Lithium battery pack

Abstract

The invention discloses a lithium battery pack, which is used for supplying power for a controlled device, and comprises a lithium battery, a battery management system, a detection switch and a delaystart circuit. The detection switch is arranged in a charge and discharge interface of the lithium battery. The delay start circuit comprises a first switch, a second switch, a delay resistor and a start control unit. The delay resistor is a negative temperature coefficient resistor; the first switch is connected in series with the delay resistor to form a whole body, and the formed whole body isconnected in parallel with the second switch to form a start unit; the start unit is connected in series between the controlled device and the lithium battery; the start control unit is electrically connected with the first switch and the second switch; the start control unit receives the detection signal of the detection switch and outputs a control signal; and the first switch and the second switch are connected or disconnected according to the control signal. According to the lithium battery pack, the detection switch detects the working state of the lithium battery automatically, and the delay start circuit adjusts the start time of the controlled device according to the detection signal fed back by the detection switch, thereby ensuring safe start of the controlled device through start delay.

Description

technical field [0001] The invention relates to a lithium battery pack, in particular to a lithium battery pack with automatic detection and delayed start. Background technique [0002] One of the technical difficulties in replacing traditional lead-acid batteries with secondary lithium-ion batteries in the field of electric bicycles is that it is necessary to install over-current, over-charge and over-discharge protection circuits for secondary lithium-ion batteries to ensure the safe operation of the batteries. [0003] Since the discharge rate of the secondary lithium-ion battery is much greater than that of the lead-acid battery under the same voltage and capacity conditions, when the lead-acid battery is directly replaced by the lithium-ion battery, if the controller parameters of the battery management system are not adjusted accordingly, It often causes the current to be too large at the moment of power-on, which triggers the over-current protection, resulting in the ...

AI Technical Summary

Problems solved by technology

[0003] Since the discharge rate of the secondary lithium-ion battery is much greater than that of the lead-acid battery under the same voltage and capacity conditions, when the lead-acid battery is directly replaced by the lithium-ion battery, if the controller parameters of the battery management system are not adjusted accordingly, It often causes excessive current at the moment of power-on, which triggers over-current protection, resulting in failure to start normally

In addition, the output or charge and discharge ports of common batteries are normally closed, that is, the battery can be directly output and discharged, so it is easy to generate an arc when the battery is connected to the system. This not only poses a certain safety hazard, but also easily causes charging. Damage to the discharge port

However, due to the wide variety of electric bicycle controllers and motor systems, and different working conditions, it is extremely difficult to require the controller to be adjusted according to the actual situation to match the battery. It is extremely important to adapt the state of the electric bicycle lithium battery pack to the controller and motor system of different vehicles

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