In article ,
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?

Not nuts... clamps :-)

The trick here is the fact that the clamps are tightened down
well when you install the battery cables. The tightening pressure is
sufficient to force the surface of the metal clamp into direct contact
with the (soft) lead battery post, squeezing all of the grease
out of this area.

You end up with just about the same amount of direct metal-to-metal
contact between post and cable-clamp that you would if you hadn't
used grease. The grease which remains, fills what would otherwise be
air voids between the post and the clamp. The grease will block
oxygen and moisture (including leaked battery electrolyte) from
penetrating the connection and thus will help preserve the quality of
the metal-to-metal connection.

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

http://www.w8ji.com/dielectric_greas...ive_grease.htm

"In single low-voltage terminals or connections, such as metal-to-metal
joints, grounds, or battery posts, almost any pure grease of light
viscosity will be acceptable. Caution should be used with greases
containing metallic powders to be sure any metal is compatible with
the embedded grease metal. Connection enhancement from embedded metal
powder is very minor, if it exists at all, and there is increased risk
of bad connections if the metal powder has any interaction with the
base metals."