12 volt coach batteries.

I would have a pair of AGM's if I had done my research on batteries in the proper sequence.  I installed an additional pair of 6V wet cell batteries three years ago, when I first got my coach, and have spent the difference in cost in building a custom vented battery box to accommodate them.

You fellows are correct about the 'ease of maintenance' regarding AGM sealed type batteries...sure wish I had more dedicated AGM customers like you, in my area! ;D

I have a collection of batteies.. Each does different things

The main "house" battereies are 1: OEM and 2: Interstate U-2200's  Under the steps they are easy to get at and medium to water  I'm not all that thrilled with Interstate's "Quick Cap" however.

The inverter has a lovely pair of AGM's there is a ventelation issue (There is ventelation, power vent no less(Brushless fan) but it's still less than I'd need with flooded wet cells) that work with the inverter  This system is normally independent from the house but can be tied together by switches,, Either full tie in or "one diode down"  That way the inverter can charge the house if the PD-9180 eer fails, or the house can supplement the inverter or the alternator can charge the inverter.

Engine battery is maintenance free


So I kind of test 'em all

I'm not all that thrilled with Interstate's "Quick Cap" however

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Care to elaborate on that John? I liked the ones I had on my prior coach house batteries.

ON my coach those removal of those triple caps takes  a bit of skill due to cables and such in the neighborhood (Hold downs are included in teh "such")

Single caps woudl be easier to wrangle.  That's all

I do like single caps

Hey 29er - this is your thread... What say?  Are we done?

John Canfield said:

Hey 29er - this is your thread... What say?  Are we done?

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Since when does anyone "own" a thread?

Hi Lou - the intent is to pass useful information to the OP and it seems to me he has had about all of the useful information we can stand in this particular thread.  Don't know about you, but it is always more fun to me when the OP is providing feedback as the thread evolves.

    Sorry to jump in so late, but looks like I'm one of those who should have know better and maintained my coach batteries.  The 2 coach batteries were replaced about 3 yars ago, I went to start the generator for its monthly run, and all I got was clicks, even when I flipped the emergency start switch.  I went out and looked, first time to have done so, at the batteries and they were almost dry.  I've added almost 3 quarts of distilled water to the 2 of them about 3 days ago, but I'd say they are fried as they still wont start the generator.  Looks like I'm in the market for new batteries.  Is there an easy way to check if they are the problem? is it as simple as disconnecting them from the system and running a volt metre across them?

John, I agree.  Thread drift and side bars continue long after the op gets and answer (often in stead of)

I guess I was trying to determine if you (or yours) claimed exclusive rights to threads in the Winnebago forum.

I was more than a little offended yesterday when you jumped in the middle of a thread where I was attempting to help a gentleman, and without acknowledging me, him or the subject, simply told him to have patience and maybe a winni owner would show up to help eventually.

I assumed I had violated an unwritten rule about infringing on Winnebago territory.  It won't happen again.

Hfx_Cdn said:

    Sorry to jump in so late, but looks like I'm one of those who should have know better and maintained my coach batteries.  The 2 coach batteries were replaced about 3 yars ago, I went to start the generator for its monthly run, and all I got was clicks, even when I flipped the emergency start switch.  I went out and looked, first time to have done so, at the batteries and they were almost dry.  I've added almost 3 quarts of distilled water to the 2 of them about 3 days ago, but I'd say they are fried as they still wont start the generator.  Looks like I'm in the market for new batteries.  Is there an easy way to check if they are the problem? is it as simple as disconnecting them from the system and running a volt metre across them?

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It is my understanding that once the plates are uncovered, that uncovered area is permanently useless and will never participate in the chemical reaction. 

Lou (onaquest) said:

I was more than a little offended yesterday when you jumped in the middle of a thread where I was attempting to help a gentleman, and without acknowledging me, him or the subject, simply told him to have patience and maybe a winni owner would show up to help eventually.

I assumed I had violated an unwritten rule about infringing on Winnebago territory.  It won't happen again.

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Lou - you are always welcome to jump in here about anything if you have something to contribute.  There are some unique and model-specific problems and situations that are best answered by somebody with that specific experience,  but even so, a general comment might bring out some interesting and thought-provoking points.  Sorry to have offended you 

John Canfield said:

It is my understanding that once the plates are uncovered, that uncovered area is permanently useless and will never participate in the chemical reaction. 

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I'm not convinced of that, and in fact did some work back in college that suggests otherwise, however that was with a DIFFERENT type of battery.  Thus all I can do is question.

However I'm not willing to test the theory. That would require $$$ and just now.. That's not in my wallet.

Uncovering the plates does indeed do them harm, but they are not completely useless just because it happened once.  However it may be more or less true in Ed's case, since it appears they may have sat exposed to the air for a long time.

I've added almost 3 quarts of distilled water to the 2 of them about 3 days ago, but I'd say they are fried as they still wont start the generator.

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Are you on shore power and have they been charging since you added the water?  Do your other 12v appliances/lights work? They should be getting juice form the converter, but you might try shutting shore power off and see if anything 12v works without the converter running. Or just unplug the converter, if that is an option on your coach.

Something seems awry here, since your aux start switch is not functioning either. If it was, the chassis batteries would provide genny start power when the aux switch is held down.  However the aux relay itself is 12v powered, so sometimes that means the house batteries are so bad they can't even make the relay function.

The only thing that would make the exposed portion of the battery plates unusable would be (and it does happen if left long enough) is for the paste in the plate grids to dry out and flake off.  The particles then fall to the bottom and can mound up high enough to partially short out the cell or simply decrease the battery efficiency by their absence.

The plates of a battery actually start out in life as identical twins.  They are simply lead grids (honey combs) with antimony added for rigidity.  The positive plate/grid (honey combs) get filled with lead peroxide paste, called red lead, and the negative plate is pasted with a nearly pure lead paste. 

The plates are interleaved (much like your fingers when clasping your hands together) within a cell.  The plates are held apart by a porous separator material of choice.  Back in the fifties we actually used wood.  The cells are then connected together to form a battery.  Add electrolyte of water and sulfuric acid with a specific gravity of about 1.28 and you have an instantly charged battery.

My first job out of high school was in a Gould National Battery factory.  I've done every job in battery manufa assembly except paste the plates.  That was a clean room job.  My union classification didn't allow me in there.

Just an FYI note:  In a fully discharged battery, the composition of the positive and negative plates is identical (lead sulphate)
and the electrolyte is pure water.  When fully charged the pos plate returns to lead peroxide, the neg to lead and the electrolyte to approx. 30% acid and 70% water. 

NEVER add acid to a discharged battery just because the solution seems to be pure water.  The acid held in the plates will return to the mixture, when charged, and you will have a very corrosive boat anchor on your hands.

Interesting points Lou...

I believe the flaking of the plates will eventually happen even with the plates always covered - I have had batteries act fine one day and not the next.  This is another advantage of AGM or gels - the plates can't short out like wet batteries.

John Canfield said:

I believe the flaking of the plates will eventually happen even with the plates always covered - I have had batteries act fine one day and not the next.  This is another advantage of AGM or gels - the plates can't short out like wet batteries.

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Exactly, John.  It's the normal aging process of even a well maintained wet cell battery.  The vibration and jolting of the vehicle just hastens it along.  The same battery, in a stationary installation, properly maintained and not abused with multiple deep discharges should last almost indefinitely.

Whew!, almost indefinitely?  I really pinned myself down with that one ;D ;D

29er said:

My question is: can the batteries be converted to four 6v deep cycle as currently factory configured?  I'm referring to the charging, etc., systems.

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Kerry,

Let's recap a bit here...

1. Sure, you can convert your (3) 12 volt batt's to the (4) 6 volt batt's.. assuming you have the room to mount them - they are wider and higher than your original batt's, plus you're adding one more battery, which I assume you're aware of.

2. about your charging system...if your existing converter/charger is running in the 'bulk charge' mode most of the time now, you need to find out why - maybe it doesn't have a very big charging capacity (what is the charging AMP capacity?).  Changing to a larger battery back with more Amp Hr capacity will only adding more 'bulk' charging time.

3. many RV'ers believe they can recharge their battery banks in a few hours, after running the batteries down for many hours...It's all about the AMP HOURS...look at your battery bank as an 'electron tank' that has a capacity equal to the total battery bank's Amp Hours...

Say your existing (3) batteries have a total of 300 Amp Hrs...if you discharge that bank down to about 10% charged, you'll have to 'pump' about 270 Amp Hrs back into your batteries to have them fully charged...If your charger is rated at 30 Amps, that means one hour of running will recoup only 30 Amp Hrs back into your battery bank!... Therefore, dividing 270 AH by 30 A, if everything were running 100% efficiently, you'll have to charge for 9 hours to be fully charged...

This 'charging' scenario above doesn't take into account any losses in your wiring, extended running time in 'finishing' mode of your charger, and of course these systems are far from '100%' efficient...which would make me tend to advise an additional 30% to your charging time for a 'true' fully charged batter bank, or a total of about 12 hours in the example above....these numbers would be different, of course if your charger is of higher capacity, say 50 Amps, which would take about 7 hours...

There is just NO FREE LUNCH when it come to recharging your batteries - what ever you remove, you'll have to replace to get back to a fully charged condition, and until one run's the 'numbers', it can be an eye opener!

If you aren't able to recharge your battery bank fully between uses, you will be fighting a losing battle...when boon-docking it's imperative to maintain a battery charging routine that will assure you'll be able to get the full use of your batteries during the next usage 'cycle'...

To get back to your question....you have to ask yourself if, when adding additional Amp Hours (more batteries) to your battery bank, can you recharge them between uses with your existing charging equipment?  Or do you need a larger Amperage Capacity charger?  Or can you put up with longer generator running times with your existing charging capacity?  You didn't note these particular numbers, IE, Charger Amps, Battery AH capacity, etc., so it's difficult for us to predict, per your original request...but you can use your own numbers as I've shown above to get a useable estimate...

Good luck out there...

RV Roamer said:

Uncovering the plates does indeed do them harm, but they are not completely useless just because it happened once.  However it may be more or less true in Ed's case, since it appears they may have sat exposed to the air for a long time.

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That it harms them I've no doubt.. What I question is if it ruins them or not.

And as I said.. I've not tested it so it remains a question, not a Challenge

I'd love to know for sure just how much damage it does. 

I'd also like to know if the damage is reversable and if, for example, letting the fluid level get say 1/4" below the top of the plate means that quarter inch is toast. or if that is basically harmless

NOW.. boiling them dry... That is a very bad idea

John,

Battery grids/plates need to remain immersed in the electrolyte solution to avoid corrosion/oxidation. 

Prolonged expose to air will cause the bond between the grid and the active material in the plates to crumble away...this dislodged material may abrade the plate separator material to the point it wears through, causing then two adjoining plates to touch, effectively causing a 'short' in that cell, ruining the battery...Also, this dislodged material may fall to the bottom of the battery case, building up to a point where it may touch two adjoining plates, etc.

Short periods of time with the plate tops uncovered won't likely alter a battery's service life, provided additional distilled water is added and the battery is recharged to blend the water with the existing electrolyte.

If the electrolyte level is allowed to become lower due to not checking the battery, the corrosion will become greater and irreparable damage may occur.  If your battery requires large quantities of water, and after recharging, you see that the electrolyte has become a 'gray' or a cloudy color, the battery is probably no longer serviceable - time to replace!  The electrolyte should remain 'clear', if 'cloudy gray', it's got particles of corroded plate material in solution, and will not have it's original capacity, leading to premature failure.

We battery guys always know the battery's been run low on electrolyte when we see the dark color of the solution...this is not a 'warranty' covered condition, and causes some misunderstandings with customers when we try to explain that this is a 'maintenance' issue, and not a manufacturing defect...

My suggestion would be to replace the water, charge the battery, let it rest for a couple of days, and see it it's still charged...a load test will determine if any damage has been done...and if the battery is still usable.