How to jump your car battery correctly
In the world of automotive emergencies, motorists need to learn certain procedures for "safety's sake." Two of the most valuable lessons, changing a tire and hooking up jumper cables are best learned before an emergency arises.
The process of boosting a battery is especially important in cold weather. Jumper cables or cables on a portable battery booster should be connected properly to avoid sparks, which can cause an explosion of the hydrogen gas emitting from a battery. Beyond this, an incorrect hook up can damage critical, and expensive, electronic components.
The procedure is simple:
First, connect the positive (+) clamp to the positive terminal of the healthy battery and the other positive clamp to the corresponding terminal of the dead battery.
Next, the negative (-), or ground, terminal on the good battery and, finally, the negative clamp to the engine block, frame or other grounded metal as far as possible from the battery. You want to avoid sparks in the vicinity of the explosive hydrogen gas that emits from the battery. Do not connect it to the ground terminal (negative). When using a portable battery booster, the process is much the same.
Connect the positive clamp of the booster cable to the positive clamp of the dead battery. Then connect the negative cable to the engine block or other grounded metal away from the battery.
The Council offers an additional suggestion: if you are buying jumper cables or a portable battery booster, buy the best quality you can afford. Look for well-insulated clamps and 8-gauge wire. (Note: the lower the wire gauge number, the heavier the gauge.) Under the heavy electrical load of boost starting, lightweight cables may not be able to deliver enough current to start some engines. In fact, they have been known to melt in the user's hand.
If your battery is three-years old or older and you haven't had it checked, it's a good preventive measure to do so, suggests the Council. A battery's power is reduced as the temperature drops. And that's when the engine's starting demands are greatest.