Guides

In-depth, practical electrical engineering guides, each with the live calculators you need to follow along.

A 12V car battery in an engine bay with a jumper-cable clamp on the positive terminal
Battery

How Long Do Car Batteries Last?

Most car batteries last three to five years. Here is what really controls that number, how to spot a battery on its way out, and when to replace it.

Jul 5, 2026 · 19 min read