equalizing even though regularly reaching full

[zboss]

Folks,

Is is really necessary for us to equalize our FLA even though we reach our full voltage most days?

- z

[Maine Sail]

Originally Posted by zboss

Folks,

Is is really necessary for us to equalize our FLA even though we reach our full voltage most days?

- z

A "full voltage"? Can you expand on this...

[CSY Man]

Yes, it should be done now and then.
Like taking vitamins, it can't hurt and probably will do you good in the long run.

[colemj]

The only reason to equalize is if the individual battery cells have different specific gravity readings. Then equalize only until they read the same.

Mark

[monte]

I think it is (in general ). Our recent experience in a similar situation is here.
Battery sulphated? - Page 2 - Cruisers & Sailing Forums
I just added the last comment re: noticing an improvement after equalizing.

disclaimer: I'm an electronics dummy and pretty much solely rely on the advice these guys give me ^^^^ , so perhaps your circumstances wont be the same as mine and perhaps a simple difference between your system and mine will make it a totally different ball game!

[sparrowhawk1]

Equalization is to I believe the proper word is desulphate, every time you discharge your batteries and a lot if you discharge them deeply and leave them discharged for extended periods the plates get coated. Equalization removes this buildup . It's my understanding that it's good to do it as regular maintenance and if done properly will not harm your batteries even if you have little build up. The problem I've found is finding an agreement of how high to take the voltage and for how long. Always monitor your batteries when equalizing and make sure you have proper ventilation. I've had to edit this 3 times but very important do not operate anything that will be harmed by the higher voltage while equalizing

[zboss]

Originally Posted by Maine Sail

A "full voltage"? Can you expand on this...

Trojan says that a full charge is 14.8 volts, which my batteries hit almost every day. We use a Balmar Smartguage.

We do equalize but not regularly. My genasun controllers claim they auto equalize every thirty days but I've not yet been able to observe this happening.

[monte]

14.8V is the maximum recommended bulk charge rate. Hitting and sitting on 14.8 just means they're accepting the maximum voltage and doesn't reflect on the actual state of charge.
Trojan should also state the SOC as per the % similar to above so check that.
What voltage do you generally see on your BM late at night/ early morning before the solar kicks in? That's possibly a better indication of actual SOC. Keep in mind the actual SOC can't be determined unless the batteries are
full charged at the dock for 24 hrs
Disconnected
Had a load applied to remove surface voltage
Left for 24 hrs
...which isn't going to happen on any regular basis
It's probably worth getting a hydrometer to test the specific gravity of each cell as suggested above, which might be more valuable in keeping track of the batteries health as well.

The solar controller equalisation mode will only happen when there is enough power generated to do so, which is unlikely unless plugged in at the dock and batteries fully charged. I think it's also very dangerous to leave it in auto mode as equalisation should be monitored carefully.
Our last boat I left it in auto mode initially. Exactly one month after installing it we were motoring along and I went below to the strong smell of hydrogen gas, as well as battery monitor alarms going off. No hatches were open. This could have easily caused a fatal accident, especially if someone was sleeping in the berth above the batteries, or the stove was lit.

[Stu Jackson]

The Ample Power Primer http://www.amplepower.com/primer/primer.pdf

[sailinglegend]

Originally Posted by zboss

Trojan says that a full charge is 14.8 volts, which my batteries hit almost every day. We use a Balmar Smartguage....

I'm sure Trojan don't actually say a full charge is 14.8 volts!

When a battery first reaches 14.8v it is probably only at about 80% State of Charge, if the charging source is correctly matched to the size of the battery bank. This Absorption voltage should be held long enough until the batteries are nearly fully charged when the charger should automatically drop down to a lower Float voltage to finish the charge. That’s the “simple” theory of charging.

You have a SmartGauge so what is that telling you about the SoC when you first hit 14.8 volts, and how long does it take to reach 100%?

Batteries need to be Equalised when they have been left discharged for too long without FULLY recharging, this can lead to permanent sulfation. “Sulfation” is the normal formation of Lead Sulfate crystals on the lead plates as a result of the chemical reaction of the battery discharging, not of any mistreatment of the battery.

Charging converts the Lead Sulfate back to Lead and Sulphuric Acid, which is why the SG value goes back up again. If not 100% recharged every 2-3 weeks any Lead Sulfate Crystals not converted back to Lead will slowly harden and will provide a permanent layer on the lead plates reducing the Ah capacity of the battery. Equalisation may remove some of the hardened crystals, but not if they have been left to harden too much.

Battery manufacturers recommend monthly equalisation if batteries haven’t been fully charged to 100%. This can’t be done on most sealed leisure batteries because it causes too much water loss.

[Maine Sail]

Originally Posted by zboss

Trojan says that a full charge is 14.8 volts, which my batteries hit almost every day. We use a Balmar Smartguage.

We do equalize but not regularly. My genasun controllers claim they auto equalize every thirty days but I've not yet been able to observe this happening.

It is not just hitting 14.8V that makes the battery full. You then need to hold it at 14.8V for a full absorption cycle until the net accepted current flowing into the bank, at 14.8V, has diminished to at least 2% of the banks Ah capacity. While 14.8V & 2% net current is not chock full it is close enough for cruising full...

Depending on the size of your charging source and level of sulfation in the bank you could easily be hitting 14.8V at an SOC as low as 65%... Just because the bank has hit 14.8V it does not mean it is full...

[four winds]

Disconnected during equalization is good advice or maybe battery switch to off position.

At couple of months ago I did not realize the chartplotter (Garmin) was left on over night and equaization the next day killed it dead.

Lucky for me, I practice "instant forgiveness" so no curse words were used and my self esteem is intact.

[Stu Jackson]

Why Going Into FLOAT is NOT Full

Why Going to Float is NOT Full

It appears that you may want to revisit your understanding of basic battery charging.

The link I provided to Ample's primer explains it well.

In addition, all the regulator manuals do so also. Go to www.balmar.net and download, for example, the MC-614 regulator manual. There is a whole page with descriptions and a chart showing the various "stages" of charging.

Good luck.

[zboss]

Originally Posted by Maine Sail

It is not just hitting 14.8V that makes the battery full. You then need to hold it at 14.8V for a full absorption cycle until the net accepted current flowing into the bank, at 14.8V, has diminished to at least 2% of the banks Ah capacity. While 14.8V & 2% net current is not chock full it is close enough for cruising full...

Depending on the size of your charging source and level of sulfation in the bank you could easily be hitting 14.8V at an SOC as low as 65%... Just because the bank has hit 14.8V it does not mean it is full...

During bulk charging we see maybe 15-28 amps going into the batteries as the system is ramping up depending on solar and wind, sometimes more but always enough that the the Balmar indicates a SOC of 100% by about 2 PM.

We usually see about 5 amps going in before it goes into float, where it then maybe gets down to 1.5 amps on a 520 Amp/hour system.

Originally Posted by Stu Jackson

It appears that you may want to revisit your understanding of basic battery charging.

I fully understand these concepts Stu... SORRY for not providing every detail of my charging regime... shame on me! I did not believe it was germane to the question. Maybe I should have said "Assuming a theoretical full charge every day, is it really necessary to equalize the batteries?"

This question arose because I read the following on wikipedia; please no lectures on the validity of wikipedia - its not really important to this conversation outside of causing a question in my mind to arise.

"In addition, the sulfate portion (of the lead sulfate) is not returned to the electrolyte as sulfuric acid. It is believed that large crystals physically block the electrolyte from entering the pores of the plates. Sulfation can be avoided if the battery is fully recharged immediately after a discharge cycle."

And I was wondering... IS THE LAST SENTENCE TRUE?

Mainsail hinted that "full cruising charge" is not "full charge" thus probably requiring a periodic equalization but I have every indication that I am reaching 100% state of charge for my batteries based on my Balmar. If in fact I am reaching the 100% equalization, I can reduce how often I equalize.

[sailorboy1]

Originally Posted by zboss

Folks,

Is is really necessary for us to equalize our FLA even though we reach our full voltage most days?

- z

If most days reach full charge based on the amount of acceptance current, I don't feel you need to equalize at all. But the only way to really know is to fully charge the batteries and then check the specific gravity of all the cells for comparison.