Car battery
What it is and why it matters
The 12-volt battery starts the engine and powers the electronics. Its capacity fades with age and heat until one cold morning it can’t turn the engine over. Because the failure is sudden, it pays to replace on age rather than wait for the no-start.
DIY vs. shop
$100–250 for the battery, 15–30 min, one of the easiest jobs on the car.
Similar part cost plus modest labor; many parts stores test and install free.
Costs are rough US ballparks and vary by vehicle, parts, and region.
Good to know
A typical battery lasts about 48 months (~4 years). After year three, have it load-tested annually — slow cranking, dim lights, or a dashboard battery light mean it’s time. Log the install date so you always know the battery’s real age.
Log it in MyGlovebox.
Snap the receipt (or record your own work) and it lands on your car’s timeline — with a reminder set for next time.