Safely Jump-Start Your Vehicle
February 7, 2023
Most of us have experienced a dead battery in our vehicles. Getting a traditional lead-acid battery to charge enough to start your vehicle is not complicated, though it does come with hazards. Knowing how to safely jump-start your vehicle can prevent damage to you, your battery and your vehicle’s components.
Before you get started
First, take a few safety precautions:
As with any electrical equipment, turn off all electrical components before proceeding with a charge. If you connect jumper cables with the battery under load, you could generate sparks, which can lead to an explosion or fire.
Keep a pair of goggles in your trunk for emergencies. Eye injuries can occur from acid spills or battery fragments.
Refrain from smoking. The hydrogen gas generated during a charge is highly flammable. Traveling vapors could easily ignite around a burning cigarette. Even if you aren’t smoking, there is still a risk of cables sparking and causing a fire. If you have a vehicle fire extinguisher, keep it within reach.
Check your battery fluid levels. If necessary, top off the dead cells with water (not acid) prior to charging. Use 8- or 10-gauge cables and ensure both batteries are the same voltage.
Safely connect your jumper cables
Follow these steps to safely connect your jumper cables. The process works best with two people.
- Make sure the vehicle being used to charge yours is running. Connect the first positive (red) clamp to the positive (+) terminal/post of the good battery (the one being used to charge the dead battery).
- Connect the other positive (red) clamp with the dead battery’s positive (+) terminal/post.
- Connect the negative (black) clamp that pairs with the first red clamp on the good battery to the negative (-) terminal/post of the good battery.
- Connect the remaining negative (black) clamp that pairs with the red clamp attached to the dead battery to an exposed metal part or frame on the dead battery’s vehicle. Do not clamp the cable to the battery terminal/post. Doing so can create a spark.
- While attaching the cables, do not allow the red clamps to touch each other. That may cause the good battery to drain, creating two dead batteries.
- Have the other person rev the idle on the good vehicle while you attempt to start the dead vehicle.
- Once the dead vehicle starts, remove the cables in reverse order: the black clamp on the dead battery’s vehicle, then the black clamp on the good vehicle’s battery terminal, then the red clamp from the jumped vehicle, and then the red clamp from the good vehicle.
You can also purchase a booster pack powered by a rechargeable battery. With a booster pack, one pair of cable clamps attach to the dead battery and vehicle frame. This setup requires only one vehicle — yours!
Whether you’re jump-starting your car the traditional way or using a booster pack, taking a few safety precautions can help keep you safe and protect your vehicle.