Battery Noise????

[Alden68]

These tend to be the posts I make right before I shell out major boat bucks..........hopefully one of you can save me.

Here is the scenario:

I have 3 group 30 wet cell batteries in my house bank with a 100 watt solar panel.

Today my solar charge controller entered it's "bulk" stage where it puts 14.5 volts into the batteries for 2 hours. Toward the end of the stage I put a multimeter on the batteries to verify the output. All was fine at 14.5 volts however......I though I heard the faintest sound of .......boiling water!

Sure enough, when I put my ear up to the battery, I could hear a sizzling/boiling sound. VERY faint, but there nonetheless. The batteries were not warm, bulging or anything else out of the ordinary, however I did disconnect the solar panel until I figure this out.

Is it normal, with a wet cell battery, to hear the elocrolyte doing it's thing??

Thanks....

[CapnHand]

It's normal. The bubbles you hear are hydrogen gas being produced. As long as the batteries are in a well ventilated area with no souce of ignition, all should be fine. It's a good idea to check the electrolyte levels periodically after charging.

[sailingdog]

As CapnHand said... it is perfectly normal for your batteries to be generating a small amount of hydrogen gas during the charging process. This is why you have to monitor the water levels in wet cells.

[Alden68]

What that is good news. What is the general rule of thumb for checking the electrolyte?

[sailingdog]

The water level has to be above the plates.. or the plates will sulphate and the battery will die. You have to use only DISTILLED WATER for the batteries, since the mineral content of tap/spring water can seriously shorten battery life.

[CapnHand]

Originally Posted by sailingdog

The water level has to be above the plates.

Just above the plates, about 1/8". Too full and the acid will bubble out next time the battery is charged or spill out when the boat is heeled. More info here Crown Battery Manufacturing Company :: Support : Deep Cycle Battery Care or check with the manufacturer of your batteries.

[Alden68]

Quote from the Crown battery link;

"Batteries should be watered after charging unless plates are exposed before charging. Plates should be covered by approximately 1/8" of acid if exposed. Check level after charge."

With my solar panel the batteries are always charging. I cant assume that I have to check the batteries every day....I'd rather run on a treadmill to keep the chartplotter on.

How often as a GENERAL rule? Twice a season (a NE season)?

[btrayfors]

It depends. On ambient temperature and humidity. On charging regime. On condition of batteries. On battery usage.

To cut down on water loss from flooded batteries, use HydroCaps or WaterMiser caps. Both easily findable on the web. These are wonderful little devices which really work.

Bill

[CapnHand]

Originally Posted by Alden68

How often as a GENERAL rule? Twice a season (a NE season)?

Once a month should do in most cases. Go for shorter / longer periods based on what you see.

[sailingdog]

Generally checking the batteries, if you have a good charger, once a week is sufficient. If it seems stable after a month, then you could probably go to once-a-month checks. However, if you change your charging setup, I would check weekly again, until you know how it affects the electrolyte levels. If you have a bad charger, or one that is mis-adjusted, you may have to check every day...but that isn't normally the case.

The hydrocaps or water miser caps are a good idea as well.