Battery Life and Equalization Charge

[Curtis]

I have a house bank of 3 12V flooded wet cell lead acid batteries that have an advertised 20 hour capacity of 130 amp hours each (total of 390 amp hours). They are connected in parallel.

At the dock we use a ProMariner ProTech 4 50amp charger that I leave on all the time. This charger is bascially a 3 stage (fast, absorption, and maintenance).

The batteries are about 2.5 years old and have not been abused (only one full discharge).

I have a Link monitor so I'm sure they are getting fully charged. The Link is reporting a CEL of 93%.

The voltage is dropping rapidly from a full charge. A constant 10 amp load will get us down to less than 11 volts in about an hour.

I've looked at all the easy stuff: terminals are clean, batteries are clean, connections are solid.

Are these batteries done? Anything I should do before I replace them?

Is it worth taking them somewhere to apply an equalization charge?


Seems like I should get more than a couple of years out of a well cared for bank.....

c

[Charlie]

Not to be a nitpicker but you said that you checked all the easy stuff. Have you run a hydrometer on the batteries? that is a good test even before connections. Next would be to see if there is an open connection somewhere.

[Curtis]

I have run a hydrometer on the cells...they are all about the same.

I'm fairly sure I don't have an open connection because it would show up on the Link Monitor.

[S/V Illusion]

They aren't that old and it sounds like you are doing everything "right". Your expectation that you should get more than a couple of years is quite reasonable - it's typical to get at least 5 years.

I'd definitely equalize them (the conventional wisdom is periodically do it anyway) to see what happens before replacement - lead is pretty expensive these days and you're liable to get "sticker shock" if you haven't already looked.

[Charlie]

Hi Curtis:

That is a huge run down on the batteries at a very fast rate. I also have a Link Monitor but don't know the technicalities of how they are run. (shows my ignorance) Would something be able to draw down the battery that was connected directly to the batteries. I have three things that are not connected thru the pannel 1) windlass, 2) Inverter and 3) Bilge Pumps. The first two are big draw items that could easily suck a battery down in an hour. The Bilge pumps would take a longer time. One test that I can think of would be to charge the batteries overnight. Then remove the battery cables. Test them in an hour and see if they have batteries have drained or not. If they have then there is likely a problem with the batteries but if the cells have all measured well with the hydrometer I would imagine that this is not the problem.

Please note I am not an expert and am just trying to give you ideas. There are other more knowlledgable people here and hopefully they will step in.

[Curtis]

Originally Posted by S/V Illusion

They aren't that old and it sounds like you are doing everything "right". Your expectation that you should get more than a couple of years is quite reasonable - it's typical to get at least 5 years.

I'd definitely equalize them (the conventional wisdom is periodically do it anyway) to see what happens before replacement - lead is pretty expensive these days and you're liable to get "sticker shock" if you haven't already looked.

How do folks equalize them that don't have a charger with that setting? Is this something that battery shops will do?

c

[witzgall]

Buy an Iota charger with the IQ4 smart module. It will do great things to your batteries - It charges not with a constant voltage, but pulses, which can help to being back "Lost" capacity. Something like that. I have the 45 amp model, it works great (but only one bank at a time- not multi bank)

Chris

You should always have a charger with equalization capability with wet cells.

Originally Posted by Curtis

How do folks equalize them that don't have a charger with that setting? Is this something that battery shops will do?

c

[The Mons]

As I discovered on a recent multiday cruise when both my engine and my battery charger went out, you need to have a backup battery charger.

My solution was to get a portable West Marine battery charger as the backup. The 30 amp model has the equalization feature. In your case, this would provide the equalization that you need without having to buy a new fixed charger. We use this charger all the time on other boats and at home.

[camaraderie]

Curtis...call your local battery or auto parts shop and ask about it. Alternative to a standard EQ charge would be to put it on an automotive (one stage) charger with the caps off and keep charging till you get bubbling...then go another 5 hours or so.
Start with a FULLY charged battery if you do this. Do this somewhere well ventilated and put papers under the battery as it will be bubbling acid.
Rather than spend 180 bucks for a West Marine 30amp portable charge...I suggest the Iota 55ampIQ permanent charger to replace your existing one. This way you can both EQ your batteries to see if they will come back...AND take proper care of them and/or new ones...for the same amount of $$.

[Curtis]

Well, this is kind of interesting!

I started shopping for "equalizing" chargers and can't find one that puts out more than 14.7 volts (including the IOTA & West Marine units mentioned). The charger that I have does that. Trojan recommends 15.5 volts.

Has anyone found a charger that does that?

The battery shops just put it on their chargers and press the "equalize" button but THEIR chargers don't put out more than 14.7 v either.

[Curtis]

Also, I have a theory about how I got here.

Submitted for your approval:

1) the Promariner charger has an absorbtion cycle (14.7 v) that, I think, will only become active when the batteries drop below a threshold voltage;

2) At the dock, we never discharge the batteries below the threshold. Even after a trip, we motor in so the alternator will have returned the bank to 70-80% by the time we plug in;

3) Therefore, the charger is almost always in the "float" cycle, which is causing the sulphatation.

I'm going to turn off the charger, discharge the bank, then let the charger go through it's full cycle a couple of times and see what happens.

[S/V Illusion]

Don't know what the specs indicate but my Xantrex Trucharge 40+ charger equalizes (my 4 battery T125 bank) at over 15V.

[Roy M]

I love this. This is going to ignite another firestorm: Go to Batteries Plus, buy a Pulse-Tech desulfator. Install it. Watch the specific gravity rise over the following weeks as the battery begins to hold more charge. Eventually, out of boredom, forget you ever installed it, and wonder, afresh, how long it's been since you replaced the batteries. Remember, this technology has only been around about twenty or thirty years. My customers keep asking how long before their batteries will croak, because they forgot when they were installed. My last set only lasted 14 years. The current set still has only 10 years in the battery box. You won't find these in West Marine, for a good reason: consider the sales volume of batteries in the total scheme of things.

Now, for the usual barrage of outrage and disinformation.

[hellosailor]

"3) Therefore, the charger is almost always in the "float" cycle, which is causing the sulphatation."
I doubt that. Sulphation tends to be caused by letting the batteries sit without a full charge on them.

Since there are three batteries, the first thing I'd do is unbolt them, and try each one of them--one at a time--to see if the problem is uniform across all three, or just in one battery which is pulling them all down.

If the problem is uniform across all three, yes, you have a charging problem. If it is in just one battery, you have a failed battery and there's no immediate need to change the charging system.

Once you've figured out whether it is the system, or just one battery, at fault, you can dig into the options for fixing this.


Roy?
" My customers " How come the only guys who totally endorse these systems are the folks making and selling them? As I recall, the car magazines, a certain sailing publication, a whole mess of arguably less biased sources have tried the desulphators, and they've all said pretty much "they don't work".
Yes, pulsing can break down some sulphates, but once the plate material has fallen off and gone down into the bottom of the box--it doesn't go back up, no matter how well you break up the precipitates.

[Roy M]

Hellosailor, guess I'm really confused. Last time I learned this stuff, electrons come from the sulfate ions in that noxious brew called electrolyte (sulfuric acid in this case). Turning on the light switch pulls electrons off the available sulfate ion and the silly thing plates out on the lead plates. Charging a battery returns most of the electrons back to the sufate and it floats happily satisfied back into the electrolyte. That's what the specific gravity going up and down is all about. Letting batteries just sit will also pull electrons off available sulfates, causing them to plate out until getting recharged.. The problem is that not all sulfates are exactly equal in their need for the same voltage shoving that little electron back into the outer valence ring (sorry, couldn't resist the high school chemistry reference). A statisically small number stay on the plate with each charge/discharge cycle. Eventually, fewer sulfates are available and the batteries become sulfated by the obstinate sulfate ions.

Equalization occurs at a higher voltage than one normally gets from the voltage regulator, otherwise we boil off the water. It also heats up the plates, eventually warping them, sloughing off paste, and other nasty things. The other option is pulse technology, which works at a micro level, doesn't appear to damage the plates, brings the sulfates back into solution, and makes the batteries hold their charge longer after treatment. There are competing pulse chargers on the market these days. Either there are a lot more victims of scams, or the technology works.

As far as the car manufacturers, Mercedes Benz apparently mounts these things on their cars for transport to the States to avoid dead batteries, then sends them back home.

You're absolutely right about precipitating plate material. The lesson? Buy high quality batteries, and care for them, which includes, in my case, using desulfators. By the way, I don't actually sell these things, a local distributor does, I simply install them as part of my services. It's really a major job: I have to unscrew the wing nut on the terminal of the battery, place the appropriate positive and negative lug from the Pulse-Tech, then replace the wing nut. I also record the specific gravity of each cell on those batteries that have fill caps. A couple months later I check the density of the electrolyte once again and show it to the incredulous customer. Where did all those sufates come from? Must be the gingerbread crumbs I sprinkle in a counterclockwise fashion around the batteries.

Come on guys. lighten up. Don't condemn something you have absolutely no experience with. Try one on a battery you find at the dumpster. If the load tester shows it's not shorted, then fill it with water, leave the pulsetech for a couple months, give it an overnight trickle charge and put the load tester back on it. Even the most stubborn adherent to the status quo has to acknowledge that something strange is going on here, or, then again, maybe not. Some more folks are going to explore this and be happy. The rest will help stimulate the economy with lead futures.