Wet battery terminal

NORMAL condition. Normal color change. Don't forget negative battery plates are made of different material than positive plates. Causes interesting things to happen.

Gdetrailer wrote:

jeff14 wrote:
Both of the positive terminals are darker than the negative post and are damp. I see some corrosion on the wire end that goes over the battery post but not the negative. They are both 12v , are 2 years old and are full of distilled water. they do charge up when they are hooked up to the trailer. Can anyone tell me if something is wrong?

You need to REPLACE BOTH batteries.

The seal around the positive terminals is DAMAGED and the electrolyte (acid) is creeping up the positive terminals.

I had that happen to a tractor battery. No matter how much I cleaned and greased the terminal it would turn black in a couple of days. I even tried the anti corrosion felts which often work well, they didn't in this case.

The only solution is to replace.

Gtetrailer MAY be right, but it may be just venting from hard charging as others have suggested. Clean as suggested and watch carefully. If the corrosion reappears quickly, then you likely have a leakage issue and they should be replaced before the acid does real damage.

One of the starting batteries in our DP had the + post corroding. I cleaned it every couple of weeks until we returned home and then replaced them both. They were dated June 2007 so I wasn't too upset!

jeff14 wrote:
Both of the positive terminals are darker than the negative post and are damp. I see some corrosion on the wire end that goes over the battery post but not the negative. They are both 12v , are 2 years old and are full of distilled water. they do charge up when they are hooked up to the trailer. Can anyone tell me if something is wrong?

You need to REPLACE BOTH batteries.

The seal around the positive terminals is DAMAGED and the electrolyte (acid) is creeping up the positive terminals.

I had that happen to a tractor battery. No matter how much I cleaned and greased the terminal it would turn black in a couple of days. I even tried the anti corrosion felts which often work well, they didn't in this case.

The only solution is to replace.

I too suspect some venting at the battery caps. Perhaps they are being overcharged by your converter. If you only have the single mode type converter that puts out a constant 13.6VDC it may cause your battery over time to boil out some battery fluids. I would definitely keep checking the battery fluids once a week to see if they are maintaining the proper fluid level in the cells.

just my thoughts

Roy Ken

if you use baking soda be very careful you don't get it into the vent holes of the caps, you will ruin the battery. best thing to do is use hot water and a wire brush. battery stores don't use baking soda, all they use is very hot water. it will get the white stuff off the posts

What type of batteries are these? I suspect that there is some venting of electrolyte going on either because there is a leak in the casing by the positive posts or because the batteries are designed to vent there when they are being overcharged. Spray some baking soda solution on the wet posts and I bet you will see a reaction. What type of charger or converter do you have and how long are your batteries usually on it? If it does not have a float stage then it may be overcharging your batteries. It could also be that your batteries are overfilled. Good luck with your investigation.

Miles

How full? Electrolyte should be just below the bottom of the fill tube.

Jim

Get one of these: Battery terminal cleaner They are available a lot of places, this is just one.

It will aid in cleaning battery posts and the cable connectors to the posts very well and will last a very long time. I use a little water and baking soda mixture with it and the parts come very clean and shiny.

Hi,

Give it a good cleaning. how to clean

Be sure to go to GM and get some battery spray. You want the kind that leaves a waxy finish.