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Senior Moment
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Hello All,

In a similar battery thread btrayfors responded:

Q: What can I do to reduce sulfation to a minimum?
A: Keep your batteries fully charged whenever possible, exercise them occasionally, and equalize them every few months.


Seems all good, except I wonder how do you equalize your batteries?

Thank you
michael
 

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What is equalization? Does it have something to do with having multiple batteries in a bank or multiple banks? We probably all have both, with unequal banks.
 

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The term, "equalization", when applied to storage batteries refers to a process whereby you intentially provoke an "over-voltage" charging condition for a fixed period of time. This tends to produce bubbling sufficient to stir up the electrolyte. It helps also to knock loose PbSO4 crystals off the plates, thereby increasing battery capacity previously lost. And, of course, it tends to "equalize" the specific gravity of each individual cell in the battery or battery bank. Hence, it's name.

For a 12V system, an equalization charge is about 15.5-16.0 volts for several hours. Consult your battery manufacturer for specifics. Trojan batteries have a white paper available which provides good information.

Some AGMs can be equalized, too. See the manufacturer's recommendations.

Gelled batteries are not normally equalized, since they are quite voltage sensitive, and high voltage can damage them permanently.

As the previous post said, some modern battery chargers have an equalization cycle, either manual or automatic. Also, some smart regulators, like the Balmar MC-612, have an equalization setting (manual) so you can equalize your batteries using the engine's alternator.

Batteries should be inspected carefully before equalizing to be sure their electrolyte levels are sufficient. If you have HydroCaps, these need to be removed before equalizing. WaterMiser caps can be left in place.

Sensitive electronic equipment should be turned off during the equalization phase, since voltages can be considerably higher than they were designed for.
Bill
 

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Bill's recommendation to see the battery manufacturer's recommendation regarding equalization is really important. Many AGM batteries also should not be equalized.
 

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The True Charge 20+ manual says that it can do equalization and apparently this should be done every couple of months with moderately used flooded batteries. The fun part seems to be that it is a manual process. The cycle should be stopped when "the specific gravity in each sell reaches 1.265 and remains constant at that level". Running the cycle too long can do permanent damage to the batteries. It doesn't say whether each battery should be done separately or if I can do my 3-battery (wired in parallel) house bank can be done as a unit.

I like maintenance as much as the next guy (well, maybe not so much), and maybe if I was a live-aboard I would do this as part of a routine, but as a mostly weekend sailor with maybe two one-week trips per season, this is not going to happen. I don't see myself hanging upside down in my locker checking the specific gravity of 18 cells (24 if I do the starter battery) repeatedly until they remain constant for some unspecified period of time. AGMs here I come.
 

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Joel...you can do the whole bank at once. Just fully charge the batteries first, then EQ them for 6-8 hours with the caps off. You don't have to be overly anal about it contrary to the instructions. Make sure you allow for some ventilation while the process is going on.
 

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Telstar 28
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Don't forget to check the water levels before and after equalization. :)
 

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baDumbumbum
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Joel: Batts in parallel strings are prime candidates for equalization, if the practise is advised by manufacturer. Parallel strings let a weak batt 'hide'; it will soon become irreversibly sulfated and act as a drag on the others, like a weak horse on a draft team. So if you have parallel strings, equalize frequently.

PWM controllers are really good for EQ, by the way. They can blast off the sulfation without badly overheating the battery or boiling away all your water. Many use a shorter cycle because of that. It's nice if your controller lets you tweak time, frequency, and voltage for EQ.
 
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