equalizing even though regularly reaching full

[CSY Man]

My batteries are "bulging" on the side. I would think this indicate they are getting old, but have found no official guidance on it. (Trojans T-105)
Anybody?

[Stu Jackson]

Originally Posted by CSY Man

My batteries are "bulging" on the side. I would think this indicate they are getting old, but have found no official guidance on it. (Trojans T-105)
Anybody?

How old are they? Doesn't really matter though.

I recently replaced a house bank ( 3 130 ah Grp 31s). One case was bulging and the vendor said, "Well, that one's toast, but let's check the other two."

If it looks wrong, it usually is.

That's the unofficial version.

Need more?

[Stu Jackson]

That is a much more detailed question, and, as you note, completely different than the original one. No shame on you, just trying to be helpful in the context of the OP, as compared to this completely different one.

If you are truly reaching a full charge, completely full, after every day, then you are treating your batteries very, very well.

If you are within the 50-85% "cruisers charge" then a periodic equalization is a very good thing to do if you can get to shorepower or use what you have on board.

All the best.

Originally Posted by zboss

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.



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.

[CSY Man]

They are about 4 years old.
I have seen batteries bulge before, but again, no official wisdom on it.
I thought it was part of the aging process, we all get a middle age spread over time.
As far as the batteries being "toast" for bulging, news to me and they seem to function ok as far as taking a full charge, holding a full charge, etc.
Will measure the specific gravity today or tomorrow to get a better idea of the condition.
Wish I could equalize but the onboard charger does not have such a program:
ZIVAN NG1 (unless it is automatic, but pizz-poor manual with the charger, does not mention no equalization program )
Doubt my trusty 6/12 volt car charger can be used for it either.
Anybody know of a portable charger that can be used to equalize the batteries?
8 Golf Carts, series and parallel for a 48 Volt system.

[CSY Man]

swollen batteryImmediately remove the battery from the device. A battery becomes swollen as a result of overcharging. Excessive current will flow into the battery after the battery has reached a full charge. The constant current will cause decomposition of the water in the electrolyte and premature aging. At high rates of overcharge a battery will progressively heat up. As it gets hotter it will accept more current, heating up even further. This is called thermal runaway and it can destroy a battery in as little as a few hours. The heat will cause the battery to expand.

[Sternwake]

I have observed that my single flooded group 31 USbattery, fed by 198 watts of solar to 14.9v until current drops to 1.4 amps, and then held at 15.3v for the rest of the afternoon, will have SG drop, on some cells to 1.255, while some other cells are 1.270 after 14 cycles in a row in 14 days.

At which point I will raise maximum allotted voltage to 16V, and it will take a minimum of 6.2 amps to bring and hold battery to 16V. Then SG maxes out at about 1.285, depending on electrolyte level at the time, about 45 minutes to an hour at which point amps have tapered to 3.8 amps when newer, and now about 4.9 amps at its greater age.

The more cycles I go without 16v, the wider disparity between the cells and the lower they read on the hydrometer and the longer amount of time they require at 16V before SG no longer rises.

Voltage under load is much improved during the next discharge cycle after 16v is applied for long enough to max out SG.

Yes I know these voltages are rather extreme, but I worked upto them slowly testing and experimenting, and this battery now has 400+ cycles on it, and provided 35 to 70 AH each and every night often at rates exceeding 6.5 amps.

It has obviously lost capacity and nearing the end of its life, but I am going to keep cycling it until it can no longer keep my Vitrifrigo c51is fridge below 34F, or shorts a cell.

[monte]

Held at 15.3? Shouldn't the float voltage be lower than bulk absorption voltage ?

[Sternwake]

Yes normally. I use 15.3v as a finishing/topping charge, as 14.9v can't get this particular battery up where it needs to be after a cycle and capacity walks down quickly cycle after cycle.

The rare times I utilize shorepower overnight or do not cycle my batteries deeply, I attempt to close in on USbattery's recommended float voltage of 13.06.

[zboss]

Originally Posted by Stu Jackson

That is a much more detailed question, and, as you note, completely different than the original one. No shame on you, just trying to be helpful in the context of the OP, as compared to this completely different one.

If you are truly reaching a full charge, completely full, after every day, then you are treating your batteries very, very well.

If you are within the 50-85% "cruisers charge" then a periodic equalization is a very good thing to do if you can get to shorepower or use what you have on board.

All the best.

Stu.. Thanks. and you are correct... different question.

I think the only way to know if we are truly reaching a completely full charge is to test the cells every day. Who does that?