Jump Start Vehicle

[Silver]

Hello . 
Electron flow from good
battery negativ black wire
to metal frame of dead car ?

Wouldnt U want electrons to
go into dead battery post ?

Also the good battery or 
alternator may die after the
boost or jump ?

thanks

 

[Optimistic Paranoid]

The positive connections should always be battery to battery.

The negative connections need not be, since a good ground flows directly into the ground post anyway.

The positive connections are always made first.

The reason they don't recommend negative to negative on the battery posts is because when the fourth and final connection is made, there is almost always a spark, and if that spark is too close to a battery, it can cause an explosion of any hydrogen gas that may have built up in the battery. 

It is possible to damage the alternator or charging circuit of a running car if you screw up and cross connect the jumper cables, positive to negative.  For this reason, they recommend that the car doing the jumping shouldn't be running during the process.

Now having said all that, I've jumped numerous cars over the years with my car running, and never had a problem.  I always insisted on doing the hook up myself, and never let the driver I was helping do the hook up.  I also used to go directly to the negative posts, again without a problem.  I stopped doing THAT when I finally understood the danger of a battery explosion.  And also because it became a lot harder to make good connections directly to those damned side terminal batteries.

Regards
John  

PS:  If you HAVE a side terminal battery in your vehicle, there are adapters that can be fitted to them to make it easier to jump them.

 

[Silver]

Yeah, its scary when the battery explodes acid on your face.

Or a terminal gets welded to the frame during a short circuit.

I've jump started half a dozen cars & witness quite a few more but things can go wrong & a fire could start.
That's where having roadside assistance pays for itself.

Do the electrons go from the good battery via positive cable to the dead battery ?

 

[Optimistic Paranoid]

Well, it was Ben Franklin who came up with the names positive and negative.  He assumed that electricity flowed from positive to negative.  It turns out that this is one of the few times old Ben got it wrong.  Electrons are negatively charged, and flow from negative to positive.

As  practical matter, whenever you have a complete circuit, electricity flows from the higher voltage to the lower, voltage being electrical pressure.

So the electrons are actually flowing from your negative post, through the battery you are jumping, and back to your positive post.

Regards
John

 

[ccbreder]

Some point to electrons not moving at all, the holes the electrons fit are what move.