Parts King Parts King

How To Jump Start A Vehicle Battery

Revive a dead battery quickly and easily with these simple DIY instructions. 

Here’s What You’ll Need:   

  • Jumper Cables
  • Hand & Eye Protection
  • A Functioning Car Battery (to provide the boost)

Words of Wisdom From The King: 

  • Every vehicle is different. Always follow the owner’s manual when it comes to maintenance and repairs.
  • Safety should be your number one priority. Don’t smoke, drink alcoholic beverages, or wear a necktie while working on the car. Watch out for hot objects, sharp instruments, hazardous materials and other potential safety hazards in and around your workspace.
  • Don’t work with a Philips when the job calls for a flat. Substituting tools can compromise your safety or your vehicle’s performance.
  • Finally, when the fun turns to frustration, or if the job requires specialized knowledge beyond your capabilities, please do not attempt it yourself. Talk to a professional mechanic or installer.

Before You Begin:

The top three reasons for a dead battery:  

  1. Leaving your lights on
  2. Not maintaining your battery properly with the correct water levels (for older maintenance batteries)
  3. Breakdown of the diode bridge or voltage regulator in your alternator

Of course, a dead battery may also be due to a faulty starter, but this is far less likely. 


  • Line both cars up so the batteries are as close as can be. Make sure the cars are in park and that 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, and cell phones are unplugged. 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 inductances 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.

IMPORTANT: DO NOT attempt to jump start a battery if it is cracked and/or leaking. Batteries with cracks can explode. You must purchase a new battery. 

Steps to Successfully Start Your Battery 

  1. Try to clean off any corrosion around the dead battery terminals. 
  2. If you have tools, loosen the wires from the terminals, clean them off, and then re-tighten the wires to the shiny posts. Corroded posts prevent the power from getting through the cables and into your battery to revive it. 
  3. 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.
  4. Connect the battery cables to the corresponding posts. The Positive (+) battery cable is typically red or orange, and the Negative (-) battery or ground cable is usually black, but always check to be sure.
  5. Leave the cables on for five minutes to start. Keep in mind, batteries may take up to 30 minutes to charge in colder temperatures.