Did I screw up the battery?

[Steve L22188]

Knew I was going to be away from the boat (1988 O'Day 302) for about a month so went up on Saturday (in 106 degree heat!) to check it out before leaving town. Discovered one of the three-hole cells in one of the two batteries was very low - a couple of the plates were sticking out of the fluid.

Of course, I had no distilled water on board and the marina store had no distilled water (amazing). So I ended up using bottled water to refill that very low cell and to top off all the others.

Did I shorten my battery life? Have tried to always used distilled water - but is that really necessary?

The batteries are from Sam's - deep cycle. They're about 5 years old, on a charger, and they have given me very good service. I suspect they are near the end of their natural life.

Know there are some battery experts here - can you let me know if I should expect a problem?

Thanks.

 

[anchorclanker]

Your supposed to use distilled. High mineral content in water is the problem. If the water you used was low in minerals, and/or you didnt use much, it may or may not ruin the battery. After adding a large amount of water the battery should be charged at a low setting.

Honestly, I would be more concerned why one cell was down and not the others. The battery may have already been toast before you poured in the "bad" water.

 

[MLampner]

It depeneds on what the bottle water is. If it was filtered tap it shouldn't be much of a problem, if spring water it will depend on its mineral content.

 

[jepomer]

The replacement water quality is of less concern than the original cause of the unequal fluid level in the cells. The replacement water will accentuate the original problem.

Good thing Sam's batteries are relatively inexpensive. 5 years life is not too bad in that respect.

 

[Maine Sail]

At this point the water is the least of your worries. But to answer the question yes it does matter what type of water you use. It needs to be demineralized water either by RO (to a very low TDS) or Distilled.... The problem with RO water is it very rarely has a low enough TDS level for a battery. Distilled water is $1.39 and can even be purchased at Wal*Mart so no reason not to keep a gallon on-board or at home....

At this point get as much mileage as you can and replace them when they kick. I would guess you have a charger that is not as smart as it should be.

I will say this once again....

ALL BATTERY CHARGERS THAT ARE TO BE LEFT "ON" FOR LONG PERIODS OF TIME SHOULD HAVE A BATTERY MOUNTED TEMP SENSOR, AT A MINIMUM, OR THEY ARE NOT "SMART"!

Any charger calling itself "smart" that does not have a temp sensor that can be physically mounted directly to the battery negative post is simply misleading marketing BS/snake oil. That said you also need a charger capable of equalization cycles as the water level should go down evenly...

Bulk, absorption & float cycles simply do not make a charger "smart".... 5 Years is darn good life if using a non-temp compensated charger....