How To Jump Start A Car

Recently I came across that some people out there using a wrong method to jump start a dead battery. Here I would like to teach you step by ...

Recently I came across that some people out there using a wrong method to jump start a dead battery. Here I would like to teach you step by step everything you need to know to jump start a car with a dead battery. I will also show you photos of the correct jumper cable setup, how to jump start a car battery, and give you dead battery troubleshooting tips and battery & alternator buying tips. Print this page & keep it in your trunk with the jumper cables if possible.

The 3 biggest causes of dead car batteries are leaving your lights on, not maintaining your battery properly with the correct water levels (for older maintenance batteries), and breakdown of the diode bridge or voltage regulator in your alternator. Of course some people get a bad starter, but the odds of that are low compared to the other causes dead car batteries.

How We Connect The Jump Start Cable

STEP 1: Connect one end of the Positive(+) cable to the Positive(+) post of the dead battery.

STEP 2: Connect the other end of the Positive(+) cable to the Positive(+) post of the good battery.

STEP 3: Connect one end of the Negative(-) cable to the Negative(-) post of the good battery.

STEP 4: Connect the other end of the Negative(-) cable to a good solid SHINY, NON PAINTED metal part of the engine on the dead car. Usually a giant shiny nut on the engine block will do. A painted, dirty, or oily nut will not work. You usually want to avoid placing the Negative(-) cable directly on the dead battery to minimize the chance for explosions. You should only use the ground post on the dead battery as a last resort. On this step you'll get a normal spark as you connect the ground and complete the circuit.

IMPORTANT: A Few Precautions Before We Start

The first thing you need to do is to line both cars up so the batteries are as close as can be. Make sure the cars are in park, and both cars are turned off, and not touching each other before you connect the cables. Make sure all headlights, blinkers, car radios and A/C's are off, radar detectors are unplugged, cell phones unplugged, everything off. Unplug all accessories from cigarette lighters and other power sockets from both cars. Jump starting a battery can crank 300+ volts through your system and the transients can destroy equipment. These voltage spikes are caused by inrush current, into the inductance in your electrical system.

Familiarize yourself with the Positive (+) and Negative (-) terminals of both car batteries so you know exactly which one is which. All batteries are clearly marked so if you can't find it, it's probably under 1/8" of caked on corrosion around the terminals. Wipe off any battery acid that may have leaked.

If the battery is cracked and liquid is leaking out, DO NOT go further! Bite the bullet and go buy another battery and swap it out. If you try to jump start a battery with a crack in it, it will explode, and battery acid will dissolve your eyes (on the positive side though, it does get the red out). It makes no sense to jump a cracked battery, it will die in a few minutes.

Try to clean off any corrosion around the dead battery terminals, and if you have tools, loosen the wires from the terminals, clean them off, then retighten the wires to the shiny posts. Corroded posts prevent the power from getting through the cables and into your battery to revive it. If you have a file handy, try to file the metal battery posts until they are nice and shiny. In a pinch use pliers to clamp down and scrape off corrosion too as the metal is somewhat soft.

Usually the positive battery cable is red or orange, and usually the Negative (-) or ground cable is black, but always check for yourself to be sure.