When to replace battery on 2006 Toyota Highlander?

You should consider replacing the battery on your 2006 Toyota Highlander if you notice signs of weakness, such as slow engine cranking, dimming headlights, or electrical issues. Generally, car batteries last between 3 to 5 years, so if your battery is approaching this age or older, it's a good idea to have it tested or replaced. Additionally, if the battery shows corrosion or leaks, it should be replaced immediately. Regular maintenance checks can help determine the optimal time for a battery replacement.