Monday, July 22, 2013

Mr. Fixit Likes To Complain


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All Done


If these continual repair reports begin to seem tedious to you, let me just say I know what you mean.  After I got my generator working properly a few days ago, I went off and left it running for as much as 8 hours at a time with a 20A charger working the batteries.  And every morning I am back down to 12.3 Volts.  Bah.

With the batteries disconnected, my converter wouldn’t even power one light for long.  It was obvious toast.  So I ordered a Progressive Dynamics PD 4645 replacement sent from Amazon to a friend staying in a commercial campground in Salida.  It arrived Wednesday, so I went down Thursday, paid $30 to check into a gravel slot for a day, and installed it in a couple of hours.  Then I plugged in for the rest of my 24 hour sentence.

Problem solved?


Not exactly.  The converter seems to work fine.  But everything is not quite right, and it took the intervention of Mr. Internet to point me in what I hope is the right direction.  I probably won’t know for sure for a week or so yet.

The PD 4645 is a 45 Amp “4 Stage Charger” designed to slide right into the cabinet installations of converters preferred as OEM by many cheap bastards …er… manufacturers.  Instructions are simple, and detailed.  Stage 1 is the Boost charge, at 14.4V.  Stage 2 steps it down to "Normal" or 13.6V for the last 20 % or so.  Stage 3 is a "Storage" voltage of 13.2V, for keeping the batteries topped off when charging is complete. 

Stage 1 is the workhorse.  I have seldom seen Stage 3.  And Stage 4 is a real ghost in the machine.

“Stage 4” is described as a “Desulfation” routine that supposedly runs automagically for 15 minutes every 24 hours.  What?  That would be fine if I were always and constantly hooked up to a wall wart, and had brand new batteries to begin with.  But then why would I need batteries? 

What I tend to have instead are 2 hours here, 3 hours there, with days between, and maybe a year’s malpractice behind me in trusting an old converter probably made by the People’s Liberation Army, which may not ever have fully charged my batteries in the first place.

Now I admit I’m a rabid fan of Pandora, mornings and evenings.  And I recharge my laptop and other small toys daily.  And there’s a lot more of those than there used to be.  So maybe I’m using a bit more power than I used to.  And I only have two batteries instead of the four I once had.  But I still think I ought to be getting more joy than I’ve been getting lately.

Mr. Internet to the rescue!  He told me avidly about a special routine of charging at 14.4 Volts for 4 hours that would cook the sulfate scale off the lead plates….

Okay, okay.  Have mercy.  A little background.  Here’s what I think I know about lead/acid battery chemistry.  Fear not, this won’t take long.  Everyone knows that electricity is released when sulfuric acid in the presence of lead breaks down into lead sulfate and water, right?  In the process, the lead sulfate is laid down thinly on the lead plates of your battery.  Now ordinarily this doesn’t matter, because in a little while you are going to hook it up to a charging source, like an alternator, that will drive the sulfate back off into the surrounding electrolyte and form sulfuric acid again.  Right?  Well, what if for some reason, like perhaps a vast Communist conspiracy, you do not fully recharge your battery?  Pretty soon that sulfate begins to layer up into a matrix somewhat like the scale in your water pipes at home.  And that part of your battery is then dead, dead, dead, because the acid can’t get to the lead.

This is what Mr. Internet tells me has happened to my batteries.  They have become sulfated.  All I know is they don’t last nearly as long as they used to.  First they were in my fifth wheel, briefly, and then in the Lazy Daze, where they worked fine.  Then in the XT-200, where…. well, I don’t know, because I never used the XT-200 for anything but therapy.  It just sat in the driveway.  And then they landed in this little Weekender, here in Colorado, where they haven’t been working worth squat.  So off another battery goes to recycling, or even possibly to the landfill to fulfill its secondary destiny of poisoning the water supply and retarding the next generation of Americans. 

Except…there is a rumor of a way to revive the battery.  If I am lucky, and the process hasn’t gone on too long.  And that is through this process of “desulfation”, which is accomplished by pumping in lots and lots of extremely attractive electrons to tempt some of that sulfur to go play in the water again, and make lots of little sulfuric acid molecules like God intended. 

Forget tapering off.  Forget 15 minutes every 24 hours.  Pour it on.

Which brings me again to the embarrassing lack of details about the existence of this “desulfation stage” on the PD web page.  Or elsewhere.  Let alone how to use it.  Nothing in the customer instructions.  It’s all automatic, you see.  Don’t worry your pretty little head about it.  Why, if you got to tinkering around with the innards of your battery, it might boil over, or explode, or maybe the earth itself will crack open and swallow your whole rig down into a giant fissure of Hell.  And then burp.

Mr. Internet cracks me up.  He’s always on all sides of an issue.  He’s got it surrounded.  He is, in the words of Woody Allen, “polymorphously perverse”.  In fact, it may be that one really good reason for camping far from Mr. Internet is the same reason people take to drink.  It silences the more annoying parts of our brains. 

But parts is parts, and sometimes we need them all.

One thing finally did get through to me:  “14.4V?  Heck, it does that already, in the Boost Stage.”  Then I was reminded of the built-in “Charge Wizard”, which is a button that lets you set each stage manually, even at times when the automatic process doesn’t want you to.  What if… What if the “Desulfation Stage” actually isn’t a matter of What, but of When? 

And that’s it.  A matter of timing.  As with so many things.

Reading voltage is useful to tell you how low your battery is, but it doesn’t tell anything about how full it is.  When the PD senses that your battery voltage is around 12.7V, it starts to lower the input, to “taper off”.  At that point, you just stick a fat finger on that button and make it stay in Boost Mode.  Got it?  One click.  Gas bubbling off?  Good.  That’s what you want.

Last night I did this for a couple of hours.  Then today for 4 hours, which I learned is a self-imposed manual operation limit, after which it turns itself off.  Unless you reset it.  That means I can go off and leave it, at least with the big batteries I have, and it will handily prevent any Battery Apocalypse without further input from me.  Which is just as well. 

You can do the same thing with a “dumb” charger that puts out 10 Amps or more, but you have to watch it.  Eventually- someday, maybe- it might boil away the electrolyte.  Mr. Internet says 4 hours at a time should be okay.

Why don’t they spell all this out in the instructions?  I think it’s because of lawyers.  Here’s what they Do say:  “The manual button has been provided to allow the operator to temporarily override the converter (not recommended) or to verify the converter is operating properly.”

Thanks.  Not a word about manual desulfation.  Not a word about saving your old batteries.  Just “Push this button at your peril”. 

And then go buy new batteries.  You deserve them.


6 comments:

Shadowmoss said...

So did it work?

Bob Giddings said...

The simple questions are the hardest to answer. I don't have the right equipment to know the amps my batteries are prepared to deliver. For that I'd need a shunt and ammeter. And Xantrex's linklite, for instance, costs as much as two new batteries. Even the good Trojans. I'd rather have the new batteries.

Subjectively I'll know something in a couple of weeks anyway. I'll simply monitor my Voltage every morning. Voltage, as I said above, doesn't tell you much, but it will tell you when your batteries are weak. Lately they've been at 12.3V or below after a day of use. Assuming my use doesn't change much on average, then any reading above that in the morning means success.

One good sign is that a hydrometer test finally got into the green after the first two desulfation sessions. Not much, but an improvement. I'm going to try a couple more in the next week.

I won't be able to quantify it without the proper tool. But the only time the actual number matters is if you suspect battery failure. In that case, the solution is buying new batteries. The number won't change anything. When the tool to identify failure costs more than the ultimate solution, it is hard to justify buying the tool.

I believe I have now done all I can do about this except cut back on use or buy more batteries. I am unlikely to cut back much on use.

I would carry more batteries if I weren't already overloaded. It doesn't take much more time to bulk charge 4 batteries than it does 2. The generator just revs up a bit.

Barney (The Old Fat Man) said...

Bob, On your way back to warm weather this fall stop in Del Rio Tx at http://www.arcrite.com/ and get an axle that is strong enough installed under your trailer. They are a full manufacturing facility that can handle any running gear or frame improvement you need. San Pedro campground for $2 a night is a couple of miles up the road.

Bob Giddings said...
This comment has been removed by the author.
Bob Giddings said...

Thanks, Barney. There's a good place in Georgetown, too. I told him I'm about 700 lb. over, and he told me to invest in some heavy duty wheels and tires. He said the axle would be okay. I took him at his word, since he was talking himself out of a job.

Sandra Pover said...

Hi Bob,
I'm happy to see you back on the road and more importantly, writing about it. You have a wonderful gift with words.
I plan on heading down to the South Rio Grande Valley with the LD this winter via New Orleans... finally took the plunge and retired!
Take care of yourself and maybe we'll bump into each other on the road sometime.
Ginger