You know that over time, parts of your car will start to fail, often due to wear. While the battery doesn't suffer the same stresses as mechanical engine parts, it, too, can die if you accidentally drain it by leaving the headlights on or the door ajar, if your alternator isn't working properly (to return charge to the battery), if terminals are corroded, or if it's simply old. It can also go kaput if you just don't turn on your car for a while... like if you're stuck at home during a quarantine, for example.
If you want to avoid a towing fee and the cost of a professional battery recharge (or worse, replacement), you may be able to get things going again with a jump start, whereby you use some charge from another vehicle to recharge your own battery. There is some risk involved, but when you know what you're doing, the process should be relatively smooth and easy. Here are the basics of jump starting a car.
Know Your Poles
The first thing you need to know is that the terminals on your battery are NOT interchangeable. One is positive and one is negative, and if you mix them up, it can fry your electrical system, so be very careful how you place jumper cables! Frequently, terminals feature a plus (+) or minus (-) symbol so you know which is which, and/or cables are red (positive) and black (negative).
Conveniently, many jumper cables also feature red and black wires or handles on the alligator clips. What if you can't find any indication of the polarity on terminals? The positive terminal is bigger than the negative terminal, so eyeball it or use a micrometer for accurate measurement and total certainty.
Connect the Cables
Once you've identified the terminals, it's time to connect your jumper cables. Robust cables are best, so choose a product that's minimum 4-6 gauge, and consider opting for longer cables (20 feet) so you don't have to position vehicles grille-to-grille to hook up.
The process of connecting the jumper cables is specific and designed to avoid sparks that could lead to a possible fire. Start with both car engines off, and once you begin, DO NOT let the jumper cables touch each other, as this could lead to sparks that burn your hands or ignite any flammable gases or liquids in immediate surroundings.
Connect the positive (red) jumper cable clip to the positive terminal on the dead battery first, making sure the clamp is securely fastened to the metal post. Don't let the black cable touch any metal. Next, attach the other end of the positive cable to the good battery in the other car. From there, you'll connect the negative (black) cable to the negative terminal on the good battery, and finally, you'll ground the other end of the negative cable on a solid, unpainted piece of metal on the car with the dead battery.
Now you're ready to transfer power. Start the car with the good battery and let it run a few minutes. Next, try to start the car with the bad battery. If it starts, leave it running a few minutes before removing jumper cables in reverse order of how you placed them. Drive your car for at least 15 minutes to fully charge the battery before turning it off. If it the engine won't start, check to make sure jumper cables are securely fastened and try again. If you can't start your engine, it's time to see a mechanic.
Replacing a dead battery can cost a pretty penny, but if you have jumper cables and access to a car with a good battery, you could solve the problem quickly and with zero expense. You just need to exercise caution to ensure a safe and successful jump.