Forum Discussion

swimmer_spe's avatar
swimmer_spe
Explorer
Jul 16, 2021

Chasing the green monster away

I swapped out a battery for a new one. The old one is fine, but I needed an extra Deep Cell battery, so I figure I'd put the new one on my trailer. For some reason, it would not work.

Then I saw the Green Monster - corrosion. The +ve connectors were covered in corrosion under it, so out of view. I ave cleaned them and now it works well.

So, now I am wondering whether I should replace those connectors, or if there is something else I can do to keep the Green Monster away.
  • I made it a point to study the mechanics of battery post and terminal corrosion and this is what I learned (high points)

    • Much corrosive elements issue from the cell filler vents
    • But invisible to the eye corrosive gas vents at the junction between the battery case and lead terminal posts
    • Felt disc "washers" saturated with oil effectively seal the posts
    • But the design of the traditional marine/deep cycle combination post is so large the felt washers cannot be used
    • Therefore reliance on a sealant alone must be used
    • The sealant must be forced into place through tight clearances
    • The entire area around the terminal must be "glopped" with sealant
    • It is not only liquid electrolyte that corrodes
    • Hydrogen sulfide contributes much of the corrosion
    • Out of the vents the gas rises but little impedes its rise
    • From the post case junction, the entire lug or terminal gets dosed. The underneath of the terminal, which cannot be easily seen
    • Decades ago Petroleum Jelly was recommended as a viable sealant
    • Today's much hotter underhood environment turns the jelly into a thin liquid, making it useless
    • Chassis grease withstands heat well but people complain about the mess to hands and clothes when under the hood
    • Clear silicone grease is adequate and avoids contaminating hands and clothing...it washes out easier
    • When applying protective sealant the underside of terminals must be attended to so as to not leave gaps. This is critical
    • A solution of baking soda in very hot water can work 10 times faster than it does in cool water
    • Wear splash goggles. You have but two eyes.





  • The trailer battery is not under a vehicle hood, so it won't get the higher heat. I'd use the petroleum jelly.
  • 3_tons's avatar
    3_tons
    Explorer III
    Hey Mex, that was a great tutorial!,

    I was just thinking, how about a little baking soda mixed in with the grease??

    3 tons
  • Check the issue more often. Increase service and precautions as needed. New battery may present less issue.
  • 2112's avatar
    2112
    Explorer II
    That's good information Mex.

    You commented on this several years ago. At that time I was having terminal corrosion issues on my truck battery. I didn't realize a quality battery would leak between the plastic case and lead post. I sealed around the posts using Dow Corning 732 silicone adhesive and problem solved. Now sealing around the posts is part of installing a new battery in our car and truck.

    For some reason I don't have the same issue with my boat and camper batteries so I don't bother sealing them.

    Thanks
  • wa8yxm's avatar
    wa8yxm
    Explorer III
    Top left product is protectant. Not sure about the clearner to the right but I sued teh protectant it seemed to help.

    Get it at Link, Or any auto parts store. may be a different brand but CRC is a very old established company.

    assorted battery sprays

    Moderator edit to fix link.

  • As usual, MEXICOWANDERER nailed it.
    My only imput is that over the years I have found a little corrosion on the battery terminals can cause all kinds of problems and weird things to happen.
    Whenever you have electrical problems, clean and tighten the battery terminals before you start the diagnostic process.
  • I like these products.

    The NCP2 is VERY thick, and does not liquify like petroleum jelly and some greases will.







    :):)
  • rexlion wrote:
    The trailer battery is not under a vehicle hood, so it won't get the higher heat. I'd use the petroleum jelly.

    It works !

    Use a generous amount !!