I do not drive Lightning much on street, so in off season I check the eye for green. If not I charge it. Today I check the eye, and the eye is bright RED. Never seen anythingbut green eye in a battery. Tell me it is not what I think it is. Truck still starts fine.

 

Mine did that last winter. Took a good hour drive to make er green again. Been green ever since.

Rich

 

Mines Green on the sides, with red in the center... what that hell does that mean?

 

The red/green eye is in effect a hydrometer that is measuring the specific gravity of the battery cell that it is in. The specific gravity relates directly to the voltage in that cell. A red eye means that the voltage in that cell is low. This could mean that this particular cell or the battery is bad or that the battery is low on charge or bad. The fact that it is green doesn't necessarily mean the battery is good, only that the cell is at the correct voltage (other cells could be bad). Obviously this gets into the whole electrical system question do I have a electrical drain problem, is my charging system working properly? Your voltage guage inside the truck can show that the alternator is charging but it might still have bad diodes (not converting the A/C into DC which the battery can store. I don't mean to sound like these eyes are worthless but they aren't a great deal of help. If the truck has been used regularly then there is no sense in speculating. Take it to an AutoZone/Sears and let them check it. I believe both of these sources sell decent batteries and do the check for free.

 

Used for years on my motorbikes.
Works great on cars also.
http://www.accwhse.com/batteryt.htm