A device for heating a vehicle battery

Abstract

The invention is a device (100) for heating a battery of vehicle. The battery is rectangular. The device comprises an elongated flexible body (107), a temperature sensor (112), and a heating arrangement inside the body. The body further comprises a first end part (117), a second end part (118), a first long side part (119), a second long side part (120) and a short side part (121). The heating arrangement comprises four heating elements (115a, 115b, 115c, 115d), and two heating elements are positioned in the first long side part and two heating elements are positioned in the second long side part, and the temperature sensor is positioned in the short side part. The device is configured to be set around the battery in such a way that the side parts are positioned on corresponding sides of the battery.

Description

[0001] A device for heating a vehicle battery The invention relates to a device for heating a battery of a vehicle, and the battery comprises a rectangular frame comprising two long sides of the battery, two short sides of the battery, a top side of the battery and a bottom side of the battery, and the battery further comprises six cell departments, and the device comprises an elongated flexible body, a temperature sensor, a heating arrangement inside the body, and a connection arrangement for connecting the device to a power source, the device further comprises a first end of the device, a second end of the device, an upper side of the device and a lower side of the device. BACKGROUND Vehicles need a battery or batteries as a source of electricity, which batteries are generally charged during driving or externally, such as in vehicles running on elec- tricity. The operation of the battery deteriorates as the temperature falls, which leads to a deteriorated charging capacity, and additionally it is less effective at giving and receiving current when cold. This is a problem in areas, where the temperature is during winter seasons significantly below the freezing point of water during long pe- riods. This is especially problematic in electric and hybrid vehicles, where the elec- tricity taken from the battery is used for moving the vehicle, which makes the use of electric vehicles more difficult in cold conditions. It is generally known in motor- driven vehicles that cold starting them in some cases in very low temperatures takes so much current from the battery that it would be necessary to drive the vehicle for almost an hour for the battery to regain the current it lost in the start-up. Over a short distance there is not time to regain this lost current, and the capacity of the battery slowly decreases. Additionally, the number of devices and systems consuming cur- rent in vehicles has grown and in cold conditions the charge level of the battery very easily falls. The battery cannot last long in cold conditions with such consumption. Sooner or later in such cases the battery empties and the vehicle does not start, even if the engine warmer has been on all night. The above-described phenomenon occurs both in batteries, where the electrolyte is some liquid, such as in lead batteries, and in so-called dry batteries, such as lithium- ion batteries. Particularly lithium-ion batteries are especially sensitive to tempera- tures, for which they are not adapted. Too high and too low temperatures shorten the life of the lithium-ion battery and other types of batteries. Additionally, too low temperatures weaken both batteries’ current output capacity and its current intake capacity. In liquid batteries too high temperatures can even cause boiling of the battery liquid and too low temperatures freezing of the battery liquid, if the charge level of the battery falls too low. Most standard car batteries contain six cells or cell departments that are situated in two rows (2 x 3) inside the plastic casing. The cell departments are physically sep- arated from each other. One construction of cell contains a lead dioxide plate and a lead plate. The temperature of a cell determines how well it can deliver power and how easily or if at all it can be charged. The weakest cell in the pack can just be the hottest or coldest cell. Hence, it is important to control the cell temperature within limits and control the temperature gradients across a cell and across a pack. This is most prominent with truck batteries, i.e. heavy vehicles. These vehicles are, for ex- ample, buses, trucks, tractors, heavy duty vehicles and such. Figures 1a and 1b show an example of a battery 101 suitable for heavy vehicles. These kind of batteries are mainly used for vehicles with combustion engines, but they can used for auxiliary batteries for electric vehicles. Figure 1a shows the battery as seen from above and Figure 1b shows the battery as seen from side. The battery 101 comprises a rectangular frame comprising two long sides 102a, 102b of the battery, two short sides 103a, 103b of the battery, a top side 104 of the battery and a bottom side 105 of the battery. The battery further comprises six cell departments 106a, 106b, 106c, 106d, 106e, 106f, that are in two rows (2 x 3) inside the frame. The cell departments comprise two group of outer cell departments: a first group 106a, 106d and a second group 106c, 106f, and two middle cell depart- ments 106b, 106e between said two outer cell department groups. It can be also defined that the battery comprises three cell departments on the long side of the battery, witch cell departments are middle department, and two outer cell depart- ments. Between the cell departments inside the battery are vertical walls 127 sepa- rating the cell departments. In this embodiment, sizes of the cell departments are identical. In this embodiment, the top side of the battery forms a cover part for the battery, the cover part extends over the long sides and the short sides, i.e. area of the cover part is bigger than the area of the bottom side. A battery heater is known from patent publication US 5994669, where a battery is installed into a box, which is open at the top, the walls of which have heating ele- ments. These heating elements get their energy from external alternating current or from direct current obtained from another battery. The battery heater has a timer, with which the heater can be switched to a higher effect for some time, for example just before the battery is used. The described battery heater requires empty space around the battery, so that it can be placed in the engine space. Additionally, the battery heater presented in the publication requires opening the engine space to adjust the timer. BRIEF DESCRIPTION The object of the invention is a solution that can significantly reduce the disad- vantages and drawbacks of the prior art. In particular, the object of the invention is a heater for a car battery that is constructed in such a way that heating is fast and controlled. The objects of the invention are attained with an arrangement that is characterised by what is stated in the independent patent claim. Some advantageous embodi- ments of the invention are disclosed in the dependent claims. The invention is a device for heating a battery of vehicle, such as a truck. The battery is rectangular and comprises six cell departments. The device comprises an elon- gated flexible body, a temperature sensor, and a heating arrangement inside the body. The device further comprises a first end part of the body, a second end part of the body, a first long side part of the body, a second long side part of the body and a short side part of the body. The heating arrangement comprises four heating elements, and two heating elements are positioned in the first long side part and two heating elements are positioned in the second long side part, and the temperature sensor is positioned in the short side part. The device is configured to be set around the battery in such a way that the side parts are positioned on corresponding sides of the battery. When reference is made in the text to the upper or the lower parts or respective directions such as front or rear, a situation is described in which the device accord- ing to the invention is in use, i.e. put on a battery, and the battery is in a normal using position. In one embodiment of the invention is a device for heating a battery of a vehicle, the battery comprises a rectangular frame comprising two long sides of the battery, two short sides of the battery, a top side of the battery and a bottom side of the battery, and the battery further comprises six cell departments. The device comprises an elongated flexible body, a temperature sensor, a heating arrangement inside the body, and a connection arrangement for connecting the device to a power source. The device further comprises a first end of the device, a second end of the device, an upper side of the device and a lower side of the device. The body comprises a first layer and a second layer, and the heating arrangement is between the first layer and the second layer, and the second layer is configured to be towards the battery when the device is in use. In one advantageous embodiment of the invention, the device further comprises a first end part of the body, a second end part of the body, a first long side part of the body, a second long side part of the body and a short side part of the body, and the first end part comprise the first end of the device and the second end part comprise the second end of the device. The first long side part and the second long side part are between the end parts and the short side part is between the long side parts. The heating arrangement comprises four heating ele- ments, and two heating elements are positioned in the first long side part and an- other two heating elements are positioned in the second long side part. The temper- ature sensor is positioned in the short side part. The device is configured to be set around the battery in such a way that the first long side part is on the long side of the battery, the second long side part is on another long side of the battery, the short side is on the short side of the battery, and the first end part and the second end part are on another short side of the battery. In one embodiment of the device, the first end part of the body and the second end part of the body are configured to overlap when the device is set around the battery, and said end parts are positioned on the short side of the battery which is opposite to the short side of the battery where the short side part of the body is positioned when the device is in use. In a second embodiment of the device, the device further comprises an attaching arrangement for attaching the device around the battery, and the attaching arrange- ment comprises two parts configured to attach each other for tightening the device. Positioning the attaching arrangement on the opposite side of the battery than the temperature sensor and the connection arrangement, significantly reduces the prob- ability of damaging these parts when placing the device in place around the battery. In a third embodiment of the device, one attaching arrangement part comprises at least one buckle, and another attaching arrangement part comprises at least one strap, and the strap is fixed to the body in such a way that the strap has one free end and a free part, and the free part of the strap comprise a velcro type fastening arrangement, and the said free end is configured go through the buckle and then the strap is fastened using the velcro type fastening arrangement. This kind of at- taching arrangement has been found very fast and reliable. The attaching of the device can be done even in ten seconds. In a fourth embodiment of the device, the device for heating further comprises two overheating thermostats and there is one overheating thermostat on the first long side part and another overheating thermostat on the second first long side part, and the overheating thermostats are configured to detect temperatures of the middle cell departments, and the overheating thermostats are between the heating elements of one long side part of the body. The overheating thermostats improve the safety of the device by preventing overheating. The middle cell departments are most prone to the overheating in the event of a fault. In a fifth embodiment of the device, the overheating thermostats are closer to the upper side of the device than to the lower side of the device. The inventor has found that this is the most optimal position for the overheating thermostats. In a sixth embodiment of the device, the overheating thermostats are configured to detect if a predetermined temperature is exceeded and if this event is occurred, to send an overheat signal. In a seventh embodiment of the device, the temperature sensor is closer to the up- per side of the device than to the lower side of the device, and in middle of the short side part. The inventor has found that this is the most optimal position for the tem- perature sensor. In an eighth embodiment of the device, the first layer comprises three first layer parts, and the first layer parts are separate objects before being attached to the second layer for forming the first layer, and the first layer parts each form one part of one of following: the first long side part of the body, the second long side part of the body and the short side part. This feature makes manufacturing the device eas- ier and provides seams in the body that helps using the device. In a ninth embodiment of the device, the body comprises an insulation layer, and the insulation layer is configured to cover the first layer at least partly. This feature enhances the heating process and prevents unwanted heating of parts of motor that are near the battery. In a tenth embodiment of the device, the insulation layer covers at least the first long side part of the body and the second long side part of the body. Improving insulation prevents heat leaks and thus saves energy. In an eleventh embodiment of the device, the insulation layer comprises insulation layer parts, and the insulation layer parts are separate objects before being attached to the first layer for forming the insulation layer. In a twelfth embodiment of the device, height of the device, i.e. distance between the upper side of the device and the lower side of the device is height of the battery or the height of the device is at maximum 10% smaller than the height of the battery. In a thirteenth embodiment of the device, the battery comprises three cell depart- ments on the long side of the battery, witch cell departments are middle cell depart- ment and two outer cell departments, and the heating elements are positioned in such a way that the heating element of one long side part covers significantly less the middle cell department than outer the cell department. The inventor has found that the middle cell departments are heated fastest and thus they need less heating input. In a fourteenth embodiment of the device, the first long side part of the body and the second long side part of the body are slightly longer than corresponding long side of the battery, the short side part of the body is slightly longer than the short side of the battery, and the first end part of the body and the second end part of the body are shorter than the short side of the battery. This has been found to be optimal structure for the structure of the device both for installation and use. An advantage of the invention is that it can be used to improve use reliability of a vehicle in cold conditions. The invention can further be used to improve the life ex- pectancy and operating reliability of a battery. The invention is especially beneficial for trucks and other heavy duty vehicle used in cold areas, but it can further be adapted for all kinds of vehicle batteries. An advantage of the invention is further that it can be used for producing a battery heater, which is simple and easy to install. The battery heater according to the in- vention further takes little space, whereby it can be installed also in batteries placed in tight spaces. With the battery heater according to the invention the production and installation costs can be made significantly lower than with previously known prod- ucts. An advantage is also that the battery heater according to the invention does not contain parts, which would require service or adjustment, which improves the com- fort of use and reduces costs. The invention further improves the safety of the battery heater by monitoring the temperature of the battery in a reliable way and by providing a battery heater, which has as few parts as possible, which reduces potentially dangerous fault situations. The safety of the device is also increased by the fact that all the components of the device can be closed inside the body of the device in a gas- and liquid-tight manner. The operating costs of the invention are significantly less than the operating costs of the known device for heating batteries. DESCRIPTIONS OF THE FIGURES In the following, the invention is described in detail. The description refers to the accompanying drawings, in which Figure 1a shows an example of a battery as seen from above, Figure 1b shows the battery of Figure 1a as seen from side, Figure 2 shows a device for heating a battery according to an embodiment, Figure 3 shows the device of Figure 2 attached to the battery as seen from side, Figure 4 shows the device of Figure 2 attached to the battery as seen from short side, Figure 5 shows a cross section of the device of Figure 2, and Figure 6 shows an exploded view of the device of Figure 2. DETAILED DESCRIPTION The embodiments in the following description are given as examples only. Though the description may refer to a certain embodiment or embodiments in several places, this does not mean that the reference would be directed towards only one described embodiment or that the described characteristic would be usable only in one described embodiment. The individual characteristics of two or more embodi- ments may be combined and new embodiments of the invention may thus be pro- vided. Figures 2 shows an example of a device 100 for heating a battery that is similar to the battery described in Figures 1a and 1b. The device is an elongated object that is essentially flat and thin. By thin it is meant here that the thickness of the device is small compared to other dimensions of the device such as height and length. Some parts of the device are transparent for making describing structure of the device clearer. The device 100 comprises an elongated flexible body 107, a temperature sensor 112, a heating arrangement inside the body, and a connection arrangement 113 for connecting the device to a power source. The device further comprises a first end 108 of the device, a second end 109 of the device, an upper side 110 of the device and a lower side 111 of the device. The height of the device is distance between the upper side 110 of the device and the lower side 111 of the device. The length of the device is distance between the first end 108 of the device and the second end 109 of the device. The device 100 further comprises a first end part 117 of the body, a second end part 118 of the body, a first long side part 119 of the body, a second long side part 120 of the body and a short side part 121 of the body. The first end part comprise the first end 108 of the device and the second end part comprise the second end 109 of the device. The first long side part and the second long side part are between the end parts, and the short side part is between the long side parts. This means that order of said parts is (starting from left as seen in Figure 2) the first end part, the first long side part, the short side part, the second long side part, and the second end part. The heating arrangement comprises four heating elements 115a, 115b, 115c, 115d. Two heating elements are positioned in the first long side part, and other two heating elements are positioned in the second long side part. The heating elements are square like flat objects inside the body of the device. The heating ar- rangement and other means the device needs for functioning (such as wiring) that are inside the body are called internal hardware. The body is formed in such a way that the internal hardware is securely sealed inside the body. The internal hardware is connected to a power source and an external control unit by the connection ar- rangement 113. For that purpose, the connection arrangement comprises parts that extend outside the body. For simplifying the structure of the device, the connection arrangement is positioned in the same short side part as the temperature sensor. In some embodiments, the first long side part 119 of the body and the second long side part 120 of the body are slightly longer than corresponding long side of the battery, and the short side part 121 of the body is slightly longer than the short side 103a, 103b of the battery, and the first end part 117 of the body and the second end part 118 of the body are shorter than another short side of the battery. The battery is configured in such a way that it comprises three cell departments on the long side of the battery, witch cell departments are middle cell department, and two outer cell departments. and the heating elements are positioned in such a way that one heating element of one long side part covers significantly less the middle cell department than outer the cell department. This means that one heating element extends from one outer cell department to the middle cell department when the de- vice is in use. There is clear gap between the heating elements on one long side part. The temperature sensor 112 is positioned in the short side part 121. In this embod- iment, the connection arrangement 113 is also positioned in the short side part. The device 100 is configured to be set around the battery in such a way that the first long side part 119 is on the long side of the battery, the second long side part 120 is on another long side of the battery (i.e. opposing side), the short side 121 is on the short side of the battery, and the first end part 117 and the second end part 118 are on another short side of the battery. In this embodiment, the first end part 117 of the body and the second end part 118 of the body are configured to overlap when the device is set around the battery and said end parts are positioned on the short side of the battery which is opposite to the short side of the battery where the short side part 121 of the body is positioned when the device is in use (i.e. wrapped around the battery). The device 100 further comprises an attaching arrangement 116a, 116b on oppos- ing ends (or near them) of the device for attaching the device (the body of the device) around the battery 101, and the attaching arrangement comprises two parts config- ured to attach each other for tightening the device. In this embodiment, one attach- ing arrangement part 116a comprises at least one buckle 122, and another attaching arrangement part 116b comprises at least one strap 123. The strap or straps are fixed to the body 107 in such a way that the strap has one free end and a free part, and the free part of the strap comprise a velcro type fastening arrangement, and the said free end is configured go through the buckle and then the strap is fastened using the velcro type fastening arrangement. In this embodiment, the device 100 further comprises two overheating thermostats 114a, 114b and there is one overheating thermostat on the first long side part 119 and another overheating thermostat on the second first long side part 120. The over- heating thermostats are configured to detect temperatures of the middle cell depart- ments. The overheating thermostats are positioned in such a way that they are be- tween the heating elements of one long side part of the body. Furthermore, the overheating thermostats are closer to the upper side 110 of the device than to the lower side 111 of the device. This means that the overheating thermostats are, when the device is in use, above the horizontal middle line of the middle cell departments. This have been found to be an optimal position for observing possible overheating of the battery. The overheating thermostats are configured to detect if a predeter- mined temperature is exceeded and if this event is occurred, to send an overheat signal to an external battery heater control unit. In some embodiments, the device comprise some arrangement to stop heating when the overheat signal is detected. Advantageously, the overheating thermostat is positioned in such a way that that distances to the surrounding heating elements are equal. The temperature sensor 112 is in middle of the short side part 121. The temperature sensor 112 is also closer to the upper side 110 of the device than to the lower side 111 of the device. The temperature sensor detects temperature of the battery. The detected temperature is used for controlling behaviour of the device, i.e. keeping the battery in a predetermined temperature of a temperature range. These can be varied depending on, for example, external temperature, charge of the battery or other conditions. The temperature is sent to the external battery heater control unit, which controls heating processes of the device. In this embodiment, the connection ar- rangement 113 is positioned in same area as the temperature sensor. The connec- tion arrangement comprises adapters, connectors and such for connecting the de- vice to the power source and the external battery heater control unit. In some em- bodiments, the device comprises some circuits or similar for internal automatic con- trol, for example preventing the battery overheating. Figure 3 shows an example of the device 100 when it is set around a battery 101. The battery is similar as was described in Figures 1a and 1b and it is seen from side. The battery comprises a top side 104, a bottom side 105, short sides 103a, 103b and a long side 102a. Another long side is not seen. Inside the battery is six cell departments. Three cell departments are positioned behind the long side 102a. These cell departments are two outer cell departments 106d, 106f and a middle cell department 106e between outer cell departments. The body of the device is wrapped around the battery 101 and tightened in its place by the attaching arrangement (not seen in Figure 3) in such a way that the first long side part of the body 119 covers the long side 102a of the battery. When the device attached in its place, the end parts (first end part of the body and the second part of the body) overlap at least partly. In this embodiment, the device is configured in such a way that sides of the body extend from the bottom side 105 to the top side 104. Because in this embodiment the top side forms a collar type structure on upper side of the battery and edges of the collar extends over the vertical (when the battery is in a use position) sides of the battery, the upper side of the device extends to the collar. In some embodiments, the height of the device (the distance between the upper side of the device and the lower side of the device) is at maximum 10% smaller than the height of the battery. The heating elements 115a, 115b are positioned inside the body of the device in such a way that edges of heating elements do not extend to the upper or lower side of the device. This means that height of the heating element is less than the height of the device. The device 100 is configured in such a way that there is two separated heating elements on both long sides of the battery when the device is in use. This counterintuitively provides an effect that the battery 101, and more specifically, the cell departments inside the battery are heated evenly, i.e. temperatures of the cell departments are practically same or differ inside a temperature range that is signif- icantly smaller than temperature ranges in batteries heated with conventional de- vices. This effect is enhanced by positioning the heating elements of one long side part of the body (the first long side part 119 of the body or the second long side part of the body) in such a way that one heating element covers significantly less the middle cell department than outer the cell department. In one embodiment, surface areas of either heating element covering one outer cell department 106d, 106f is larger than combined surface areas or both heating elements covering the middle cell department 106e. The overheating thermostat 114a is positioned between two heating elements 115a, 115b. Distances between the overheating thermostat and heating elements are equal. Figure 4 shows the device 100 set around the battery 101. The setup is same as in Figure 3 but now the short side part of the body 121 covering the short side of the battery 103b. On this short side the battery comprises two outer cell departments 106f, 106c. The temperature sensor 112 is positioned on a border line between said cell departments. In that case the measured temperature best corresponds to the overall temperature of the battery. In this embodiment, the connecting arrangement 113 is in vicinity of the temperature sensor. This makes the structure of the body of the device slightly easier to manufacture. In some embodiments, the connecting arrangement is placed differently. This is, for example, due to the motor space of a vehicle where the battery is positioned. Figure 5 shows a cross section of the device 100 and more specifically the body 107 of the device. The cross section is made to the first long side part of the body 119 in such a way that one heating element 115b is shown. The heating element is positioned between the upper side 110 and the lower side 111 in such a way that there is a clear distance between sides of the heating element and the sides of the device. The body 107 comprises two parts: a first layer 125 and a second layer 126. The heating element 115b is between said layers. Also, the overheating thermostats and the temperature sensor between said layers. Similarly wiring and other equipment (internal hardware parts) are placed there. The device is configured in such a way that the second layer is towards the battery when the device is in use. The first layer and the second layer are same material. In some embodiments, the material is sili- cone based. In some embodiments, the material comprises fiberglass for reinforce- ment purposes. In this embodiment, the body 107 comprises an insulation layer 124. The insulation layer is placed on an outer surface of the first layer 125. The material of the insula- tion layer is such that thermal conductivity is less than thermal conductivity of the first and second layers. In some embodiments, the material of the insulation layer is silicone foam or other porous material. Using silicone based material in the insula- tion layer simplifies fixing the insulation layer to the first layer if the material of the first layer is also silicone based. The insulation layer is for preventing heat transfer- ring outwards. Also, this prevents unnecessary heating of nearby motor parts when the device is in use in a vehicle comprising a heated battery. The insulation layers are used for covering at least the heating arrangements, i.e. the long side part of the body. In some embodiments, the short side part of the body and / or the end part of the body. Figure 5 shows an exploded view of the device 100. The device comprises the body 107, and the body comprises the first end part 117 of the body, the second end part 118 of the body, the first long side part 119 of the body, the second long side part 120 of the body and the short side part 121 of the body. The device further com- prises the temperature sensor 112, two overheat thermostats 114a, 144b and the heating arrangement comprising four heating elements 115a, 115b, 115c, 115d. The device also comprises the connecting arrangement 113. The body comprises the first layer 125 and the second layer 126. The temperature sensor, the overheat ther- mostats, the heating elements and the wiring between these hardware parts are between the first layer and the second layer. In this embodiment, the first layer co- vers the first long side part 119 of the body, the second long side part 120 of the body and the short side part 121 of the body. In this embodiment, the body 107 comprises the insulation layer 124. The insulation layer forms parts of the first long side part 119 of the body, the short side part 121 of the body, and the second long side part 120 of the body. The insulation layer covers said parts of the body, and it is attached to the first layer 125. In this embod- iment, the insulation layer does not cover the first end part 117 of the body and the second end part 118 of the body. Because the end parts are overlapping, the insu- lation is sufficient also in the battery areas the end parts are covering. For allowing connections between the wiring and the connection arrangement 113 the first layer 125 and the insulation layer 124 comprise holes, slits or similar ar- rangements. For making manufacturing and at the same time installation processes easier the first layer 125 comprises three parts 125a, 125b, 125c and the insulation layer 124 comprises three parts 124a, 124b, 124c. These parts are separate before attaching the layers together for forming the body 107 of the device. In this process the first layer parts are fixed to the second layer in such a way that the internal hardware parts are between the thus formed first layer and the second layer. The first layer and the second layer encapsulate the internal hardware between them. The first layer parts form together a continuous layer i.e. the first layer. Each first layer part corresponds to the body parts of the second layer. The first layer parts are approxi- mately same size as the body parts of the second layer they are positioned over. The insulation layer parts are dimensioned similarly and they are fixed over the first layer parts. In this embodiment, one part of the second layer, one first layer part and one insulation part form the first long side part 119 of the body. Another part of the second layer, another first layer part and another insulation part form the short side part 121 of the body. The second long side part 120 of the body is formed similarly from one part of the second layer and corresponding first layer part and insulation part. In this embodiment, the first layer 125 extends from a border between the first end part of the body 117 and the first long side part 119 of the body to a border between the second end part of the body 118 and the second long side part 120. Also, in this embodiment, the insulation layer 124 extends correspondingly. Although the first layer parts 125a, 125b, 125c are connected together there are seams in the first layer 125 between the first layer parts. These seams helps when the device 100 is bended around the battery. The body 107 is configured in such a way that the seams coincide with the corners of the battery when the device is in use i.e. set around the battery. The body 107 folds better at the seams and thus the installation of the device is easier. In some embodiments, there are similar seam between the insulation layer parts 124a, 124b, 124c. In some embodiments, the insulation layer parts are not connected together but they are slightly separated from each other. This makes folding the body around the battery even easier. Some advantageous embodiments of the device for heating according to the inven- tion have been described above. The invention is however not limited to the embod- iments described above, but the inventive idea can be applied in numerous ways within the scope of the claims.

[0002] Reference numbers Device 100 Battery 101 Long side of the battery 102a, 102b Short side of the battery 103a, 103b Top side of the battery 104 Bottom side of the battery 105 Cell departments of the battery 106a, 106b, 106c, 106d, 106e, 106f Body of the device 107 First end of the device 108 Second end of the device 109 Upper side of the device 110 Lower side of the device 111 Temperature sensor 112 Connecting arrangement 113 Overheating thermostat 114a, 114b Heating element 115a, 115b, 115c, 115d Attaching arrangement 116a, 116b First end part of the body 117 Second end part of the body 118 First long side part of the body 119 Second long side part of the body 120 Short side part of the body 121 Buckle 122 Strap 123 Insulation layer 124, 124a, 124b, 124c First layer 125, 125a, 125b, 125c Second layer 126 Wall 127

Claims

Patent claims 1. A device (100) for heating a vehicle battery (101), and the battery comprises a rectangular frame comprising two long sides (102a, 102b) of the battery, two short sides (103a, 103b) of the battery, a top side (104) of the battery and a bottom side (105) of the battery, and the battery further comprises six cell departments (106a, 106b, 106c, 106d, 106e, 106f), and there is three cell departments on the long side of the battery, which cell departments are middle department (106b, 106e) and two outer departments (106a, 106c, 106d, 106f), and the device comprises an elongated flexible body (107), a temperature sensor (112), a heating arrangement inside the body, and a connection arrangement (113) for connecting the device to a power source, the device further comprises a first end (108) of the device, a second end (109) of the device, an upper side (110) of the device and a lower side (111) of the device, and the body comprises a first layer (125, 125a, 125b, 125c) and a second layer (126), and the heating arrangement is between the first layer and the second layer, and the second layer is configured to be towards the battery when the device is in use, and the device further comprises a first end part (117) of the body, a sec- ond end part (118) of the body, a first long side part (119) of the body, a second long side part (120) of the body and a short side part (121) of the body, and the first end part comprise the first end of the device and the second end part comprise the sec- ond end of the device, and the first long side part and the second long side part are between the end parts and the short side part is between the long side parts, and characterised in that the heating arrangement comprises four heating elements (115a, 115b, 115c, 115d), and two heating elements are positioned in the first long side part and two heating elements are positioned in the second long side part, and the temperature sensor is positioned in the short side part, and the device is config- ured to be set around the battery in such a way that the first long side part is on the long side of the battery, the second long side part is on another long side of the battery, the short side part is on the short side of the battery, and the first end part and the second end part are on another short side of the battery, and the heating elements are positioned in such a way that one heating element extends from one outer cell department to the middle cell department when the device is in use, and there is a clear gap between the heating elements on one long side part.

2. The device (100) according to claim 1, characterised in that the first end part (117) of the body and the second end part (118) of the body are configured tooverlap when the device is set around the battery (101), and said end parts are positioned on the short side of the battery (103a, 103b) which is opposite to the short side of the battery where the short side part (121) of the body is positioned when the device is in use.

3. The device (100) according to claims 1 or 2, characterised in that the device further comprises an attaching arrangement (116a, 116b) for attaching the device around the battery (101), and the attaching arrangement comprises two parts con- figured to attach each other for tightening the device.

4. The device (100) according to claim 3, characterised in that one attaching arrangement part (116a) comprises at least one buckle (122), and another attaching arrangement part (116b) comprises at least one strap (123), and the strap is fixed to the body (107) in such a way that the strap has one free end and a free part, and the free part of the strap comprise a velcro type fastening arrangement, and the said free end is configured go through the buckle and then the strap is fastened using the velcro type fastening arrangement.

5. The device (100) according to any of claims 1 to 4, characterised in that the device for heating further comprises two overheating thermostats (114a, 114b) and there is one overheating thermostat on the first long side part (119) and another overheating thermostat on the second first long side part (120), and the overheating thermostats are configured to detect temperatures of the middle cell departments (106b, 106e), and the overheating thermostats (114a, 114b) are between the heat- ing elements (115a, 115b, 115c, 115d).

6. The device (100) according to claim 5, characterised in that the overheating thermostats (114a, 114b) are closer to the upper side (110) of the device than to the lower side (111) of the device.

7. The device (100) according to claim 5 or 6, characterised in that the over- heating thermostats (114a, 114b) are configured to detect if a predetermined tem- perature is exceeded and if this event is occurred, to send an overheat signal.

8. The device (100) according to any of claims 1 to 7, characterised in that the temperature sensor (112) is closer to the upper side (110) of the device than to the lower side (111) of the device, and in middle of the short side part (121).

9. The device (100) according to any of claims 1 to 8, characterised in that the first layer (125) comprises three first layer parts (125a, 125b, 125c), and the first layer parts are separate objects before being attached to the second layer for form- ing the first layer, and the first layer parts each form one part of one of following: the first long side part (119) of the body, the second long side part (120) of the body and the short side part (121).

10. The device (100) according to any of claims 1 to 9, characterised in that the body (107) comprises an insulation layer (124), and the insulation layer is configured to cover the first layer (125, 125a, 125b, 125c) at least partly.

11. The device (100) according to claim 10, characterised in that the insulation layer covers at least the first long side part (119) of the body and the second long side part (120) of the body.

12. The device (100) according to claim 10 or 11, characterised in that the insu- lation layer (124) comprises insulation layer parts (124a, 124b, 124c), and the insu- lation layer parts are separate objects before being attached to the first layer for forming the insulation layer.

13. The device (100) according to any of claims 1 to 12, characterised in that height of the device, i.e. distance between the upper side (110) of the device and the lower side (111) of the device is height of the battery (101) or the height of the device is at maximum 10% smaller than the height of the battery.

14. The device (100) according to any of claims 1 to 13, characterised in that the heating element of one long side part (119, 120) covers significantly less the middle cell department (106b, 106e) than outer the cell department (106a, 106c, 106d, 106f).

15. The device (100) according to any of claims 1 to 14, characterised in that the first long side part (119) of the body and the second long side part (120) of the body are slightly longer than corresponding long side (102a, 102b) of the battery, the short side part (121) of the body is slightly longer than the short side (103a, 103b) of the battery, and the first end part (117) of the body and the second end part (118) of the body are shorter than the short side of the battery.

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