The first thing you want to remember when jump-starting a car is that
a slight possibility of explosion does exist. This is because hydrogen
gas--which forms as a battery discharges and loses its fluid--is flammable,
and a spark from the battery cables could, theoretically, set it off.
We emphasize slight because the gas would have to be fairly
dense around the battery for this to happen. This is unlikely unless the
battery has been sitting for a long time and little or no air circulation
has occurred in the area, but it is possible.
That said, I should add that in the last 15 years I have performed at
least 50 "jumps" on various automobiles (you see, I used to own a lot
of Chrysler muscle cars) and have never had a problem. One of the keys
to avoiding the big bang is to hook up your jumper cables in the proper
order. Follow along and we'll show you how.
Step One
Park the booster vehicle close to the one that needs to be jumped,
but not so close that the vehicles are touching in any way. You'll want
to use a good set of jumper cables with thick wire and clean clamps. As
you are hooking up the jumper cables, make sure they don't dangle into either
engine compartment where they could get caught on moving parts (belts, fan,
etc.). Turn off the ignition of both vehicles, set the parking brakes, and
make sure that they are in either "Park" or "Neutral" depending on whether
the vehicles have an automatic or manual transmission. Also, turn off all
accessories like lights, radio and, if the vehicles are in a safe area,
the hazard flashers.
Step Two
Begin the process by clamping one of the positive jumper cable ends
(red) to the positive battery terminal (labeled with a "+" on the battery)
of the dead vehicle. Be sure the connection is strong with the clamp securely
"biting" onto the battery terminal.
Step Three
Connect the other end of the positive cable (red) to the positive battery
terminal on the booster vehicle (again, confirm that a "+" is next to the
battery terminal). If the terminals are corroded on either vehicle, you
may have to scrape them with an abrasive such as steel wool to achieve a
solid connection.
Step Four
Connect the negative cable end (black) to the negative battery terminal
on the booster car (marked with a "-"). Finally, attach the other end of
the negative cable to an unpainted metal surface on the engine of the dead
car. Find an unpainted bolt or bracket that is as far from the dead battery
as possible. This will provide a solid ground while further reducing the
possibility of igniting any hydrogen gas.
Step Five
Make a final check to confirm that the jumper cables are not near
any moving engine parts, and start the booster car. Let it idle for several
minutes, depending on the state of the dead battery. If the dead battery
is new and was drained by the lights being left on an extended period
of time, it will probably start immediately. If it is an old battery or
it has sat for a long time (more than a month) it will probably take awhile
to charge it sufficently.
Step Six
Start the dead vehicle and let the two vehicles idle for a few minutes.
If the dead vehicle refuses to start, don't keep trying or you might damage
the starter. If there is the possibility of additional problems, like
a lack of fuel, don't continue trying to start the dead vehicle until
the other problem(s) are solved.
Step Seven
Once the dead vehicle is started and running smoothly, disconnect the
jumper cables in the reverse order that they were connected. As you disconnect
them, be careful not to let the dangling cables fall into the engine compartments
or touch each other.
Step Eight
Drive the revived car to somewhere safe and secure before shutting
off the engine. Depending on the battery's condition, it might need to
be jumped the next time it is started. To properly charge the battery,
attach it to a certified battery charger and leave it connected for at
least 12 hours. You can also take it to an automotive repair shop for
complete charging. Driving the car for an extended period can also charge
the battery, but this should be done only if the other two options aren't
available. A vehicle's alternator is primarily designed to maintain a
battery, not charge it from a complete drain.
