5-2 kWh capable of delivering continuous power of 0.5-2 kW in line with its capacity. The device’s charger is generally contained within the unit and is connected to the mains for recharging via a C13 IEC connector (kettle lead). Power is delivered from the unit to tools or other devices to be charged through one or two domestic-type sockets (to match standard plugs); these sockets are usually not capable of delivering their full rated current due to limitations of the unit. These prior art battery units are configured for consumer “lifestyle” applications where the unit is used for charging personal devices and powering small lights. Commercial applications have much higher power demands; e.g. large tools such as road-breakers may be used for prolonged periods throughout the day. This increases the required energy output and hence the required capacity. Connectivity to many tools is also limited with these units, with many tools requiring Commando-style sockets or domestic sockets capable of delivering their full rated power. Current solutions are also not optimised for working in fleets, with difficulties surrounding charging, flexibility, and effective utilisation of space. Unlike consumer applications, plugging in the unit when you return home brings challenges where energy metering and usage is concerned (e.g. an employee may be obliged to use his or her home electricity to recharge battery units and may not be able to easily distinguish this from household use so as to claim back costs) meaning units often must be returned to a depot to be recharged. The variability in use-cases across commercial usage means that no one unit can be the correct capacity for all tasks, so companies must allow for a selection of portable power units across the fleet. According to a first aspect, there is provided a portable power unit comprising: a body, the body being at least substantially cuboid in shape and comprising a front face comprising an output socket, a rear face opposing the front face, and upper, lower, leftside, and right-side faces extending between the front and rear faces, and a charging connector arranged to provide power from a standard electric vehicle charging plug to the portable power unit, the body being arranged to removably receive at least one battery module and comprising circuitry such that a received battery module can be charged via the charging connector and discharged via the output socket; and a pair of grab-bars, the grab-bars each extending around one side perimeter of the body such that each grab bar contacts the upper and lower faces of the body along the full length of the body and at a respective side of the body, and extends beyond the front face such that there is a space of at least 1.2 cm between the front face and the portion of each grab-bar extending thereacross. The body may have a mass of no more than 10 kg. In other embodiments, the mass may be more than 10 kg but no more than 20 kg or 25 kg. In some embodiments, the body may comprise one or more integral batteries - such embodiments may generally be heavier than embodiments without integral batteries (i.e. embodiments with power stored only in the removable battery module(s) received in the unit). The body of the portable power unit may be referred to as a carry case, as it is used to carry one or more battery modules, and the grab-bars may provide handles for ease of carrying by a user. As used herein, an “output socket” or “output connector” is a socket or (other) connector from which a power output is intended to be drawn from the portable power unit. The (or each) output socket may also be able to accept power input to the portable power unit. Equivalently, a “charging connector” or “charging socket” is a socket or (other) connector via which the portable power unit is intended to be charged - i.e. it is intended to receive a power input. The (or each) charging connector may also be able to provide power from the portable power unit -i.e. it may also be able to act as an output socket. Sockets / connectors may therefore be oneway or two-way, depending on the configuration of electronics of the unit, and may be labelled accordingly. Fleet vehicles generally have an associated allocated location where gear can be stored. Despite this fact, prior art solutions carry all componentry packaged in a single, non-modular, unit, making them heavier and bulkier especially for lower-power off-grid uses. The use of removable batteries, which may be stored and transported separately from a body of the portable power unit, therefore improves flexibility and ease of use. Swappable battery modules allow an increased system capacity without increasing overall weight of the portable unit - for example, even in embodiments in which the body can receive only a single battery module at once, a second battery module may be delivered when the first is running out, and swapped in when appropriate. The space between the grab-bars and the front surface may be sized to provide a handle, allowing a user’s hand to be inserted between the grab-bar and the body of the unit. The grabbar may be textured and / or comprise rubber (or any suitable polymeric) grips in some embodiments, to improve grip. Two front handles may therefore be provided, one by each grab-bar. This spacing of the grab-bars may also shield and protect the output socket, and optionally any plug mounted therein, from impacts by extending beyond that socket / plug. In embodiments in which the charging connector is located on a front face of the body, the charging connector may be similarly protected. This spacing of the grab-bars may also shield and protect an opening (and / or an openable hatch or similar covering that opening) into which the battery module is to be inserted. Improved flexibility may therefore be enabled whilst still providing a suitably ruggedised product. The charging connector may comprise a standard electric vehicle (EV) charging socket, such as a Type 2 charging socket. Associated power electronics may also be provided to adjust input power to meet battery module needs. Alternatively, or additionally in embodiments with multiple charging connectors, the charging connector may be arranged to be connected to a separate charging unit, the separate charging unit comprising a standard electric vehicle charging socket. The charging connector may comprise a socket, or an optionally-retractable cable. Use of a Type 2 charging socket or other standard EV charging socket - be that as an integral part of the portable power unit or as part of a charging unit connected to the portable power unit via a connector - may allow the portable power unit, and more specifically the one or more batteries therewithin, to be charged from a standard vehicle charger, so potentially allowing energy to be metered separately from household use. The output socket may be arranged to provide 230 V AC output, a 220 V or 240 V AC output, or any standard mains output power for a given country. The output socket may be arranged to provide at last 3 kW output power, and optionally 4 kW output power. Such an output may allow the unit to power almost any electric power tool, or indeed multiple tools concurrently. The output socket may be a standard mains socket, e.g. a socket for a three-pin domestic plug. The output socket may be a Commando socket. In some embodiments, multiple output sockets may be provided. The body may therefore comprise a plurality of output sockets. The body may comprise two 110 V Commando sockets, for example, or one 110 V Commando socket and one 230 V mains socket. In some embodiments with multiple sockets, two or more of the multiple sockets may be usable at their rated power / current simultaneously. In other such embodiments, a selection of a single socket to use at a given time may be needed (e.g. depending on maximum power / voltage output), at least if the full rated current is wanted. The space between the front face and the portion of each grab-bar extending thereacross may be at least at least 2 cm wide, and optionally at least 3-4 cm wide. The grab-bars may also each extend beyond the rear face such that there is a space of at least 1.2 cm, and optionally at least 2 cm, between the rear face and the portion of each grab-bar extending thereacross. This space may be sized to provide an additional handle towards the rear of the unit, allowing a user’s hand to be inserted between the grab-bar and the body of the unit. The grab-bar may be textured and / or comprise rubber (or polymeric) grips in some embodiments, at least in the “handle” region, to improve grip. A total of four handles may therefore be provided by the grab bars - one from each grab-bar at the front, and one from each grab-bar at the back of the unit. This spacing of the grab-bars may also serve to protect a rear surface of the power unit from impacts. In embodiments in which the charging connector is located on a rear face of the body, the charging connector may be similarly protected. The portable power unit may further comprise a battery hatch arranged to be openable so as to allow at least one battery module to be inserted and removed. The hatch may protect the battery module when in use, and may protect the interior space of the body when no battery module is present. In such embodiments, the battery hatch may be located in the front face. The battery hatch may therefore also be protected by the spacing of the grab-bars from the front face. In alternative such embodiments, the battery hatch may be located in the rear face - spacing of the grab-bars from the rear face, if present, may then protect the hatch. The portable power unit of may comprise a cover for each socket. The cover may protect the socket from foreign body ingress when not in use. The cover may be at least water-resistant, and optionally waterproof. The portable power unit may further comprise a power indicator arranged to visibly display an indication of remaining power available, for example in the form of one or more light-emitting diodes (LEDs). The body may be arranged to receive only a single battery module in some embodiments. In other embodiments, the body may be arranged to receive a plurality of battery modules, and optionally may comprise a separate hatch for each battery module to be received. Being able to add and remove battery modules form the body may have added advantages in units able to receive multiple battery modules at once - in particular, one or more battery modules can be carried separately from the power unit, so allowing a load to be split for carrying. Such a modular battery system also allows the device capacity to be scaled to the intended use - a user can pick up just as many battery modules as are needed, or remove unnecessary battery modules, rather than having to carry an unnecessarily heavy power unit. The body may comprise an inverter, arranged to convert direct current (DC) power from a received battery module to alternating current (AC) power for the output socket. Additional or alternative power electronics (e.g. one or more converters, transformers, and / or similar) may be provided for conversion of power - for example to adjust power input to charge the battery and / or to adjust power output to be appropriate for a given output socket. The body may comprise a monitoring system - the monitoring system may be arranged to monitor power unit performance and / or battery safety, and may comprise one or more of: • Battery state of charge monitoring; • Temperature sensing; • Current sensing; • Humidity sensing; • Pressure sensing; • One or more battery isolation sensors; • One or more accelerometers; and / or • Volatile Organic Compound (VOC) sensing, and / or one or more other gas sensors (e.g. hydrogen sensors) for battery safety monitoring. The body may comprise a monitoring system comprising one or more gas sensors including a Volatile Organic Compound sensor, and the portable power unit may be arranged to cut power flow to or from one or more received battery modules in response to gas detection by the monitoring system. The body may comprise a controller arranged to control energy flows between the output socket, charging connector, and one or more received battery modules. The grab-bars may extend further outward than the body along the sides of the body. Alternatively, the grab-bars may align with the sides of the body such that an outer edge of each grab-bar is coplanar with its respective side of the body. Preferably, the grab-bars are at least level with a surface of the body, if not spaced outwardly from it, to provide some protection from impacts. The total mass of the body and the grab-bars may be no more than 10 kg. It will be appreciated that the portable power unit may be sold and / or transported without batteries. However, the portable power unit may further comprise the at least one battery module. The or each battery module may have a mass of no more than 12 kg, and optionally of no more than 9 kg. According to a second aspect of the invention, there is provided a kit of parts comprising: a portable power unit as defined in the first aspect; and a plurality of battery modules each arranged to be removably received within the portable power unit. The portable power unit may be arranged to receive a maximum of one battery module at once, or may be arranged to receive a plurality of battery modules simultaneously. The or each battery module may have a mass of no more than 12 kg, and optionally of no more than 9 kg. The or each battery module may have a capacity of 0.5 kWh to 5 kWh, 1 to 5 kWh, or 1 to 3 kWh. The or each battery module may have a power output of 0.5-2.5 kWh, and optionally of around 2 kWh. A body of the portable power unit may be referred to as a carry case, as it is used to carry one or more battery modules, and generally provides at least one handle for ease of carrying by a user. The kit of parts may further comprise a battery module charging hub comprising a dock arranged to removably receive at least one battery module of the plurality of battery modules when that battery module is not within the portable power unit, and to provide power thereto. Battery modules may therefore be charged individually, instead of being charged within the power unit, when desired. This may allow a battery module to be carried elsewhere for charging whilst the power unit is still in use. The kit of parts may further comprise a portable power unit charging hub. The portable power unit may be connected to the hub and charged via the hub. Battery modules may therefore be charged via the power unit and hub, The charging connector of the portable power unit may comprise a cable. The cable may be retractable. In such embodiments, the kit of parts may further comprise a portable power unit charging hub comprising a standard electric vehicle charging socket. The charging connector cable may be arranged to be connected to the hub so as to transfer power from the hub to charge the portable power unit. The charging connector of the portable power unit may comprise a socket arranged to be connected to a cable. In such embodiments, the kit of parts may further comprise a portable power unit charging hub comprising a standard electric vehicle charging socket and a cable arranged to be connected to the charging connector of the portable power unit. The cable may be integral with the hub or may be separably connected thereto. The charging connector may be arranged to be connected to the hub via the cable so as to transfer power from the hub to charge the portable power unit. In any embodiments using a charging unit to charge the portable power unit, power electronics to adjust the input power as appropriate to suit one or more battery modules mounted within the portable power unit may be located within the hub instead of within the portable power unit, so reducing mass (and potentially also volume) of the portable power unit. Fleet vehicles generally have an associated allocated location where gear can be stored. Despite this fact, prior art solutions carry all componentry including power electronics packaged in a single unit, making them heavier and more bulky. The use of a hub which may be stored and transported separately from the portable power unit, and which may remain in a central location whilst the power unit is moved to where it is needed, therefore improves ease of use by making the power unit lighter. The kit of parts may therefore comprise a portable power unit charging hub, the hub comprising a standard electric vehicle charging socket, and wherein the hub is arranged to be connected to the charging connector so as to supply power to the portable power unit. The hub may comprise power electronics arranged to adjust input power to suit the power unit to be charged - for example converting an AC input to DC power. The charging unit may be referred to as a “hub” as there may be a single charging unit in a central location to which all portable power units are brought for charging. A cable may be used to transfer power from the hub to the power unit - the cable may be arranged to carry DC power. In other embodiments, the charging connector of the portable power unit may instead be a standard electric vehicle charging socket, and no intermediate cable and hub may be required. The skilled person would understand that features described with respect to one aspect of the invention may be applied, mutatis mutandis, to the other aspect of the invention. There now follows, by way of example only, a detailed description of embodiments of the present invention with reference to the accompanying drawings in which: Figure 1 is a perspective view of a portable power unit; Figure 2 is a second perspective view of the portable power unit of Figure 1, with a battery module being inserted thereinto; Figure 3 is a perspective view of the battery module of Figure 2 mounted on a charging hub; Figure 4 is a perspective view of a portable power unit with a different connector for charging, and an associated charging hub; Figure 5 is a perspective view of a portable power unit similar to that shown in Figure 4; Figure 6 is a different perspective view of the portable power unit of Figure 5; and Figure 7 is a perspective view of a portable power unit of Figures 5 and 6 with an associated charging hub. In the Figures, like reference numerals are used for like or corresponding features. Figure 1 shows a portable power unit 100 comprising a body 110 and a pair of grab-bars 150. The portable power unit 100 is arranged to removably receive a battery module 200, as described below. The portable power unit 100 shown is sized and shaped to receive a single battery module 200. In other embodiments, the portable power unit 100 is sized and shaped to receive a plurality of battery modules 200, for example two, three, four, or five modules 200. The power unit 100 may have a length of around 70 cm, and optionally between 50 cm and 80 cm. In the implementation shown in Figure 1, the length, including the extent of the grabbars 150, is around 68.5 cm. The power unit 100 pictured is substantially square in cross-section, having an at least substantially equal width and height (with differences in width and height due only to the grabbars in the embodiment shown), each in the range from 15 cm to 50 cm, and in the implementation shown around 29-31 cm. The power unit 100 may have different widths and heights in other implementations. The power unit 100 may have a maximum dimension (length, width, or height) of no more than 100 cm, and preferably not more than 75 cm, to facilitate carrying it. In various embodiments, the body 110 may have a length in the range from 50 cm to 60 cm, and a height and width each in the range from 25 cm to 35 cm, the height and width optionally being equal. In the implementation shown, the body 110 has dimensions of 56 cm (1) x 29 cm (w) x 29 cm (h). The portable power unit 100 and battery module 200 together may weigh no more than 30 kg, and optionally no more than 25 kg, 20 kg, or 15 kg in various implementations, so as to facilitate it being carried by hand. The portable power unit 100 and battery module 200 together may weigh at least 5 kg, and optionally at least 10 kg. In the embodiment shown in Figures 1 and 2, the portable power unit 100 has a weight of 20 kg with the battery module 200, and a weight of 10 kg without the battery module 200. More generally, the or each battery module 200 may have a mass of less than 12 kg, and optionally of less than 10 kg or 9 kg. The or each battery module 200 may have a mass of at least 2 kg, and optionally at least 5 kg. The portable power unit 100 is arranged to be carried by use of the grab-bars 150, the grabbars 150 being connected to the body 110. In the embodiment pictured in Figures 1 and 2, the grab-bars 150 are mounted to the body 110 - any suitable means known in the art may be used, for example welding or one or more connectors such as screws or bolts. In other embodiments, the grab-bars 150 may be formed integrally with the body 110. The grab-bars 150 may provide handles. The portable power unit 100 is arranged to house a battery module 200 and associated electronics, and to facilitate carrying the battery module 200 and associated electronics by hand. The portable power unit 100 may therefore be thought of as a carry-case for the one or more battery modules 200 it receives. The body 110 of the portable power unit 100 is at least substantially cuboid in shape, having a front face 1, a rear face 2 opposite the front face 1, and four further faces 3-6 extending between the front and rear faces. The corners of the body 110 are curved in the implementation shown, but may be sharp in other implementations. The four faces extending between the front 1 and rear 2 faces comprise a right side face 3, a left side face 4, an upper face 5 and a lower face 6. It will be appreciated that the faces 1-6 are described in relation to the orientation shown in Figure 1 for ease of reference, and that the portable power unit 100 may be positioned differently such that the “upper” face 5 is no longer facing upwards, for example - these labels are provided primarily for ease of description and should not be interpreted as limiting. The body 110 may therefore be described as having a right side perimeter extending around the edges of the right side face 3, and a left side perimeter extending around the edges of the left side face 4. The grab-bars 150 each extend around one side perimeter of the body 110 - the right-hand grab-bar 150a extending around the right side perimeter and the left-hand grab-bar 150b extending around the left side perimeter. The grab-bars 150 extend at least substantially parallel to the nearest face of the body 110. Each grab-bar 150 contacts the body 110 along at least substantially the full length of the body’s upper surface 5 and lower surface 6. In the embodiment shown in Figures 1 and 2, the grab-bars 150 are aligned with the respective side face 3, 4 of the body such that an outer surface of the grab-bar 150a, 150b is at least substantially coplanar with the respective side face 3,4. The full width of the grab-bar 150 therefore contacts the upper face 5 and the lower face 6. In other embodiments, the grab-bars 150 may each overhang the respective side face 3, 4 by a distance equal to a portion of the width of the grab-bar 150 - the overhang may provide some protection for the side faces 3, 4, for example if the portable power unit 100 were dropped on gravel. In various embodiments including those pictured, the grab-bars 150 may have a square crosssection, so providing a flat surface to contact the body 110, and to contact a surface on which the portable power unit 100 rests. The grab-bars may be differentlyO-shaped, e.g. having circular cross-sections, in other embodiments. The grab-bars 150 may have a width of between 10 mm and 80 mm, optionally of between 10 mm and 30 mm, and further optionally of between 15 mm and 25 mm. Each grab-bar 150 extends beyond the front face 1 of the body 110, such that there is a distance, d, between a rear side of the grab-bar 150 and the front face 1. The distance, d, is at least 2 cm in various embodiments, and may be at least 3 cm or at least 4 cm. In the example shown, the gap is around 5.4 cm between the grab-bar 150 and the front face 1. The distance, d, may be selected to be comfortably wide enough for a hand to fit between the grab-bar 150 and the body 110, so facilitating grip, lifting, and carrying of the portable power unit 100 - the spacing may effectively provide a handle. The distance, d, may be a minimum of 1.2 cm in various embodiments to provide enough space for an adult’s fingers to fit between the front face and the grab-bar. The distance, d, may also provide some protection for the front face 1, and more particularly for components of the front face 1 such as sockets as described below. In the embodiment shown in Figures 1 and 2, each grab-bar 150 also extends beyond the rear face 2 of the body 110, such that there is a distance, d, between a rear side of the grab-bar 150 and the rear face 2. In the example shown, the gap is around 2.5 cm between the grab-bar 150 and the rear face 2. It will be appreciated that the gap may be the same as for the front face 1 in other embodiments, but that a thinner gap may be acceptable as still providing a handle without needing to accommodate / protect any sockets. A handle may therefore also be provided at the rear of the power unit 100. In other embodiments, each grab-bar 150 may contact the body 110 along the height of the rear face 2, and so no spacing between the grab-bar 150 and the body 110 may be provided on the rear face 2. In the embodiment shown, the grab-bars 150 are symmetrical - in other embodiments, one grab-bar 150a may contact the rear face 2 and the other grab-bar 150b may be spaced from the rear face 2, or they may be spaced by different amounts. In the embodiment shown in Figures 1 and 2, each grab-bar 150 forms a single, separate, loop, each loop encircling one side of the body 110 - each grab-bar 150 therefore extends around the complete perimeter of the respective side of the body 110. The grab-bars 150 are at least substantially identical in this embodiment. In alternative embodiments, the grab-bars 150 may be conjoined and may cross or meet, for example across the rear face 2, so providing two conjoined loops (e.g. in the form of a bent figure of eight, or with a portion of the bar 150 extending horizontally across the rear face 2 instead of vertically across it, so as to meet the other bar). The grab-bars 150 may be made of metal, and optionally may be hollow metal tubes or bars. Other materials may be used in other embodiments - it will be appreciated that the grab-bars should be strong enough to allow the portable power unit 100 to be lifted by means of the grabbars 150, and to provide some protection for the body 110. The body 110 is arranged to removably receive a battery module 200. The body 110 has an internal cavity arranged to receive the battery module 200. In various embodiments, such as that shown in Figures 1 and 2, the body 110 comprises a hatch 114 which is arranged to be openable to allow a battery module 200 to be inserted and removed, as indicated by the arrow, A, in Figure 2. The hatch 114 forms a portion of the front face 1 of the body 110, and is hinged to the upper face 5 such that the hatch 114 opens upwards / moving past and between the grab bars in the implementation shown. The hatch 114 extends between the grab-bars 150 and does not overlap with the grab-bars 150. The battery module 200 is concealed under the flap / hatch 114 when the power unit 100 is in use. The grab-bars 150 may therefore shield the hatch 114 from impact when it is closed or near-closed. The body 110 comprises at least one socket, and optionally at least two sockets 112, 113. At least one socket 112, 113 is located on the front face 1 of the body 110. Plugs inserted into any socket 112, 113 on the front face may therefore be shielded from impact by the spaced grab-bars 150. The body 110 shown comprises two sockets on its front face. A first socket 112 on the front face 1 is a Type 2 charging socket 112 in the embodiment shown. The Type 2 charging socket 112 is the charging connector 112 of the embodiment shown in Figure 1. The IEC 62196 Type 2 connector is used for charging electric vehicles, mainly within Europe, and has been declared standard by the EU. The Type 2 socket 112 is therefore the Europe-wide, universal socket for charging electric cars. In other embodiments, a different standard electric vehicle charging socket may be provided, instead of, or as well as, a Type 2 charging socket 112, for example a Type 1, CCS, or CHAdeMo socket as currently known in the art, or a future standard electric vehicle charging socket. The power unit 100 may be charged via a cable and plug connected to the Type 2 charging socket 112. In still further embodiments, for example that described below with respect to Figure 4, the electric vehicle standard charging socket 112 may be replaced with a connector 112 of a different type - for example a retractable cable 112a or socket which may then be connected to a hub or dock 400 comprising a standard electric vehicle charging socket 402. Turning back to the embodiment of Figures 1 and 2, this charging socket 112 may allow a battery module 200 mounted within the body 110 to be charged from a standard electric vehicle charger. This may allow a user to meter unit charging separately from household energy use. A second socket 113 on the front face 1 is an output socket 113, and, in the implementation shown in Figures 1 and 2, is a three-pin mains socket arranged to receive a domestic plug, as is standard across the United Kingdom. In other implementations, the output socket 113 may be different - for example it may be a Commando socket or a two-pin mains socket as used in the United States of America or Europe. In various implementations, the output socket 113 may be arranged to receive a domestic plug (e.g. Types A, B, C, D, E, F, F / G, G, H, I, J, K, L, M, N), or may be a Commando socket. The unit 100 of the embodiment pictured is arranged to output 230V AC through the three pin output socket 113. In various embodiments, the unit 100 may be arranged to output a different voltage, which may be AC or DC, e.g. 240V AC, 110 V AC, or 110 V DC. Multiple output sockets 113 may be provided in some implementations - for example, the unit 100 may have two 110 V commando sockets. The received battery module 200 can therefore be charged via the Type 2 charging socket 112 and discharged via the output socket 113. The body 110 comprises connectors and circuitry (not shown) arranged to contact terminals of the battery module 200 and to deliver power between the sockets 112, 113 and the battery module 200. The circuitry may comprise one or more safety cut-offs, for example fuses, sensors, monitoring systems, and / or similar, and may be arranged to cut off power drawn from the unit 100 or power being fed to the unit 110 (or to / from one battery module 200 within the unit 100) if set limits are exceeded. In particular, the body 110 may comprise an inverter, monitoring system, and controller to meet the standards for a Type 2 charging socket (or whichever socket type is applicable in other embodiments). Monitoring and control may be provided by a single processing unit in some embodiments, or may be distributed (e.g. with some processing performed in the cloud, and communications between the unit and the cloud) in other embodiments. The power unit 100 may comprise one or more temperature sensors, and / or each battery module 200 may comprise one or more temperature sensors. The monitoring system may be arranged to receive temperature data from one or more temperature sensors of the body 110 itself, and / or of a docked battery module 200, and to provide an alert and / or cut power flows if temperature exceeds a set threshold. The monitoring system may monitor a state of charge of each / a docked battery module 200 and provide an alert and / or cut or change power flows if the state of charge drops below, or rises above, a set threshold. Similarly, current, and / or voltage may be monitored for the unit 100 as a whole, and / or for each battery module 200 independently, and action may be taken automatically if set conditions occur. Various embodiments may incorporate any suitable battery safety sensing equipment into the monitoring system - for example sensors for Volatile Organic compounds (VOCs) and / or for other gases such as hydrogen which may be released if a battery malfunctions. Sensors such as accelerometers, humidity, temperature, and / or pressure sensors may be used to monitor conditions within the power unit, and also may be used to monitor an environment to which the power unit 100 is exposed, and how it is treated - data from such sensors may be utilised for service plans - e.g. a large shock loading sensed by an accelerometer can be used to flag the afflicted power unit 100 for service at a depot, etc. Further, parameters sensed by the monitoring system may be used to trigger real-time changes, such as sensing VOC’s - which indicates a damaged / venting battery - triggering a shut-down of the power unit 100, and potentially providing an audible and / or visual alert, and / or sending an alert message to a remote device (such as a user or manager’s personal electronic device, or a central server). It will be appreciated that power units 100 used on construction sites and in other scenarios are likely to be treated quite roughly, and that units carried by hand may be dropped, so enhanced battery safety systems may be desirable despite the potentially-increased weight and / or cost. Isolation monitoring may also be performed, and / or each battery may have interlocks and / or similar to detect whether or not it has been properly connected - the monitoring system may be arranged to provide an alert and / or disable all or part of the power unit 100 if not (for example, isolating one battery module 200 from the rest of the unit). In embodiments in which multiple battery modules 200 are received in a single power unit 100 simultaneously, the monitoring and control system may be arranged to control power fed to, or drawn from, each battery module 200 independently, for example as described in the applicant’s GB patent application GB 2309183.8 entitled “Independent Battery Apparatus”. One battery module 200 may therefore be used to recharge another, redistributing power within the unit 100, in some such embodiments. In some embodiments, the monitoring system and / or controller may communicate with a remote device or server, or the cloud - for example using standard “Internet of Things” communication options such as MQTT protocol - so as to facilitate remote monitoring and / or control of the power unit 100, and / or to outsource processing. For example, a construction site worker may receive a notification on a smartphone to flag that a particular power unit 100 is running low on power and may fetch a new battery module 200 and insert that into the particular power unit 100 before the power is exhausted. In embodiments in which the output power is AC power, the circuitry comprises one or more DC-AC inverters arranged to convert the DC power from the battery module 200 to AC power. The DC-AC inverter may be capable of delivering at least 4 kW continuous power. In embodiments in which the output power is DC power, one or more converters may be provided to adjust the power output from the battery module(s) 200 as appropriate. In embodiments in which the input power is AC power, the circuitry comprises one or more converters arranged to convert the AC power from an external connected source (e.g. the grid) to DC power for the battery module 200. In embodiments in which the input power is DC power, the DC input power may be adjusted to suit the one or more battery modules 200 to be charged. Less power conversion equipment may be needed within the unit 100 when it is arranged to be charged with DC power. In various embodiments including that shown in Figures 1 and 2, each socket 112, 113 is provided with a corresponding socket cover 112a, 113a, the socket cover being arranged to cover and protect the respective socket 112, 113 when that socket is not in use, and to be moved out of the way to allow a plug to be inserted into the socket 112, 113 in use. The covers 112a, 113a take the form of hinged flaps in the embodiment pictured - it will be appreciated that any suitable cover design may be used in other embodiments, for example a sliding cover or a removable cover connected to the body by a string, wire, or strip of material. The sockets 112, 113 and hatch 114 are all located on a front face 1 of the body 110 in the embodiment pictured. The spaced grab-bars 150 may therefore shield and protect the hatch 114 and sockets 112, 113, which may otherwise be the portions of the body’s surface most vulnerable to damage from knocks. In particular, if the unit 100 is put down with its front face 1 towards the ground, or pushed into a wall with the front face towards the wall, the grab-bars 150 may prevent contact between the sockets 112, 113 (or covers 112a, 113a where present) or hatch 114 and the floor or wall. The spacing, d, and grab-bar width may also be selected to be sufficient to shield any plug in either socket from direct impact in the same way. A cable from an inserted plug may be threaded through a grab-bar to protect it in some embodiments, for example if the plug is small enough to fit therethrough. The sockets 112, 113 are adjacent to each other and below the hatch 114 in the embodiment pictured, but may be differently located in other embodiments. In alternative embodiments, the arrangement may be different - for example, the hatch 114 may be on the rear face 2 and the sockets on the front face 1, or vice versa, or one or more sockets 112, 113 or the hatch 114 may be provided on other faces 3, 4, 5, 6 of the body 110. The portable power unit 100 of various embodiments including that shown in Figures 1 and 2 further comprises a power switch or button 115 arranged to switch the unit 100 on or off. Multiple control buttons 115 may be provided in other embodiments. In the example pictured, the power button 115 is located centrally with respect to the width of the front face 1, below the hatch 114 and between the sockets 112, 113. The button(s) 115 or other controls may be differently located in other implementations. The portable power unit 100 of various embodiments including that shown in Figures 1 and 2 further comprises a power level indicator 116, for example in the form of an LED indicator 116. The power level indicator 116 is arranged to provide a visual indication of the state of charge of the battery module 200. For example, one or more LEDs may go out, or change from green to red, or green to amber to red, as the battery power is depleted in use. In the embodiment shown, the indicator 116 is provided as a line on one, or both, side faces 3, 4 of the body 110. The indicator 116 may be differently positioned, and / or differently shaped, in other embodiments - for example, it may be on the front face 1, optionally below the sockets 112, 113, between the sockets and the hatch 114, or on one side of the front face. The indicator 116 may lie fully within the body 110, for example behind a transparent portion of the adjacent face of the body 110, for protection. In the embodiment shown in Figures 1 and 2, the portable power unit 100 has a vertical plane of mirror symmetry bisecting, and perpendicular to, the front face 1 - the general shape of the right side of the unit 100 is effectively a reflection of the left side of the unit, with the only difference being socket type 112, 113 (which may not be apparent when the socket covers 112a, 113a are closed, although the covers may be shaped or marked to indicate the socket type in some embodiments). Shape may differ in other embodiments, and may not be symmetrical. In the embodiment shown in Figures 1 and 2, the body 110 is arranged to receive a single battery module 200. In other embodiments, the body 110 may be arranged to receive multiple battery modules 200 (for example, two to five modules 200), and may have multiple hatches 114 (or a single, larger, hatch) accordingly. In embodiments in which the body 110 can receive multiple battery modules 200, a number of battery modules 200 to be inserted may be decided based on load requirements - one or more battery modules 200 may therefore be left in a van or other location when not needed, so lightening the load for a user. Similarly, the removability of the battery modules 200 means that these modules may be carried separately so reducing the amount a user needs to carry at once even if all modules 200 are needed. Flexibility and portability are therefore improved as compared to monolithic prior art units. Appropriate circuitry is provided by the body 110 to connect the one or more received battery modules 200 to the input / charging connector(s) 112 and output socket(s) 113, as well as optionally providing connections to one or more control and / or monitoring systems. Data connections may be provided as well as electrical connections, for example so as to allow an integral monitoring system of a battery module 200 to communicate with the power unit 100, and / or to allow the power unit 100 or a battery module docked therein to communicate with a remote device / server / the cloud. In some embodiments, the portable power unit 100 may be arranged to clip, or otherwise connect, to a second portable power unit 100, so allowing a larger power bank to be built from multiple, individually-portable, power units 100. An electronic controller of a “master” power unit 100 - generally the unit for which the output socket 113 is in use - may balance the load between the multiple connected portable power units 100. A user interface may be provided to allow a user to nominate one power unit 100 of the coupled set as a “master” power unit 100, or control processing may be remote (e.g. in the cloud), with instructions relayed back to each power unit 100. Up to five or ten portable power units 100 may be coupled together in some embodiments. Coupling units 100 together may allow the overall system to provide at least one of a higher power output, and a longer duration continuous output, than could be obtained from each unit 100 individually. A controller of one of the power units 100, or a remote controller, may balance loads between the power units. Each power unit’s controller or monitoring system may provide feedback on a current state of charge of, and power output from, the respective unit 100. In the embodiment being described, the battery module 200 is a 2 kWh battery module - i.e. it comprises one or more batteries which together provide 2 kWh of energy when fully-charged. More generally, each battery module 200 may have a capacity of 0.5 kWh to 5 kWh, 1 to 5 kWh, or 1 to 3 kWh. The battery module 200 may be charged in situ within the unit, e.g. via the Type 2 charging socket 112 when that is connected to a grid supply or other power supply, or may be removed from the unit 100 for charging. Figure 3 illustrates a separate charging hub 300 which may be used to charge the battery module 200 when it is removed from the portable power unit 100. The charging hub 300 comprises a dock 302 arranged to receive the battery module 200 and form an electrical connection with it, and a connecter 304 for connecting the hub 300 to an electricity supply -e.g. a mains supply. The connector 304 comprises a cable and standard domestic plug in the example pictured. In some embodiments, the hub 300 may be arranged to be charged from an electric vehicle, and may have a Type 2 connector 304 to permit connection to the vehicle’s battery, or any connector 304 suitable for connecting to an AC charging point installed in the vehicle. The hub 300 of the implementation pictured comprises an AC-DC rectifier capable of delivering at least 500 W of DC power to the battery module 200. Other power electronics may be used in other embodiments, as appropriate for the power source and the power unit 100 to be charged. Locating the power electronics for charging within the hub 300 rather than within the module 200 may help in reducing module weight. The charging hub 300 can be configured to charge and house additional battery modules 200 to be swapped into the portable unit 100. In some embodiments, the hub 300 may comprise a plurality of docks 302, and may be arranged to charge multiple battery modules 200 concurrently. The charging hub 300 may be able to receive more battery modules 200 than the power unit 100 can, in some embodiments. The battery module 200 of the example pictured is substantially cuboid in shape, with a handle 202 extending from its front end - this handle 202 may be used for lifting and carrying the battery module 200, and for guiding it through the hatch 114 / into the body 110 of the portable charging unit 100. In the implementation shown in Figure 3, the dock 302 is arranged to receive a rear end of the battery module 200, opposite to the front end 202. The electrical connections of the battery module 200 may therefore be located on or near a rear face of the battery module 200. It will be appreciated that keeping the electrical connections spaced from the handle 202 may improve safety and reduce the risk of damage to the connections / terminals. As such, in the implementation shown in Figures 1 and 2 - in which the handle 202 of the battery module 200 is nearest to the front face 1 of the body 110, which has the sockets 112, 113 and power control button 114 - electrical connections / circuitry may run along the length of the body 110, from its rear to its front, to connect the battery module 200 to the sockets 112, 113 etc. In other embodiments, the hatch 114 may be on the rear face 2 of the body 110, remote from the sockets 112, 113, and shorter electrical connections may therefore be sufficient. In the implementation shown in Figure 3, the dock 302 faces upward and the battery module 200 is lowered into the dock as indicated by the arrow B. The dock 302 is shallow compared to module length, and receives only a relatively small rear portion of the module 200. In other implementations, the dock 302 may be differently-oriented, and / or deeper, for example such that a battery module 200 is inserted fully within the dock 302 - the hub 300 may be larger than the battery module 200 in such embodiments. A power unit 100 and one or more battery modules 200 may be provided as a kit of parts. Optionally, a charging hub 300 may be provided as part of that kit of parts so as to allow battery modules 200 to be removed and recharged whilst the power unit 100 is still in use and not connected to a mains supply. Additionally or alternatively, a charging unit 400 as described below may be provided as part of the kit of parts. The battery module 200 is designed to have contacts / electrical connections which can interface with both the hub 300 and the power unit 100. Figure 4 shows an alternative embodiment 100a from the power unit 100 shown in Figures 1 and 2. To avoid repetition, the below discussion of the embodiment of Figure 4 focuses on differences between the two embodiments, with features otherwise generally being as described with respect to Figure 1. The portable power unit 100a of the embodiment of Figure 4 does not comprise an EV charging socket arranged to charge the portable power unit 100a. Instead, a different form of charging connector 112 arranged to provide power from a standard electric vehicle charging plug to the portable power unit 100a is provided. More specifically, the portable power unit 100a of the embodiment being described with respect to Figure 4 comprises a socket 112 arranged to have a cable 412 connected thereto, and is arranged to be used with a separate charging unit 400, which may be referred to as a charging hub 400. In the embodiment shown in Figure 4, the charging connector 112 is located on the rear surface 2 of the power unit 100. In other embodiments, the charging connector 112 may be located on the front surface 1 of the power unit 100. For example, in the embodiment shown in Figure 7, the charging connector 112 is on the front face, and may be, or be adjacent to, one of the frontface sockets 112, 113. By contrast, in Figure 4, the charging connector 112 is on the rear face, and the front face has two output sockets, with respective covers 113a, 113c. A cover may be provided to cover and protect the charging connector 112 when not in use. The grab-bars 150, and the spacing, d, of the grab-bars 150 from the surface on which the charging connector 112 is located, may serve to shield and protect the charging connector socket 112 and any plug mounted therein. The cable 412 of the embodiment shown is integral with / a part of the charging hub 400. In other embodiments, the cable may be a retractable cable provided as part of the portable charging unit 100 (and may be classed as a part of the charging connector 112), or may be detachable from both. The cable is arranged to transmit DC power from the charging hub 400 to the portable charging unit 100 in the embodiment being described. The charging hub 400 comprises an EV charging socket 402, which may be a Type 2 socket or any other standard EV charging socket. An EV charging cable is then connected to the hub 400 and used to provide power to the portable charging unit 100 via the hub 400. The portable power unit charging hub 400 may be arranged to deliver at least 500 W of DC power to the charging connector 112 of the portable power unit 100. The charging hub 400 may comprise an AC to DC converter / rectifier, in embodiments in which the EV charging socket 402 receives AC power. More generally, the charging hub 400 may comprise any suitable power electronics (e.g. one or more converters, inverters, and / or transformers) arranged to convert whatever power the charging hub 400 receives to a suitable form for direct charging of the portable power unit 100. As such, no power electronics / charging electronics may be required at the power unit 100 in association with the charging connector 112, so reducing the mass, and potentially also the volume, of the portable power unit 100. In some embodiments, AC-DC conversion may be performed by the hub 400, and any further power adjustment may be performed by the portable power unit 100. The power electronics may therefore be split between the two entities. The charging hub 400 is therefore physically separate from the portable power unit 100, and may be provided in a static location to which the potable power unit 100 is returned for charging. For example, the charging hub 400 may be wall-mounted in the vicinity of a grid connection, or may be located on or within a vehicle and powered by a battery of that vehicle (e.g. an electric vehicle battery, or simply a battery stored onboard a vehicle). In some embodiments, the charging hub 400 may comprise two sockets 402 such that two portable power units 100, or a portable power unit 100 and an electric vehicle, can be simultaneously charged from the same hub 400. More than two sockets 402 may be provided in some embodiments, although it will be appreciated that power electronics within the hub 400 may be required to prevent overloading of a grid, or other, connection to the hub 400. In such embodiments, the kit of parts may therefore include the portable power unit charging hub 400, in addition to, or instead of, the battery module charging hub 300. The battery modules 200 may therefore be charged in situ within the power unit 100, or separately. Figures 5 and 6 show perspective front and rear views of another portable power unit 100b, respectively. This portable power unit 100b is similar to that 100a shown in Figure 4, but without a rear charging socket. The rear face 2 of this portable power unit 100b comprises a ventilation grille 117 arranged to facilitate circulation of cooling air. This portable power unit 100b is shown in conjunction with a charging hub 400 in Figure 7. It will be appreciated that many different implementations are possible within the scope of the appended claims, and that the description of specific embodiments is provided by way of nonlimiting example only. For example, an additional handle or strap may be provided - e.g. in the centre of the top face of the unit 100 - in some embodiments, to facilitate lifting or carrying the portable power unit.

Claims

1. A portable power unit comprising:a body, the body having a mass of no more than 10 kg and being at least substantially cuboid in shape and comprising a front face comprising an output socket, a rear face opposing the front face, and upper, lower, left-side, and right-side faces extending between the front and rear faces, and a charging connector arranged to provide power from a standard electric vehicle charging plug to the portable power unit, the body being arranged to removably receive at least one battery module and comprising circuitry such that a received battery module can be charged via the charging connector and discharged via the output socket; anda pair of grab-bars, the grab-bars each extending around one side perimeter of the body such that each grab bar contacts the upper and lower faces of the body along the full length of the body and at a respective side of the body, and extends beyond the front face such that there is a space of at least 1.2 cm between the front face and the portion of each grab-bar extending thereacross.

2. The portable power unit of Claim 1, wherein either:(i) the charging connector comprises a standard electric vehicle charging socket, such as a Type 2 charging socket; or(ii) the charging connector is arranged to be connected to a separate charging unit comprising a standard electric vehicle charging socket.

3. The portable power unit of Claim 1 or Claim 2, wherein the output socket is arranged to provide at least one of the following:(i) 220 V, 230 V, or 240 V AC output; and(ii) 4 kW output power.

4. The portable power unit of any preceding claim, wherein the output socket is either a socket for a three-pin domestic plug or a Commando socket.

5. The portable power unit of any preceding claim, wherein the space between the front face and the portion of each grab-bar extending thereacross is at least 2 cm wide, and optionally at least 3-4 cm wide.

6. The portable power unit of any preceding claim, wherein the grab-bars each extend beyond the rear face such that there is a space of at least 1.2 cm between the rear face and the portion of each grab-bar extending thereacross.

7. The portable power unit of any preceding claim, further comprising a battery hatch arranged to be openable so as to allow at least one battery module to be inserted and removed.

8. The portable power unit of Claim 7, wherein the battery hatch is located in the front face.

9. The portable power unit of any preceding claim, further comprising a cover for each socket.

10. The portable power unit of any preceding claim, further comprising a power indicator arranged to visibly display an indication of remaining power available.

11. The portable power unit of any preceding claim, wherein the body comprises a plurality of output sockets, and optionally wherein the body comprises two 110 V Commando sockets.

12. The portable power unit of any preceding claim, wherein the body is arranged to receive only a single battery module.

13. The portable power unit of any of Claims 1 to 12, wherein the body is arranged to receive a plurality of battery modules, and optionally comprises a separate hatch for each battery module to be received.

14. The portable power unit of any preceding claim, wherein the body comprises an inverter, arranged to convert DC power from a received battery module to AC power for the output socket.

15. The portable power unit of any preceding claim, wherein the body comprises a monitoring system comprising one or more gas sensors including a Volatile Organic Compound sensor, the portable power unit being arranged to cut power flow to or from a received battery module in response to gas detection by the monitoring system.

16. The portable power unit of any preceding claim, wherein the body comprises a controller arranged to control energy flows between the output socket, charging connector, and one or more received battery modules.

17. The portable power unit of any preceding claim, wherein the grab-bars either:(i) extend further outward than the body along the sides of the body; or(ii) align with the sides of the body such that an outer edge of each grab-bar is coplanar with its respective side of the body.

18. The portable power unit of any preceding claim, wherein the total mass of the body and the grab-bars is no more than 10 kg.

19. The portable power unit of any preceding claim, further comprising the at least one battery module.

20. The portable power unit of Claim 19, wherein the or each battery module has a mass of no more than 12 kg, and optionally no more than 9 kg.

21. A kit of parts comprises:a portable power unit as defined in any preceding claim; anda plurality of battery modules arranged to be removably received within the portable power unit.

22. The kit of parts of Claim 21, further comprising a battery module charging hub comprising a dock arranged to removably receive at least one battery module of the plurality of battery modules when that battery module is not within the portable power unit, and to provide power thereto.

23. The kit of parts of Claim 21 or Claim 22, further comprising a portable power unit charging hub, the hub comprising a standard electric vehicle charging socket, and wherein the hub is arranged to be connected to the charging connector so as to supply power to the portable power unit.

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