RELAY HOLDING CIRCUIT AND BATTERY MANAGEMENT SYSTEM

The embodiments of the present disclosure disclose a relay holding circuit and a battery management system. the relay holding circuit may include: a high-voltage isolated power source, a power source driving module, and a microprocessor of a battery management system; wherein the high-voltage isolated power source may be respectively connected to two electrodes of a battery pack, an output terminal of the power source driving module, the microprocessor, and a first terminal of a first switching device; an input terminal of the power source driving module may be connected to the microprocessor; the microprocessor may be further connected to a primary battery, the microprocessor may output a low-level signal to the power source driving module when the primary battery supplies power abnormally, and the power source driving module may convert high-voltage power output by the battery pack into low-voltage power in response to the low-level signal, such that the coil of the relay may remain a conducting state during a period that the primary battery supplies power abnormally. By adopting the technical solution in the embodiments of the present disclosure, it is able to supply power to the battery management system during a period that the lead-acid battery supplies power abnormally.