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.