In rec.autos.tech, on Sun, 18 Jun 2017 16:34:34 -0700 (PDT), dsi1
> wrote:

>On Thursday, May 14, 2009 at 3:21:30 PM UTC-10, Hachiroku ???? wrote:
>> On Thu, 14 May 2009 23:36:07 +0000, Tegger wrote:
>>
>> > "Ulysses" > wrote in
>> > :
>> >
>> >>
>> >> "Don Stauffer" > wrote in message
>> >> ...
>> >>> jim evans wrote:
>> >>> > For years I've heard the advice to coat battery posts & terminals
>> >>> > with Vaseline to prevent corrosion. I've never done it because
>> >>> > it seems like the grease would act like an insulator and impede
>> >>> > electrical conduction between the posts and terminals.
>> >>> >
>> >>> > Do others who use it have any problems with conduction? If not,
>> >>> > why do you think that's so?

You need grease that conducts electricity. I forget the 3-syllable
word, but they sell little envelopes of it at autoparts store, just for
electrical things.

I've never used anything on my battery posts and in 55 years I've never
had corrosion. But I do use the red and green felt washers sold for
batteries, they are great and afaict last for years.

But once I had a switch or something filled with grease at the factory,
and if I rebuilt it, I replaced the grease with the stuff above.
>> >>>
>> >>>
>> >>> While the vasoline MAY be squeezed out from within the connection,
>> >>> the normal way to apply it is AFTER the connection is made. That is,
>> >>> with the cable connected to the battery post, paint the vasoline
>> >>> around the connector, on all exposed lead and other metal.

I would think vaseline would be wet and runny when the weather is hot.
>> >>
>> >> While I basically agree with this statement I always put it on before
>> >> connecting the cable
>> >
>> > I do this too. But then my cable connectors are aluminum, and have little
>> > barbs that bite into the battery post when they're tightened. Old-style
>> > lead clamps that are smooth on the inside may not provide enough "bite" to
>> > get through the grease film.
>> >
>> > However, since the posts are tapered, it's possible the bottom of the lead
>> > clamp is wedged on firmly enough to make proper contact in spite of the
>> > grease.
>>
>> >> because I have lots of problems with corrosion
>> >
>> > Then your post-to-case seal is broken. This is usually due to some sort of
>> > mishandling or overtightening.
>>
>> Like beating on it to make the car start?
>>
>> > Treat your battery with kindness and care, and ye shalt remain corrosion-
>> > free, forevermore.
>
>Beating on a battery terminal can allow a car to start - if the problem is a poor terminal connection. I used to start my Ford Taurus by opening up the hood and whacking on the box that housed the relays. They were all in a single sealed box that didn't allow access to the relays. It one of the greatest idea Ford ever came up with! The fuel pump relay was kind of flakey. Sometimes you just got to kick car ass.

I had a '65 pontiac, almost new, and every time the lights were left on,
the car wouldn't start until I reached under and pulled the cable at the
starter motor a few degrees around the stud it was attached to. I got a
buzzer that buzzed if the lights were left on and that stopped that
problem.

And I had a convetible top motor for which I had to open the trunk and
whack the motor with a wrench. As time went on it sometimes took 3 or
more whacks, but once it started runnign it always ran fine until the
top was up or down as the case may be. This went on for almost 2 years
until I had to replace the brushes in the motor, but the brushes I
bought, though the right size, had copper braid connectors that were
much smaller than the original (they were meant for a smaller motor) so
I wadded up a little piece of aluminum foil and put it between the brush
housing and the spring behind each brush. That worked fine for years.