Help with Battery Terminal corrosion and why

I have an AGM battery in my camper and the posts corrode anyway - just clean and regrease them once in a while.

And when I tow my Jeep I have to turn the key one click to unlock the steering but it doesn't turn on any power in the Jeep so the battery doesn't run down.

Sloop Smitten wrote:
To me the presence of excessive corrosion is a tell-tale sign the battery is nearing end-of-life.

x2 Time for a new battery.

Am old trick for diminishing the amount of corrosion is also felt washers, If you have a post type battery, that will slow down the corrosive effect of the acid outgassing.
Personaly I would glady spend the extra money on an AGM battery.

Replace your battery with an AGM battery .
They do not leak and will not corrode your terminals .
I removed my battery tray which was corroded and I followed the instructions in this video link .
http://www.youtube.com/watch?v=Bt_Z7TlbFqM
I followed his instruction and I did very little scrub work .
I then painted my steel battery tray with black derusto .
I picked up and Exide Edge AGM group 78 battery for $ 140 plus deposit .
This solved all of my corrosion issues .
Plus the Edge AGM recharges faster and will take a deeper drain than the conventional lead acid wet cell .

On the towing issue, when I flat tow my Ranger on the tow bar, I disconnect the battery, since it also needs the key in the run position to keep the steering column from locking.

I use a seperate, portable towing light system that connects directly to the truck I tow the Ranger with, so the Ranger does not need any battery power going to it's own lights while being towed.

A old school trick that works good with mild cases of corrosion is to silicone pennies to the top of the battery. Corrosion will take the path of least resistance. I had success with this method on my old 99 F250 that had corrosion eating the battery hold downs.

I would cleanbthe terminals well. I use wire plumbing brush they use for copper pipe. Then use electrical grease on connectors.

Adding on to what Donn offered, acid corrosion is almost always related to outgassing while charging due to micro-fissures around the cell caps and battery posts caused by vibration over time or, in the usual case with a Jeep, due to excessive vibrations due to off road use. You can reduce it by rubbing some grease on the post, and around the post, but in the long run rough use, or time, will eventually result in microfissures leading to an accumulation of corrosion. This is why older batteries corrode more than newer batteries. To me the presence of excessive corrosion is a tell-tale sign the battery is nearing end-of-life.

Corrosion is always caused by battery acid. Whether by direct contact or by battery off gassing. IF you have that much damage, then your battery is discharging really heavy amp loads. In other words boiling the liquid as it is discharging. To help prevent damage in the future, apply a liberal amount of grease when you put things together.