CN210608626U

CN210608626U - Device for monitoring the operation of a battery pack for a power tool

Info

Publication number: CN210608626U
Application number: CN201921866753.5U
Authority: CN
Inventors: 瑞恩茨·贝克; 吉尔特·恩幸
Original assignee: 7RDD Ltd
Current assignee: 7RDD Ltd
Priority date: 2019-04-15
Filing date: 2019-10-30
Publication date: 2020-05-22
Anticipated expiration: 2029-10-30
Also published as: GB201905285D0; GB2584760A; GB202003656D0; GB2584760B; DE202019104365U1

Abstract

The utility model provides a device for monitoring operation of electric tool battery group provides group battery and charging member thereof. The battery pack includes a plurality of battery cells and desirably includes a monitoring circuit that allows the charge level of the battery cells to be detected. According to the utility model discloses, when the charger part is connected to the group battery in order to charge to the battery cell, the charger part can not move, until having examined the operation of the control return circuit of group battery to, if confirm that the control return circuit operates correctly, then the charger part will move in order to charge to the battery cell of group battery, but, if do not detect the control return circuit and operate correctly, then prevent the charger part to charge to the battery cell until the control return circuit is repaiied thereby the correct operation. This therefore prevents the risk of performing the charging operation of the battery cells in an uncontrolled and potentially dangerous manner.

Description

Device for monitoring the operation of a battery pack for a power tool

Technical Field

The utility model relates to provide a monitored control system to provide the means of monitoring the safe operation of battery cell (power cell), this battery cell is typically the battery cell who is set up as a part of group battery pack (battery pack).

Background

Battery packs, such as those provided for providing electrical power for operating power tools, which at present most typically contain a series of lithium battery cells, need to have an error monitoring system in order to ensure safe operation of the battery cells in normal use situations when connected to the power tool. This need always exists, but now more stringent regulations for monitoring battery cells are developed due to the relatively high risk of fire found in the event of a lithium battery failure.

In the field of using battery cells for operating electric tools, a new standard, namely now available EN62841-1, has been developed. Typically, annex K of the standard sets new requirements for ensuring the safety of the battery/tool/charger system, and it is necessary to ensure that a charging failure in an abnormal state of charge of a battery cell does not lead to overcharging of a single battery element.

SUMMERY OF THE UTILITY MODEL

To achieve this, more sophisticated monitoring systems are considered to be necessary. However, it has been found that such more complex monitoring systems are too expensive to manufacture, and it is therefore an object of the present invention to provide a monitoring system having a desired degree of reliability while being more cost-effective.

In a first aspect of the present invention, there is provided a device for monitoring the operation of a battery pack for a power tool, the battery pack comprising a plurality of battery cells, the battery cells being interconnected so that the power tool can be electrically and mechanically connected to the battery pack from the battery pack to the power tool provides power, the device being provided with a monitoring circuit and a voltage monitoring integrated circuit, the monitoring circuit being for monitoring each battery cell of the battery pack, the voltage monitoring integrated circuit being for changing the monitoring circuit from a standby mode to an active mode.

Typically, a monitoring loop is used to allow monitoring of the individual cells of the battery pack.

In one embodiment, the device is configured to operate with a monopolar (1P (pole)) battery pack, while in another embodiment, the device is configured to be used with a bipolar (2P) battery pack.

In one embodiment, a charger for connection with a battery pack to charge battery cells in the battery pack initiates a check cycle in the battery pack, typically upon initial electrical connection with the battery pack.

In one embodiment, the check period is initiated by simulation of an excess or "too high" voltage condition to a degree sufficient for the voltage monitoring IC to detect it and enter an active mode from standby.

Typically, upon entering the active mode, the voltage monitoring IC triggers operation of the monitoring loop which, if operating correctly, signals a change in operating mode to the charger.

Typically, the charger will start a charging cycle if it receives the signal, because the charger knows that the monitoring system in the battery pack is working and will therefore monitor the charging of the battery cells.

However, if the charger receives no signal or a substitute signal indicating a component failure in the battery pack, the charger detects that the required monitoring loop is not working properly and will not perform charging of the battery cells in the battery pack.

According to the utility model discloses a device uses voltage monitoring IC and a plurality of extra parts jointly to play the effect of the required equipment that can operate of monitoring return circuit that is used for each battery cell of inspection before beginning to charge the battery cell in the group battery, and consequently use voltage monitoring IC's main function to carry out the self-checking function effectively. Typically, said battery pack therefore comprises a voltage monitoring IC and a monitoring loop in order to monitor the charging of the battery cells of the battery pack when supplied with power as a result of an in-operation charging cycle of a charger electrically connected to the terminals of the battery pack with which the battery cells are eventually connected, wherein, after the electrical connection of the charger and the battery pack, a checking cycle is first performed by the charger and the battery pack before any of said charging cycles.

Typically, the check cycle is performed before charging of the battery cells begins and is initiated by the charger in operation to simulate an excessive or "too high" voltage condition in the battery pack to a degree sufficient for the voltage monitoring IC to detect the excessive or "too high" voltage condition and, if operating properly, change from standby to active mode.

Typically, if functioning correctly and has changed to an active mode, the voltage monitoring IC triggers the operation of a monitoring loop which, if functioning correctly, sends a signal to the charger to indicate a correct change in the mode of operation, and if the charger receives said signal that the monitoring loop has changed the mode of operation, the charger will start a charging cycle, since the charger knows that the monitoring system in the battery pack is working and will therefore monitor the charging of the battery cells.

However, if the charger receives no signal or a substitute signal indicating a component failure in the battery pack, the charger detects that the required monitoring circuitry is not working properly and will not perform charging of the battery cells in the battery pack.

Drawings

The specific embodiments of the present invention will now be described.

FIG. 1 shows a system for use with a 1P/20V system;

FIG. 2 shows a monitoring system 2P/20V or 1P/40V using sequential triggering;

FIG. 3 shows a monitoring system 2P/20V or 1P/40V with simultaneous triggering; and

fig. 4 shows an assembly comprising a power tool, a battery pack and a charger according to an embodiment of the invention.

Detailed Description

Referring first to fig. 4, there is shown the power tool 2 connected to a battery pack 4, the battery pack 4 when connected allowing the power tool 2 to be provided with the necessary power to operate the power tool 2. This therefore allows the power tool to be used remotely from the main power supply and does not require a connection to the main power supply. Although the present invention is intended for use with a battery pack of the type that can be connected to a power tool, it should be understood that the present invention can be used with a battery pack of the type: the battery pack may be provided for use with other types of articles. The battery pack typically includes a protective housing having an external electrical connection 12 to allow power to be supplied from the external electrical connection 12 when connected to an electrical connection 16 of an item such as the power tool 2 or to the external electrical connection 12 when the battery pack is released from the power tool and connected to the battery charger 6 via a mechanical bond and an electrical connection via the connection 12 of the battery pack and the connection 14 of the charger, the connection 14 of the charger ultimately being connected to another power source such as a mains power source via the plug 10 and the cable 8.

The battery pack is provided therein with a plurality of battery cells electrically connected to each other to allow power to be supplied from the battery cells to the power tool when connected thereto, and to be charged when the battery pack is connected to the charging device. It is desirable that each cell have a substantially uniform charge level so that they can be uniformly discharged and then uniformly charged.

Referring now to fig. 1, then with the battery charger, battery pack and battery therein electrically connected but before the charging cycle begins, and thus at the beginning of the charging process, a detection cycle Q1 is initiated by the charger, with the result that the VC2 and VC3 inputs of the voltage monitoring IC will exceed predetermined threshold voltage levels. The voltage monitoring IC output will change and Q10 is enabled when operating correctly, and then the monitoring loop of the device should detect the condition and signal the charger to indicate such a change in condition, thereby confirming to the charger that the voltage monitoring IC and other components in the monitoring loop are operating correctly, and thus being able to start the charging cycle with monitoring as needed.

Principle in fig. 1: q1 is activated before charging is started. The VC2 input and the VC3 input of the inputs to the IC will then exceed the threshold voltage. The IC output will change and Q10 is enabled. It can then be confirmed whether other components are also working. To start the test loop at the beginning of the charging cycle, 12V is input to the NTC output. The software in the charger can start up 12V first, and then the charger will wait for the ID signal to change, which is an indication that all elements in the battery pack are working. The charger can then lower the 12V enable signal after the IC in the battery pack is about to reset and the loop is ready for the normal charging cycle.

To initiate a check cycle according to an embodiment of the present invention and prior to the start of the charging cycle, a 12V voltage is applied to the NTC output, and this is generated by control software in the charger, such that 12V is provided when first electrically connected to the power tool, then the charger will wait to receive a suitable response ID from the battery pack indicating that all elements in the battery pack are working correctly, at which point the charger stops providing the 12V supply and the voltage monitoring IC in the battery pack will reset (reset) to standby mode, and the charger, battery pack monitoring loop and battery unit are ready to provide and receive a normal charging cycle.

Referring now to fig. 2, there is shown another embodiment of the present invention, wherein a monitoring system according to the present invention is shown that can be used with either a Sequential trigger (Sequential trigger) 2P/20V system or a 1P/40V system.

Principle in fig. 2: when a 12V test signal is input to the NTC, both ICs will switch, and a 2 times 2k resistor will be in parallel, so 500 ohms. If there is a problem, only the zener diode will be able to be measured. If the IC is on and the FET is not, then 1000+100 ohms will be measured and this is different from 500 ohms when all elements are on.

In this embodiment, when a 12V test signal is provided from the charger to the NTC, then two voltage monitoring ICs are provided as in this embodiment which should both switch operating mode and so would be 2 times the 2k resistance in parallel so that 500 ohms can be expected to be measured when the IC of the battery pack and the monitoring loop are operating correctly, in which case a start signal would be sent to the charger, the 12V supply is stopped, the IC can be reset and the charging cycle can be started.

If the IC is not operating correctly, only the Zener (Zener) diode is measured, which will not provide the required 500 ohms, and therefore no start signal will be sent to the charger, and the charging cycle will not start. In another error case, if the voltage monitoring IC is operating correctly, but the FET is not, the measurement will be 1000+100 ohms and again be a value other than the required 500 ohms value, so no start signal will be sent to the charger and the charging cycle will not start.

Referring to fig. 3, which shows another embodiment, fig. 3 shows a 2P/20V or 1P/40V monitoring system with simultaneous triggering (SimultaneousTriggering) and in this embodiment when a 12V test signal is applied to the battery pack on the NTC, both voltage monitoring ICs will switch simultaneously and will be 2 times the 2k resistance in parallel so that again 500 ohms can be expected to be detected, and if so, a start signal is sent to the charger to indicate correct operation of the monitoring loop, the 12V supply is withdrawn, the ICs reset and the charging cycle begins. If a problem occurs, again like in figure 2, only the zener diode is measured, which will give an incorrect reading, as would be the case if the IC were operating but the FET were not, which will provide a measurement of 1000+100 ohms different from the required 500 ohm reading when all elements are operating correctly, so no start signal will be sent to the charger and the charging cycle will not start.

Principle in fig. 3: when a 12V test signal is input to the NTC then both ICs will switch simultaneously and 2 times the 2k resistors will be in parallel, thus 500 ohms. If a problem occurs, only the zener diode will be able to be measured. If the IC is on and the FET is not, then 1000+100 ohms will be measured and this is different from 500 ohms when all elements are on.

The described system and method thus provides the required improvement in the level of fail-safe monitoring and which can be detected to allow the overall charge level to be corrected, now allowing individual cells to be monitored in an efficient and safe manner as each cell should be independently controlled and monitored, which can be achieved using one or more of the voltage monitoring ICs described herein, and providing for the inspection of the monitoring system for each situation as part of an inspection cycle prior to the charging cycle.

Claims

1. An apparatus for monitoring operation of a battery pack for a power tool, the battery pack including a plurality of battery cells interconnected to supply power from the battery pack to the power tool when the power tool is electrically and mechanically connected to the battery pack, characterized in that a monitoring circuit for monitoring the battery cells of the battery pack and a voltage monitoring integrated circuit for changing the monitoring circuit from a standby to an active mode are provided in the apparatus.

2. An arrangement for monitoring the operation of a battery pack for a power tool according to claim 1, characterised in that the battery pack is charged using a charger component which can be connected to the battery pack and the connection of the charger component to the battery pack initiates a check period in the operation of the battery pack, the check period being initiated by a simulation of an excess or too high voltage supply which is of a sufficient extent for the voltage monitoring integrated circuit to detect and for the standby to enter an active mode.

3. The apparatus of claim 2 wherein upon entering the active mode, the voltage monitoring integrated circuit triggers operation of the monitoring circuit which, if operating properly, signals the charger component to indicate a change in operating mode.

4. An apparatus for monitoring the operation of a battery pack for a power tool as set forth in claim 3 wherein if the charger component receives the signal indicating that the monitoring loop has changed operating mode, the charger component will begin a charging cycle because the charger knows that the monitoring loop and the battery pack are working properly and will therefore monitor the charging of the battery cells.

5. An apparatus for monitoring the operation of a battery pack for a power tool as set forth in claim 3, wherein if the charger component receives no signal or a substitute signal indicating a component failure in the battery pack, the charger component detects that the required monitoring loop is not working properly and does not perform charging of the battery cells in the battery pack.