Engine cranks slowly or not at all
Clicking sound when turning the key
Dashboard lights are dim or flicker
Headlights are weak or fade quickly
Electrical accessories work poorly
Battery warning light is on
Battery case is swollen, cracked, or leaking
Corrosion is built up on the terminals
Battery is more than 3 to 5 years old
Car needs frequent jump-starts
Battery voltage is low on a multimeter
Battery fails a load test
Vehicle starts after a jump but dies soon after
Smell of rotten eggs near the battery