On Tue, 24 Feb 2015 11:58:37 -0800, John Robertson
wrote:

On 02/24/2015 10:36 AM, Fester Bestertester wrote:
There are some members of electronic forums that suggest coating automotive
battery posts with grease ("any king--axle, lithium, copper") before
attaching cable-end clamps to the posts and swear that it doesn't affect the
connection adversely.

Are they nuts? Grease between terminal elements?

What grease--if any--is best, inside or outside the terminal connection?

Thanks.


Grease can improve electrical connectivity if designed for that purpose
- check out Dow Corning #4 dialectic grease - we use it on many power
connectors and it not only reduces contact friction, and protects
against oxidation, but the connector actually is often cooler than one
without the grease added!

John :-#)#

Yes.

I wouldn't use non-conductive grease on a battery post because the
connection will not always be as tight as it should be.

They sell small envelopes of dielectric grease at the parts counter of
consumer autoparts stores, like Pep Boys, Autozone. The size of
envelopes of ketchup and on a rack next to others with
brake-pad-anti-squeak. spark-plug-anti-sieze, and a couple other things.
It costs between 1 and 2 dollars. Enough for two cars, at least.

They have the envelopes at real autoparts stores too, but not right
there on the counter.

Do some cars still come with spring loaded battery-cable ends.? They
can't be tightened any more than the spring inside makes them tight, and
they eventually get loose, regardless of grease. When they're not
tight enough, they should be cut off and replaced with an add on
cable-end, or if there's not enough slack, a whole new cable. Even on
those with bolts for tightening, I've seen the bolt or nut or the lead
that holds the bolt in place get stripped and require replacement.

If when the car is runnning or you're cranking the engine, the battery
post and the clamp surrounding it are hot to the touch, the connection
there is bad. A good connection will not be discernably hotter than
"room temperature." Backwards from the way it might seem.

With a battery cable at the battery post, after it cools enough that you
won't burn your hand, or with a leather work glove, you can very often
have success by grabbing the cable and rotating it around the post 10 or
30 degrees, and then pushing it back where it was (and pushing down at
the same time, so it might be on a little tighter) It's likely to be
loose enough to do this, because if it weren't loose, you probably
woudn't have the problem in the first place. Also buy a battery
post/terminal brush. Two brushes in one piece, for 4 dollars in
plastic, 6 in metal. You'll need to use this whether you use grease or
not, before you put on the grease. . One brush should last you for the
rest of your life.

I've never used such grease on battery posts, and I've never had a
problem there. But some people might. With a '65 Pontiac, I had
major connection problems between the positive battery cable and
everything else at the starter motor. If I left the headlights on for
two hours or more when the car wasn't running, the starter motor would
barely turn, even if the battery was jumped. I don't think such grease
was easily available in 1969. It certainly wasn't on display at the
parts counter. Maybe it would have solved the problem.

After the new car dealer where my brother bought it replaced the
starter, alternator, and regulator twice each, they said, and then
woudlnt' try fix it anymore (even though they had never fixed it)
because they said the two-year warranty had expired, my brother went to
Viet Nam and gave me the car. and when I took it to Sears for one more
battery, they found the problem for free in less than 5 minutes. What
the dealer couldn't find in 2 years. The Sears man took apart the
connection and scraped or cleaned the parts. When it happened again
(after leaving the headlights on) at first I took it apart too and
scraped the parts with a knife, but eventually I learned to reach under
the car, grab the battery cable and pull it towards me once and push it
back once. I could do this in nice clothes without even getting dirty,
except my hand a little bit. Maybe you can't do this with a compact or
small car. Eventually I came across a buzzer that buzzed when the
lights were left on and that solved the problem .

When I got to my brother's city three years later, the dealer was out of
business. Maybe because they didn't know how to fix a car.