What is your jump starting proceedure?

So, yesterday my daughter calls me wanting to know where the jumper cables are, her boyfriend's car has a dead battery. She grabs my good set (made with #4 welding cable) and heads to his house. Then she calls and asks how to hook the cables up, she has seen me do this before but has not done it herself. She has already positioned the vehicles and identified which battery terminals are which.

I tell her the basic procedure keep cables clamps from touching, hook up the negative to one car then the other, then the positive to one car and then the other. I 'know' the recommended procedure is/was to connect the negative clamp to the block, but honestly you can't reach the block on some cars now, besides which you are only bypassing a few feet of the ground cable on the car from battery to block.

So, her boyfriend asks me last night why I said to hook up the ground first. He read his owners manual (he is an engineering student and not afraid to read manuals ) and it said to connect the positive clamps first. I told him it really does not matter, electrically, and that I always have done the negative first, I suppose my Dad taught me that. I could not think of a logical reason for preferring one over the other.

When disconnecting battery cables it is preferred to do the negative first as after it is disconnected if you should happen to slip with your wrench and touch the positive terminal of the battery to the car's frame you won't get that exciting spark and brown streak in your shorts. When jump starting though I can think of no such logic that would dictate going positive or negative first unless you were to want to hook the negative clamp to the dead vehicle's block.

So, perhaps this is a long winded discussion about nothing but I'm wondering if you all were taught any specific reason for which cable to connect first when jump starting.

I've always heard the same thing about the 'correct procedure', but never noticed any difference in practice. I usually do positive first, but I can't say I have a specific reason why. :silly:

Congrats to your daughter for getting the job done! Most drivers anymore just call AAA or a tow truck. :lol: Honestly, I've been using jumper packs for so long, I can't remember the last time I used actual jumper cables...

Completing the circuit should be at the block to keep Sparks away from the battery. That's it. I've seen batteries explode from sparks.

EricGoodrich wrote: Completing the circuit should be at the block to keep Sparks away from the battery. That's it. I've seen batteries explode from sparks.

Yes sir, seen a few explode myself.

I have 2 batteries in my Cat loader at the junkyard making 24v.
If you can use a meter and your head, you can jump start it with one 12v battery. (For some reason one battery goes flat first).

Thanks for your replies guys. I have only ever seen a battery on the verge of exploding once and that was from severe overcharging. It was on an old Ford truck and the voltage regulator was putting out 18V! I bought some wood from the guy and he was talking about having issues with it starting, I stood near the hood and could hear the battery hissing. Once I popped open the hood and saw the battery case had expanded I had him shut it off and we waited until the battery was done venting. I had him start it up and then disconnected the battery cable so he could drive into town and get it fixed.

A battery will vent hydrogen anytime it is rapidly charged of discharged. So, if your cranking and cranking until the battery goes dead the battery will be venting like crazy. Best to let it sit a while when that happens as no matter how you are hooking the cables up the battery is still hot and venting from being over used.

My only issue with hooking the ground clamp to the engine block is that in many newer cars it can be almost impossible to access due to all the plastic 'beautification' panels.