Battery pack circuit and battery pack heating method

Abstract

The invention discloses a battery pack circuit and a battery pack heating method. The circuit comprises a battery pack, a bidirectional buck-boost switch circuit, and a controller, wherein the batterypack comprises at least two battery units; the bidirectional buck-boost switch circuit is electrically connected between any two battery units through a first input / output end and a second input / output end which are mutually input and output ends; and the controller is electrically connected with the bidirectional buck-boost switch circuit, and is used for controlling the voltage conversion of the bidirectional buck-boost switch circuit is enabled or not according to the temperature of the battery pack, controlling whether the current voltage conversion of the bidirectional buck-boost switchcircuit is a boost voltage conversion or a buck voltage conversion, and controlling the input and output directions of the voltage conversion. When the temperature of the battery pack is lower than apredetermined low-temperature threshold, the technical scheme can utilize mutual charging and discharging of each battery unit in the battery pack to heat the batteries, so that the temperature of thebattery pack is increased.

Description

technical field [0001] The invention relates to the field of battery packs, in particular to a battery pack circuit and a battery pack heating method. Background technique [0002] The discharge capacity of lithium-ion batteries is significantly reduced at low temperatures. For example, the current national standard stipulates that the lower limit temperature of the discharge of lithium-ion batteries is not lower than -20°C. [0003] In order to improve the discharge performance of the battery, when the battery temperature is lower than the predetermined lower limit temperature, the battery temperature needs to be raised. At present, the common lithium battery heating method on the market is to heat through an external heating resistor. [0004] The disadvantage of this heating method in the prior art is that the heating is uneven from the outside to the inside; in addition, the use of the prior art requires multiple additional heat sheets to be attached to the outer periph...

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Problems solved by technology

[0004] The disadvantage of this heating method in the prior art is that the heating is uneven from the outside to the inside; in addition, the use of the prior art requires multiple additional heat sheets to be attached to the outer periphery of the battery, and the heating sheets are electrically connected in parallel to bring more energy to the production assembly. some trouble

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