Method and device for upgrading energy storage system

The invention discloses a method and a device for upgrading an energy storage system. The method comprises the following steps: determining a host and a slave of the energy storage system according to the number of modules of the energy storage system, and selecting a host upgrading path and a slave upgrading path according to the number of channels of a CAN bus. The host is upgraded through the host upgrading way, and the host is controlled to upgrade the slave through the slave upgrading way. Compared with the prior art, it is not needed to distinguish whether the energy storage system is a single-machine system or a multi-machine system and then upgrade the energy storage system, the method supports automatic identification and automatic selection of an upgrade path, and the upgrade efficiency is higher. And a plurality of slaves are upgraded through the host, so that the problem that the bus load rate is increased when the slaves are upgraded in batches is avoided, the upgrade failure rate is reduced, and