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Mechanic is connecting a booster-cable to the battery in order to jump-start a car credit: istockphoto
Mechanic is connecting a booster-cable to the battery in order to jump-start a car credit: istockphoto

Ask Joanne

The dangers of boosting a car battery Add to ...

Last week, in a mall parking lot, another driver asked me for a boost. Neither of us had cables so I couldn’t help, but it got me wondering whether this is even a good idea? Are there any dangers to boosting a vehicle? – Leah in Burnaby, B.C.

With the multitude of systems in modern vehicles, boosting a battery can be riskier than it was in the days before cars contained complex computerized systems.

“It sounds simple, and I’d say most of the time it is, but with modern technology it’s not as simple as it used to be. If you make a mistake boosting a battery it could have pretty serious consequences, particularly to automobile computers and charging systems,” says Ken Cousin, associate vice-president of BCAA Road Assist, which receives 200,000 annual “battery calls.”

“Computers are expensive, they don’t like to be boosted backward, and they don’t like something called ‘voltage spikes’,” Cousins says. “Automobiles are really sensitive to peaks in electricity and that can happen when a car is boosted.”

If you decide to give someone a jump, or the time comes when you require one, there are guidelines to help ensure a safe boost.

Batteries emit hydrogen gas and there is a chance that in the presence of a spark or flame they will ignite. “They can literally explode. The acid inside is highly corrosive for your eyes, skin, and clothes. That’s why, when technicians boost vehicles, you’ll see them wearing safety goggles. If it does end up exploding, it tends to shoot straight in the air and there’s acid all over the place. I had one blow up when I was boosting once; it happened awful quickly and it was sort of like standing beside a shotgun,” says Cousin.

After making sure you’re protected with goggles, gloves and overalls, check your vehicle owner’s manual for any specific instructions from the manufacturer on boosting procedure. The manual may also be useful in helping locate the battery. Sometimes it’s in the trunk, or buried beneath other components with only a charging post visible.

To begin: the vehicles must not touch, while being close enough for the cables to reach each battery. The engine in both vehicles, and any accessories, should be turned off. Attach the positive (typically red) cable to the positive post on the dead battery, and then attach the remaining positive clamp to the corresponding post on the working battery.

Next, attach the negative clamp to the negative post on the working vehicle.

Lastly, do not attach the negative cable to the negative post on the disabled battery. Instead, it should be clamped to another metal surface in the engine compartment. This ensures a good ground, and lessens the potential for explosion and damage to the electrical system.

Start the good vehicle and let it run for a few minutes. Now start the dead vehicle. Unhook the cables in reverse to the order which they were attached.

It’s estimated that 35 per cent of the 30 million annual calls for assistance received by the AAA federation from members are battery-related. The odds are good that at some point all motorists will either require, or be asked, for a boost.

“My advice is if you don’t have experience boosting batteries don’t take the chance. You could cause more damage, for example if you inadvertently hook it up backward,” says Cousins. “In the old days, if something sparked or got smokey, you knew ‘Oops, something’s backward,’ but with modern vehicles by the time that happens it’s likely that much more damage has occurred. So it’s not something that we recommend to amateurs.”

If you have any doubt about performing this procedure, then leave it to professionals.

 

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