"Overcharge or Bad battery"

Searched but to no avail...
I have a delco, 3 terminal alternator installed. Also have a new dura-last battery.
Noticed when the outside temp reaches 100 or greater, and after a 8-10 mile
run, the battery starts seeping around the fill plugs..
The alternator is putting out + or - 14 volts at rpms over 1000. Just a tad over 12
when at an idle. Could the battery be the problem, or the alt. putting out too much ?
Don't like the acid eating up my jeep..

 

+or- 14 volts? How much +or-? should be in the 13 1/2 volt range average unless using lots of electrical accessories drawing down the battery. 100 plus degrees will cause the battery electrolyte to expand (basic physics, liquids expand under higher temps) and that could cause the seepage you're experiencing if the battery is over full. I'd pull the caps and check the levels in each cell first.

 

The voltage ranges close to 14 volts while driving. The battery is a smaller type, so it don't hold
as much liquid as the original. I was wondering if that might be part of the problem also. I don't use
any thing other than lights when its dark.

 

With the lights on I could see the charging system pumping out 14 or a touch more volts when driving. Just depends on the load. Most likely the battery is heating up and the fluid is either expanding and pushing out some or outgassing and re-condensing on the battery. Might consider having the battery tested independently to make sure it isn't sulfated causing this issue. Regardless I'd protect the terminals so they don't corrode.

 

I have been told a rule of thumb, that when a battery gets warm or hot, it is being overcharged. In other words anything less than that is an okay charge rate. An easy field test.

A simple thing like a dirty wire connector can fool the charging system into over charging.