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error Schumacher
Error Code F04
Connections to the battery are reversed.
? What Causes This
Incorrect orientation of positive and negative terminals when making connections.
✓ How to Fix It
Unplug charger from outlet. Correct polarity and reconnect properly before attempting charge again.
Source: page 10 of the official manual
From the manual
This error code appears in:
Schumacher Sc1308