Mixing brass and A4 on battery terminals

[Boater Sam]

I think the vaseline/ grease smearing is an old school protective tip , back when the battery leaked acid from around the post. Personally not seen the occur on any modern constructed batteries.

It was Holts Nocrode at one time to prevent terminal clamps rotting. I don't think you can buy it anymore. Oddly it never interfered with the post making good contact with the clamp, even with those horrible hooded lead connectors with one self tapping screw which BMC loved for many years, Morris 1000s, early minis, A30 and A35 and A40 etc.

 

[lustyd]

But I do like to smear it around to keep water and salt out.

I use a hull and deck for that, but each to his own ?