Battery diagnosis apparatus

A battery diagnosis apparatus for diagnosing a state of a battery, the battery diagnosis apparatus comprising:

• a current source configured to apply a pulse current to the battery;
• a voltage sensor configured to detect a voltage between terminals of the battery;
• and
• a control device, wherein
• the control device comprises:
• one or more processors;
• and
• one or more memories coupled to the one or more processors, and
• the one or more processors are configured to execute processing comprising:
• acquiring a voltage response obtained by applying the pulse current from the current source to the battery;
• deriving, based on the voltage response, an index indicating a comparison between an on-ATRF and an off-ATRF, the on-ATRF being an apparent transient resistance function of the battery when the pulse current is turned on, the off-ATRF being an apparent transient resistance function of the battery when the pulse current is turned off;
• and
• determining a degree of deposition of lithium in the battery, based on the derived index.