Charger

Abstract

The present disclosure relates to a charger 1 for a battery operated system configured to charge a battery pack 21, the charger comprising a housing 3 and a charging socket 5 in the housing for receiving a battery pack. Charging electronics provide direct current to an electrical connector 7 associated with the charging socket for charging the battery pack. A fan arrangement 9 is provided for forced cooling of the battery pack during charging. The housing 3 comprises a fan compartment 11 surrounding the fan 9 and an electronics compartment 13 surrounding the charging electronics. The fan compartment 11 and the electronics compartment 13 are at least separated by a wall 15.

Description

[Technical field]

[0001] The present disclosure relates to a charger for a battery-operated system configured to charge a battery pack, the charger comprising a housing, a charging socket in the housing for receiving the battery pack, charging electronics configured to provide direct current to an electrical connector associated with the charging socket for charging the battery pack, and a fan arrangement for forced cooling of the battery pack during charging. [Background technology]

[0002] Such chargers are widely used for charging battery packs for battery-operated tools. One problem with such chargers is how to improve their safety and reliability at a reasonable cost. Summary of the Invention [Problem to be solved by the invention]

[0003] One object of the present disclosure is therefore to provide a charger with improved safety and reliability. [Means for solving the problem]

[0004] Said object is achieved by a charger as defined in claim 1. More precisely, in a charger of the first mentioned kind, the housing comprises a fan compartment surrounding the fan and an electronics compartment surrounding the charging electronics, the fan compartment and the electronics compartment being separated by at least a wall. Thereby, the fan arrangement is given its own space. Sometimes moisture may appear in the charging socket. For example, if a battery pack is used outdoors or in cold or frosty conditions and is brought indoors for charging, water from the ambient air may form condensation on the battery that drips into the charging socket. Although the fan arrangement needs to be connected in some way or other to the charging socket so as to be able to force-cool the battery pack, the charging electronics are protected from moisture in an improved way, thanks to the wall between the fan compartment and the electronics department or the like. This provides a better isolation and therefore improved safety and reliability.

[0005] The fan compartment comprises an air inlet and an air outlet, typically the air outlet of the fan compartment may be connected to a charging socket. The air inlet and air outlet may be oriented substantially vertically when the charger is placed on a horizontal surface, which provides some protection to the inlet and outlet from, for example, water droplets coming from above.

[0006] The charger includes a drain in the charging socket that is located lower than the air outlet of the fan compartment when the charger is placed on a horizontal surface, to prevent any moisture that collects in the charging socket from entering the fan compartment. The drain may be located near the electrical connector.

[0007] The present disclosure further contemplates a charger for a battery-operated system configured to charge a battery pack, the charger comprising a housing, a charging socket in the housing for receiving the battery pack, and charging electronics configured to provide direct current to an electrical connector associated with the charging socket to charge the battery pack. The housing comprises an electronics compartment surrounding the charging electronics, the electronics compartment being surrounded by a set of walls, one of which comprises a cooling flange, allowing both a protected and sealed electronics compartment and efficient heat transfer from the compartment.

[0008] Typically, the cooling flange is made of aluminium and the other wall may be at least partially made of plastic. A gasket may be provided between the cooling flange and the other wall.

[0009] The cooling flange may be disposed in a cooling channel, with an inlet and an outlet of the cooling channel disposed on a bottom side of the charger. The housing may include a fan compartment enclosing a fan for cooling the battery pack, and the fan compartment and the electronics compartment may be separated by at least a wall. [Brief description of the drawings]

[0010] [Figure 1] 1 illustrates a charger and a battery pack to be charged. [Figure 2A] 2 is a cross-sectional view of the charger of FIG. 1 with a battery pack inserted. [Figure 2B] 2 is a cross-sectional view of the charger of FIG. 1 with a battery pack inserted. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The present disclosure generally relates to a charger 1 in a battery-operated system, the charger being configured to charge a battery pack 21, as shown with an example in FIG.

[0012] Such a system may typically employ two or more such battery packs, but this is not required. Usually, one battery pack is in use in a tool (not shown) while the other is being charged. The present disclosure provides a charger 1 with improved reliability and safety.

[0013] 1, the charger 1 comprises a housing 3 and a charging socket 5 therein for receiving a battery pack 21. Typically, the charger comprises a power plug 23 adapted to be connected to an AC mains socket (not shown), and internal charging electronics (typically a rectifier and various control and communication circuitry) in an electronics compartment 13 adapted to convert received AC power and provide a DC charging current to an electrical connector 7 in the charging socket 5 for charging the battery pack 21.

[0014] Charging the battery pack 21 in such a manner, for example, generates heat in the cells in the battery pack, so that the temperature of the battery pack 21 is kept low to provide efficient, fast charging and avoid damage to the cells in the battery pack 21. To achieve such purpose, a fan arrangement 9 is provided for forced cooling of the battery pack 21 during charging. The fan arrangement 9 comprises a motor and a fan driven by the motor. The battery pack 21 may, for example, comprise an air inlet, an air outlet, and a channel extending therebetween to provide efficient cooling of the cells thereof, but it may also be considered to provide cooling by an external cooling flange and enhance the cooling effect by forced cooling.

[0015] The present disclosure provides improved safety and reliability of such chargers. Although the charger 1 is intended to be used indoors, usually but not exclusively, in dry conditions, this does not always mean that the charger can be kept dry. For example, if the battery pack 21 is used outdoors in cold or even frosty conditions, it may become very cold. Using the battery also means that the battery can generate some heat and be kept somewhat warm. However, it may have been a significant amount of time since the last use, and the battery pack 21 may be below 0° C. when brought indoors for charging. This means that condensation may form on the battery before it heats up from charging, and that the condensation may drip into the charging socket 5 of the charger 1. This may pose a risk of malfunction of the charging electronics if water gets into the charging electronics compartment 13.

[0016] In the present disclosure, such problems are eliminated or reduced by providing a housing 3 with a fan compartment 11. Such a fan compartment 11 surrounds the fan 9 and is to some extent separated from the electronics compartment 13 surrounding the charging electronics. The fan compartment 11 and the electronics compartment 13 may typically be separated by at least a wall 15. Thereby, the charging electronics can be protected from any moisture coming into contact with the fan arrangement 9. The fan arrangement 9 typically needs to be in contact with the charging socket 5 to be able to cool the battery pack 21 during charging. This is however not the case for the charging electronics. Therefore, by separating the fan compartment 11 from the electronics compartment 13, the isolation of the electronics compartment 13 and therefore the safety and reliability of the charger can be improved in a cost-effective manner. The fan arrangement 9 itself has a higher rating for moisture resistance and the lead-throughs for driving the fan and connecting to the DC connector 7 for the battery pack can be arranged watertight.

[0017] Typically, the fan compartment comprises an air inlet 17 and an air outlet 19 so as to be able to generate a flow through the fan compartment, but the fan compartment can also be open in various ways. Preferably, however, the fan compartment comprises an air outlet 19 which is connected to the charging socket 5 so as to achieve an efficient supply of air towards the battery pack. The air inlet 17 receives ambient air.

[0018] The inlet 17 and outlet 19 may be oriented vertically and extend at least in a plane that deviates by less than 10 degrees from the vertical when the charger is placed on a horizontal surface so that they are not directed to a greater extent than necessary at rain or materials such as dust coming from above. This provides some protection for the inlet and outlet from rain coming from above when placed outdoors. They may also point slightly downwards.

[0019] It may further be preferred to provide a drain 41 in the charging socket 5 to direct any water away from the charging socket 5. Such a drain 41 may be located lower than the air outlet 19 of the fan compartment to prevent any moisture that collects in the charging socket from entering the fan compartment 11 when the charger is placed on a horizontal surface. It may also be preferred to locate such a drain 41 adjacent to, or even more preferably between, the electrical connectors 7 of the charger. This also further keeps the electrical connectors drier.

[0020] Since the fan arrangement used to cool the battery pack is separate from the charging electronics, it may be preferable to arrange a separate cooling arrangement for the charging electronics that is not in direct contact with the charging socket 5. An example of such a cooling arrangement is shown in Figs. 2A and 2B, which show a cross-sectional view of the charger of Fig. 1. Such a cooling arrangement comprises a fan 31 that supplies ambient air from an inlet 35 at the bottom side of the charger housing 3, via a cooling flange 33, to an outlet 37 also at the bottom side thereof. The charger may rest on a number of legs 39 protruding from the bottom side of the housing, in order to provide an open space below the charger housing 3 by lifting the charger housing 3 to some extent when it is placed, for example, on a tabletop. It is advantageous to arrange the inlet 35 and the outlet 37 at the bottom side of the housing where they are protected, but this is not essential. For example, one or both may also be arranged, for example, on a side wall of the housing.

[0021] As mentioned, a cooling flange 33 may be provided in the airflow path to closely connect with the charger electronics. The present disclosure contemplates providing the electronics compartment 13 as a space formed by a set of walls 33, 41, one of which is provided by the cooling flange 33. The cooling flange 33 is typically made of extruded aluminum, for example, while the remaining electronics compartment walls may be provided in one or more pieces of injection molded plastic. A sealing device, for example comprising a silicone rubber gasket 43, may be optionally provided between the cooling flange and the remaining electronics compartment walls to provide a more watertight space.

[0022] With such an arrangement, the cooling flange 33 can serve a dual purpose of conducting away heat generated from the electronics compartment 13 and sealing the electronics compartment 13. While such an arrangement works very well in combination with a separate fan compartment, for example as described above, such a dual purpose cooling flange can also be used in chargers where the battery pack is passively cooled or where the battery pack includes its own internal cooling fan.

[0023] The present disclosure is not limited to the examples described above, which may be modified and replaced in various ways within the scope of the appended claims.

Claims

1. A charger (1) for a battery operated system configured to charge a battery pack, comprising: a housing (3); a charging socket (5) in said housing for receiving a battery pack (21); charging electronics configured to provide direct current to an electrical connector (7) associated with said charging socket for charging said battery pack; and a fan arrangement (9) for forced cooling of said battery pack during charging, said housing (3) including a fan compartment (11) surrounding said fan (9) and an electronics compartment (12) surrounding said charging electronics. a fan compartment (11) and an electronics compartment (13), the fan compartment (11) and the electronics compartment (13) being separated by at least a wall (15), the fan compartment (11) having an air inlet (17) and an air outlet (19), the air outlet (19) of the fan compartment connecting to the charging socket (5), the charger (1) having a drain (41) in the charging socket (5), the drain (41) being positioned lower than the air outlet (19) of the fan compartment when the charger is placed on a horizontal surface.

2. 2. The charger of claim 1, wherein the air inlet (17) is connected to ambient air.

3. 3. The charger of claim 1 or 2, wherein the air inlet (17) and the air outlet (19) are oriented substantially vertically when the charger is placed on a horizontal surface.

4. The charger according to any one of claims 1 to 3, wherein the drain (41) is located in the vicinity of the electrical connector (7).

5. A charger as described in any one of claims 1 to 4, wherein the electronic component compartment (13) is surrounded by a set of walls (41, 33), at least one of which is formed by a cooling flange (33).

6. 6. The charger of claim 5, wherein the cooling flange (33) is made of aluminum and the remaining wall (41) is at least partially made of plastic.

7. 7. The charger according to claim 5 or 6, wherein a gasket is provided between the cooling flange (33) and the remaining wall (41).

8. The charger according to any one of claims 5 to 7, wherein the cooling flange (33) is arranged in a cooling channel, the inlet (35) and outlet (37) of the cooling channel being arranged on a bottom side of the charger.

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