Jumpstart damage.

I would like some information or opinions on the actual risk of electrical damage (voltage spikes etc) caused by using a modern car to jumpstart a dead one.

I have come across many people who refuse to use their cars to give a jumpstart, claiming fear of electrical system damage. These people have never actually experienced such damage; they are simply following the advice of others. Are their fears justified?

Oddly enough, these same people are grateful to receive a jumpstart, when their cars are dead. Their fear of damage disappears when they are the ones who are stranded. :disappoin

I have jumpstarted seemingly hundreds of vehicles with no damage at all.
Every time, though, I make sure the running vehicle has headlights switched on to absorb any voltage spike.
Also, when I have used someone else's newer car to jump a dead one, I make sure the engine is not running during the jump. I figure there can be no harmful spike if the ignition is off.

Your thoughts?

What I prefer to do is keep a charged portable jumpstart pack in all my cars. If someone needs a jump, I connect the pack up and use that. No need to get the cars close to one another, no need to worry about spikes, not concern to my property if someone hooks a cable up wrong, etc.

The car battery should do a pretty decent job of filtering out most noise or relatively large spikes. I'm not sure where an overwhelming spike would come from. The times that I have jumpstarted cars with a car, I've made sure the donor car was running and prior to the jumpstart attempt, as well as while trying to start the dead car, I would race the donor engine to about 2k rpms and hold it there so the alternator is helping out more. When doing this, the engine of the donor car bogs very little during the start attempt.

In my opinion, the concern for a voltage spike is not as big as the concern of a potential large short circuit in the dead car or the potential for a frozen battery to destruct when trying to charge it by jumpstarting. I've never personally witnessed either of those.

I must admit, I made a lot of new friends in college with the portable jumpstart pack.

-Rod

You also have to consider the risk of explosion from any outgassing from the battery. I met an individual a few years back who being a Good Samaritian attempted to give a jumpstart to a stranded motorist, and the battery exploded in his face. His face was disfigured from the acid and needed a lot of plastic surgery to repair the areas affected.
I use a jump pack myself, and have noticed that all the AAA tow truck drivers and other non-AAA tow truck drivers in my area have also adopted the use of a jumppack in place of the traditional jumpstart.