Question for the electrical engineers and gurus
 

Which Batt if any in a two batt system like on a diesel pickup (two batt in parallel )
Should be used to jump a single batt vehicle?
I say it does not matter.
Others say it does.
I can not find a technical write up anywhere.
I have jumped many vehicles and never payed any atn, to which i hooked up to.
Your thoughts?

Doesn't matter.......either one will provide 12 volts.

I understand that.

Doesn't make a difference.

.

The one that's closer will provide .000000000000000001% better performance.

I guess the stupid in the argument is that the alt wire is on one side, not both.
I think the answer is there is no correct answer, which is what i thought.

You could totally calculate the voltage/current drop in the length of cable that is farther away from the alternator, if you knew the properties of the cable used in the construction of the vehicle. :) I just did a quick mental calculation based on the knowledge I acquired from my Bachelors of Music.

It cant be worth the effort....LOL

If they are truly in parallel, there should be no difference. They are both are used to turn the starter and should be balanced, or one will die before the other. The same is true for charging.

Besides, with a diesel truck, the alternator is usually an extra heavy duty. I doubt you will be pulling current from anything except the alternator. Most battery cables should be used to CHARGE a battery, not try to start a car.

Doesn't matter...the battery that is further away from jump cables will provide slightly less amperage due to miniscule voltage drop across the cables that is connecting it to another battery...that's all.

Doesn't matter.

Voltage= Amperage x Resistance: https://en.wikipedia.org/wiki/Ohm%27s_law

Batteries in parallel stay 12V but the amps available double(assuming both are same).
If one drops it gets refilled by the other.
Considering that most of the resistance is in the discharged battery and it has a much smaller mass and electrical potential than the two in the truck, any resistance in the cables/connection should be negligible.
The limitations are in how fast the dead battery will accept new electrons.

Resistance does play a larger role at higher voltages, but this is only 12V.

Doesn't matter, but I'm real curious as to the reasons given by those who say it does.

What reasons do they give so we can laugh at them?

Some stupid idea about the alternator charge wire is going to one battery or the other.
Its a elementary thought as thats not how the systems charge anyway (unless your name is Lucus ) LOL

This should help:

http://forums.pelicanparts.com/uploa...1426089479.jpg