Car batteries have an uncanny ability to die at the most inconvenient times. If it's pouring down rain on a cold night when you're on your way to an important event, the chances of your car battery going kaput hover near the 100 percent mark. This is why modern humans invented roadside assistance.

Tow truck drivers needn't read this article, having replaced scores of batteries in the cars of stranded motorists. If you have a car in your driveway with a battery that could stand to be replaced, follow the steps outlined here. You'll be up and running in no time at all, as it can be an easy automotive repair.

First, though, it's a good idea to see if your battery needs to be replaced or if it simply could use a good cleaning. Sulfate, created over time by the battery's discharge of lead, can build up on the terminals as a cakey white substance that prevents the battery from recharging during use. You can get rid of this sulfate with a simple solution of baking soda and water [source: Castrol USA]. Be sure the car is off by removing the keys from the ignition and brush the solution onto the sulfate to loosen the deposit. After the terminals are clean, try the ignition. If the car starts up, it should be able to recharge itself and you may not need a replacement after all.

If your battery is fully dead, consider having a professional do the job for you. Batteries can be heavy: The average car battery contains more than 24 pounds (10.8 kilograms) of lead, not including the rest of the components [source: Waste Age]. Most auto parts stores offer free battery installation when you purchase a new one from them.

At this point, you've decided your battery must be replaced and that you're going to handle it yourself. Good for you. Read on to the next page to find out what tools you'll need to do the job correctly.