Battery question

[drew238]

For some reason, one cell in both of my deep cell batteries always dies. This is just from testing with one of those .99 turkey baster type testers. Even after a full charge, these two cells never have any life. The water levels are fine in all of the cells.What might cause this and how much affect does a dead cell have on the overall performance? Should I just replace the two?

[MarkW]

Replace them. One cell in each battery going bad can cause you to have some problems.

[highoctanehookset]

This is some information that I rean across. I have heard that vibration can cause alot of problems..also deep discharging.

WHAT ARE THE MOST COMMON CAUSES OF PREMATURE BATTERY FAILURES?

Loss of electrolyte (which account for over 50% of the failures) due to underhood heat or overcharging
Deep discharges (leaving your lights on)
Misapplication or using an undersized battery
Undercharging or loose alternator belt
Excessive vibration (due to a loose holdown clamp)
Using tap water
Corrosion
Freezing