Battery management system having a plurality of backup communication main units, and aircraft

A method of reserving backup communication main units, wherein the method being used for selecting a backup communication main unit in a battery management system, comprises the following steps:

• S1:
• setting a battery management unit ID in the battery management system;
• S2:
• using a magnitude of the battery management unit ID as a standard for setting a priority of the backup communication main unit, wherein as the battery management unit ID decreases, the priority of the battery management unit ID increases;
• S3:
• confirming whether a current communication main unit in the battery management system has failed, and when the current communication main unit failed, selecting the battery management unit ID with a smallest position, among M battery management units, as a new communication main unit;
• and
• S4:
• allowing the new communication main unit to forward the data from N sets of power battery modules connected in parallel to a complete ALLCAN network.