I bought two new DuraLast Gold batteries at AutoZone last year, maintain them on a smart charger at 13.2V float, and just added a little water to them. I was under the impression that you should "equalize" them when you add water so that the battery acid mixes and doesn't stratify. I put the charger on equalize, it runs it up to 15.5 volts, all the cells in two batteries are bubbling except two on the left of the first battery (facing the truck). I'm not an anything expert but it seems if they aren't bubbling, they aren't taking any charge? Any thoughts?

 

What does your hydrometer or refractometer say?

Pop

 

Good idea Marv, I will pick one up tomorrow.

 

All of the cells should bubble or "Gas" equally. The 15.5 is too high a voltage to equalize the batteries. The system voltage 14.8 is high enough to get the equalizing done. Try disconnecting the batteries for an hour or so, and measure the voltage across the batteries. the voltage should be about 12.3 volts in an open circuit condition. If you read something like 10.3 vdc, then you have a shorted cell. If thats the case, both batteries should be replaced at the same time. The reason being that the internal resistance of the batteries have to be equal. As batteries age the resitance goes up.
Nick

 

More good info. Got busy on the trailer today, jury duty tomorrow but by next week I'll be checking it out. Batteries as I said only a year old but have i think a 7 year warrantee. thanks again

 

I've been starting to notice some evidence of moisture leaking out from the battery caps, and the first bits of build-up on the cable terminals. (Previous owner installed the batteries). Haven't tried a hygrometer on either battery yet, just wondering what that might moisture might indicate?

Replacing both simultaneously is a good tip, but I think now that would mean for me that it will take a little while longer.

 

I've been starting to notice some evidence of moisture leaking out from the battery caps, and the first bits of build-up on the cable terminals. (Previous owner installed the batteries). Haven't tried a hygrometer on either battery yet, just wondering what that might moisture might indicate?

Replacing both simultaneously is a good tip, but I think now that would mean for me that it will take a little while longer.

 

First I'll answer the post I started: I bought a hydrometer ($5.00) and confirmed what I already knew and didn't want to deal with - one battery had a dead cell. Of course AutoZone replaced it, but only one battery since the other tested good. Never mind the fact that batteries should be replaced in pairs and that the one battery with the dead cell most likely damaged the other battery as well.

Now for moisture on the battery caps. I would simply check the water level in the batteries, fill if needed and maybe, clean the batteries and just maybe suspect (and check) that the charging voltage is too high? I think it's supposed to be 14v or a little higher. As far as corrosion on the terminals, I would again simply take them off, clean them well, put Vasoline on them and reassemble. Unless the batteries are old, or you find something wrong in the process, I would normally expect them to lead a normal life to a ripe old age. I keep mine on a "smart charger" that keeps a float voltage of about 13.2v all the time. If they sit unused, I equalize them every month or so. I've had good luck with my other truck's batteries and with the trailer batteries, and again attribute that to the smart charger, and checking the voltage and water levels on a regular basis. I also don't take a lot of chances and replace them in any event about every 5 years.

Hope that helps

 

Oh Yes. I have never had a dead cell on any of my car/truck batteries that I've maintained and I ain't no spring chicken. I did have one go on my Harley a few years ago, but motorcycle batteries are all over-stressed. So I was a little shocked when after 1 year I had a dead one on these top of the line AutoZone batteries.

 

Take the dead battery back and see if you can get credit on the good battery so you can start with two new batteries again. 15.5 does seem high to me. I've never had batteries at anything over 14.5 unless I was using a charger to try to start it.