A few questions about using jumper cables

[pharmvet]

After being shown several years ago how a really good set of jumper cables was far superior to a cheap small set, I purchased 3 sets, made from very heavy leads, by a local electrical shop . I keep a set in each vehicle I have. They have been very useful on many occasions. However, I have realized that there are a few things I need to know and have in order to get full and proper use of them.

1) All my vehicles have side terminal battery posts. As you probably know, it is almost impossible to get the clamps of the jumper cables to stay attached to the small head of side terminal bolts. Are there replacement side bolts that will allow solid attachment of the jumper cable jaws?

2) I have always attached both ends of the jumper cables to the respective pos. and neg. terminals of the "jumper car" and the "to be jumped" car. In doing some reading, It seems that the proper way is to attach the net jumper cable clamp on the "to be jumped car" to a "ground" piece of metal on the frame or motor, rather than the neg battery terminal. Why is this?

 

[Midniteoyl]

Second first - Its because you can get a spark which could cause any hydrogen gas released by the battery to explode..


As to the bolts - Yes there is. An autoparts store or farm&fleet should have them. They look like this:





If those arent 'long' enough, they have 'extenders'.. :

 

[wyeguy]

Don't know about #1, sorry.

#2 is because when you make the last connection, a spark occurs, which can ignite gas coming from the battery and the battery can explode. This happened to my son in law, a good mechanic who "got away" with doing it the way you do it, until one time he didn't. Battery blew up and he got a face full of acid. If the spark occurs at the frame away from the battery, there's a much lesser chance of an explosion. But then ya gotta keep it away from the fan, belts, etc. I connect to the frame AND wear safety glasses.

 

[pharmvet]

Thanks for the answers everyone.

Regarding attaching the neg. clamp to a ground rather than the battery terminal, Could you reverse this and ground the jumper cable on the car used to do the jumping, or does the good battery have to utilize both of its terminals?

 

[Midniteoyl]

You could, but its not necessary as you connect to the jumping car first. Since theres no power draw, theres no spark.

 

[5picker]

# 2 has been answered.

Adapters for the terminals are one solution for question # 1 but since the OP mentioned H/D leads manufactured by an electrical shop and didn't specify the clamp type, my guess is they have what are referred to as 'parrot' style clamps. Great for top posts but not much account for side posts. If they are in fact parrot style, maybe the OP should consider upgrading to this style clamp designed for side posts. 14-600 by Goodall.

 

[reb]

Thanks for the answers everyone.

Regarding attaching the neg. clamp to a ground rather than the battery terminal, Could you reverse this and ground the jumper cable on the car used to do the jumping, or does the good battery have to utilize both of its terminals?

Grounding the jumper cable on the jumping car and connecting to the terminals on the dead battery would increase the resistance in the path to the starter. That would drop the voltage to the starter more than doing it the other way.

 

[Soundguy]

it's already a bad day if you have the cables out.

I remember when cars had metal bumpers.. and in an emergency a coat hanger would jump a car after you puleld bumnper to bumper.. then let it charge about 10-15m prior to get SOME charge in her. then hit the starter on the car and watch all the varnish burn off the coat hanger instantly.

 

[reb]

You could, but its not necessary as you connect to the jumping car first. Since theres no power draw, theres no spark.

That could be a dangerous assumption. Connecting a charged battery across a discharged battery will result in an instantaneous power draw, hence the likelihood of a spark.

 

[Midniteoyl]

?? Connect charged batt, then discharged batt...

The question was 'do you have to place the neg on a bare metal part of the jumping vehicle also, or on the neg post of the batt?' I said you do not have to use a metal part of the jumping vehicle as there is no connection to the jumped vehicle so no completed circuit.

 

[reb]

I don't completely understand. I read your first response as saying there was no danger of a spark when connecting the ground connection. If the cables are both connected to the jumped vehicle's battery, and the positive lead is connected to the positive post of the battery, there is very likely going to be a spark when the negative lead is connected to the frame of the jumping vehicle. That is connecting the charged battery across the discharged battery.

I apologize for the misunderstanding.

 

[bcp]

The spark will occur when the last of the four connections is made, no matter what order you connect them.

The preferred location for the spark is on the frame of the vehicle with a dead battery.

Bruce

Found a diagram, from:
http://www.247usedparts.com/articles/jumper-cables.shtml

 

[reb]

The spark will occur when the last of the four connections is made, no matter what order you connect them....

Bruce, you got it right; that is what I was trying to say.

A spark will occur also when the first connection is broken, which is why the recommended procedure is to disconnect the ground on the jumped vehicle first.

 

[8n Bruce]

Check your owners manual , some vehicles come with a remote positive post under the hood ,more for an isolation of the stater from the rest of the electrical system ,but can be utilized for boosting purposes. But check the manual first.

 

[sam5570]

it's already a bad day if you have the cables out.

I remember when cars had metal bumpers.. and in an emergency a coat hanger would jump a car after you puleld bumnper to bumper.. then let it charge about 10-15m prior to get SOME charge in her. then hit the starter on the car and watch all the varnish burn off the coat hanger instantly.

you gonna tell your age if you not careful you left out vice grips to hold the coat hanger on. they turn a little black to.

 

[sandman2234]

Back in the 70's I carried a single piece of welding lead, with nothing on either end. I just cut back the insulation an inch or so and mushroomed the end. Anytime I needed to jump somebody, just bumper to bumper and one person holding an end to the positive terminal, if one couldn't reach both batteries and you had plenty of juice to start. A piece of welding lead carries just a tad bit more current than a metal clothes hanger, and a heck of a lot more than todays plastic clothes hangers. Course, with todays plastic bumpers and the price of welding leads....
David from jax

 

[Soundguy]

you gonna tell your age if you not careful you left out vice grips to hold the coat hanger on. they turn a little black to.

we was poor. had no vicegrips. we pulled the bat cables off and put the hangers under them. half the time it melted one end of the hange off anyway.. so only had to bend one back and forth to break it off, and then go!

 

[PILOON]

you gonna tell your age if you not careful you left out vice grips to hold the coat hanger on. they turn a little black to.

Hey, I've done it with 2 vie grips! (never have enough VG's)

Since I only have GM products and hate side terminals I generally always clamp neg to engine parts thus only have 2 iffy connections to worry about.

 

[Midniteoyl]

I don't completely understand. I read your first response as saying there was no danger of a spark when connecting the ground connection. If the cables are both connected to the jumped vehicle's battery, and the positive lead is connected to the positive post of the battery, there is very likely going to be a spark when the negative lead is connected to the frame of the jumping vehicle. That is connecting the charged battery across the discharged battery.

I apologize for the misunderstanding.

I do think you're saying the same thing as I..

IF you connect the jumping car LAST then connect the neg to the frame... But, you are suppose to connect the jumped car last, so, if you do it the way you're suppose to, there is no need to connect to the jumping car's frame.

 

[weedpharma]

Another thing to be careful of is damage to the ECU. It is possible (though not guaranteed) that the ECU can be damaged because of incorrect jump starting causing a voltage spike.

If you have the donor vehicle running when you try to start the dead vehicle, the donor alternator regulator will see a low voltage and feed high current into the alternator to try to get the voltage back to what is required. When the dead vehicle starts, the battery voltage goes up but the regulator takes a short time to compensate so is still flat out. This causes a spike that may damage the ECU.

I connect the donor to the dead vehicle and charge the dead battery for a couple of minutes. I then turn off the donor and start the dead vehicle. This way the donor battery is simply in parallel and no spike occurs. The donor is good for a few attempts without excess drain to the donor battery.

Weedpharma