Battery polarity reversal
Inadequate connections
Mechanical shock or deformation
Contact with liquid or condensation oxidation
Inappropriate environmental conditions (dust, corrosive vapor, humidity, high temperature, biological infestation, etc.)
Breakage or damage caused by lightning
Damages to connection terminals and screws due to insufficient tightening
Electronical breakage (excluding lightning-related incidents) determined by the state of internal control diode and inputs/output X and Y capacitors for warranty assessment.