12 volt coach batteries.

[Hfx_Cdn]

    Sorry to be late again, but this afternoon I had a few minutes to do so investigative work.  Tried the gen set, still just clicking sound of a dead battery, got a bit frustrated and started flicking a few nearby switches.  Flicked the coach kill switch a couple of times, and for some reason tried the generator again.  Like the old joke says, what's that funny noise, by George, it's the starter motor on the gen set.  tried it several times and it worked every time, so now don't know if the 4 1/2 days charging on the 110 hook up, or a switch problem.  At some point, I will try using the coach electric without being hooked to 110 power.

 

[Gary RV_Wizard]

Ed,
Glad to hear the genny starts, even if you don't know why!

 

[Just Lou]

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

John, damage will occur when the material disintegrates and separates from the plate grid.  Simply getting dry does nothing chemically or structurally to the plate material, therefore no damage.  If getting dry was itself a problem, then you could never ship a dry battery.  Even dry shipped batteries have had their plates aged and charged in an acid bath. (been there, done that)

Now, when the flaking does happen, damage is done and it is irreversible, but it manifests itself in degrees of degradation.  The area in question may be ruined, but the cell may still be functional (assuming no shorts between plates has occurred).

If you think you need to do further testing to prove something, knock yourself out.
 

 

[Gary RV_Wizard]

Many thanks, Lou & Mexray.  This has been very instructive - I always feel more confident if I know WHY & how something happens.

 

[John From Detroit]

Lou I think we are close enough

Let me phrase it this way.. If a battery is sitting there and the acid gets down to the point where 1/4 inch of the very top of the plates is exposed.....  How much damage is there likely to be?

 

[Just Lou]

Let me phrase it this way.. If a battery is sitting there and the acid gets down to the point where 1/4 inch of the very top of the plates is exposed.....  How much damage is there likely to be?

John, Your question cannot be answered without first making certain assumptions on SOC, elapsed time,  operating temperatures, etc...

Chances are the active material (the lead paste) is not even exposed yet at the 1/4 inch level.  Just the top edges of the plate grid might be exposed so the extent of damage would be nil.  (however, any oxidation/corrosion of the exposed area could not be considered a good thing as this contaminant remains in the battery chemistry forever.)

Assuming an actual 1/4 inch of the active material is exposed, (sitting) in a fully charged battery, even accepting the fact of oxidation, the damage would be extremely gradual and most likely reversed when water is added.

The problem is that this is not how we use our batteries.  That same 1/4 inch of material above the level of the electrolyte will not be charged or discharged (through the acid bath) during normal cycles.  This allows the wet and dry portions of the plates to heat and cool at different rates, possibly warping and cracking the paste and damaging the battery with the flaked off material.  This heat can also damage the separators depending on what material was used in their construction.  Assuming no shorts were caused, adding water will stop any further damage.  You'll have a tough time proving or measuring any degradation.

(Insert disclaimers here................)

That's the "John in Detroit" answer.

The quick answer is:

Add 1/4 inch distilled water and   FAGIDABOUTIT ;D ;D 

 

[John Canfield]

This has been a dandy treatise about batteries - we might need some of it in the library!

 

[Tom]

This has been a dandy treatise about batteries - we might need some of it in the library!

I was thinking the same John. Just waiting for the last morsels of info to appear.

 

[John From Detroit]

Lou, thank you..  Though you phrased you answer very much as I might have under reversed coditions

That was just about exactly what I was looking for... I do agree at 1/4 inch of plate exposed the humidity in the chamber will be 100% and the plates will not dry out and damage, if any won't be worth talking about

At perhaps 1/4 of the plate exposed.. Damage will be a happening thing

In between... Well, I'm not going to test that .. Or worry about it.

 

[29er]

Heres's the other shoe.  Plates need to be covered with distilled water about every 45 days when pluged into AC power.  The generator (at Quartsite) lowered the water level below the plates (not by much) as I discovered after arriving home and doing routine maintenance.  They were covered when we left home. Now what?

Kerry

MH now at Las Vegas RV and they are clueless. Could be this or could be that....I had forgotten how bad their service is. However, carefree batteries may be the answer. 

 

[Ron]

Sounds like you may be overcharging the batteries.  I check our batteries every 6 months and have never found the water below the plates.

 

[Just Lou]

29er, There are two reasons for loss of water from a deep cycle storage battery.  The most common is overcharging and the second one is heat.  One is usually accompanied by, or is a product or component of the other.

The first case you described (batteries needing water approx. every 45 days) sounds to me like you have a converter charger that does not lower the float voltage, and resultant current, when your batteries are fully charged.  This is very common in older RVs (like mine) with one or two stage chargers. 

This overcharge will cause gassing which speeds evaporation of the water from the electrolyte.  We refer to this as boiling the battery.

Can you tell us the type and model number of your converter?  There are folks here who can tell you if it is one of the better, or not-so-good, ones.  And whether they think it could be contributing to your problem.

I'm going to guess that it was not entirely the result of running on your generator that caused the water loss on your trip to Quartzite, but charging from your alternator (at about 14.1 volts) while driving also.  About all that can be done to reduce this effect is to use the coach headlights and additional 12v appliances while driving, if the full alternator output is not needed.

Now, with all that said, certain conditions of your batteries can contribute to the water loss problems.

If your batteries are sufficiently sulphated heat can easily build up during charging.  It's possible that a couple of desulphating and equalization cycles might rejuvinate the cells to eliminate the condition.

Another likely condition is electrolyte contamination.  This is usually the result of NOT using distilled water for your water replacement.  Any foreign particles that can react with the acid or have metallic properties will cause heat build up when charging and a great loss in capacity when discharging.

If anyone has ever added acid to try to rejuvenate your batteries they have destroyed the balance of acid to water (the specific gravity) of the liquid and the battery will gas (boil) at a much earlier stage of charge.

Summary:

I would make sure my converter/charger was a good three stage charger.

I would have my batteries load tested and/or serviced if they are deemed salvageable.  If not, replaced.

My opinion is that you don't need to go to a "carefree" battery (read AGM ?) as you would probably just be masking the problem and would be wasting even more hard earned bucks.

 

[John From Detroit]

I support the wrong/bad/failed converter theory

With the converter Damon blessed me with.. I need to add water not every 45 days, not every 45 weeks but about every Mother's Day (OR whenver I start the camping season)  Checking is regular maintenance,  Adding water is "De-Winterizing" maintenance.

So far, at least 

 

[SCVJeff]

Kerry: Is that a Dimensions charger/ inverter?

 

[29er]

I don't know what brand the converter is; It the standard Tour/Vectra model from Winnebago.  I'll post as soon as Las Vegas RV returns the coach.
The one year warranty expires next week so I had to get the problem in writing (taking it to LV RV) to hammer the issue out with Winnebago.

Thanks, Kerry

 

[John Canfield]

I don't know what brand the converter is; It the standard Tour/Vectra model from Winnebago. ...

The one year warranty expires next week so I had to get the problem in writing (taking it to LV RV) to hammer the issue out with Winnebago.

Then it's a Dimensions charger/inverter.  Winnebago is pretty good about honoring problems discovered, but not repaired within the warranty period.  You might even have been able to email/call the factory to get the issues documented.

 

[29er]

Thanks John.  I'll pick up the coach tomorrow, then next week see what Winnebago says about this problem. You reinforced my thoughts of putting it in the shop to get everything documented.

Thanks, Kerry

 

[SCVJeff]

When you get it back there is a 4-position switch on the inverter itself that selects various charge rates and battery types. For your setup it should be in position 'C' or 'D'. Position 'D' is for battery stacks less than 400A, 'C' for stacks larger. Even though I swapped to 4ea. 6V, I left it in 'D' just because.

According to the folks at the factory, the only difference between the two is a timer that changes it's max charge time (A & B deal with sealed batteries the same way). I don't really get the purpose other than a safety since it's a 3 stage smart charger with temp sense, so one wouldn't think this would make a difference.

 

[29er]

Thanks everybody.  Got the coach back last night and read the owners manual. Sometimes it takes a while for genius to occur.

The batteries are NAPA 8231.  Went to the NAPA website and discovered they (8231) are MEDIUM cycle batteries that requires a SLOW rate of (re)charge.

Problem solved! They gotta go. Incidentally Las Vegas RV said they were "toast".

I'm amazed Winnebago went on the "cheap"  Shame on them....and me too.

Kerry

I'm startled at the price of both type of sealed batteries.

 

[Gary RV_Wizard]

I'm amazed Winnebago went on the "cheap"

And why would that amaze you?  Such design decisions, even seemingly irrational ones, are a way of life in the RV industry  On the other hand, if everybody used only "best of breed" components and materials, every RV would be $1M+

I have a similar story - my 04 American Tradition came with 4 Group 27 AGMs, perhaps leading you to believe American Coach lived up to their top end reputation. But they "cheaped out" too - they were only 76 amp-hour batteries, giving me a total battery bank of only 304 AH in a coach check full of electronics and gadgets that suck amps like crazy.  [For what it's worth, an engineer at AC told me the reason was weight savings rather than cost. In the previous model year they had come perilously close to exceeded the rear axle GAWR on some floor plans and had to go "on a diet".]  If you just drive from A to B and maybe make a few rest stops along the way, they are fine, but if you spend a night boondocking you will be running the generator by 9 pm.  Two of them failed after only 3 years anyway, so I have replaced them with Group 31 Trojan AGMs @ 105AH each. And yes, my coach still is under its rear axle GAWR, though barely.

Realistically, many RVers hardly know they have batteries and could care less. They would much rather have a 2" larger tv than a better quality battery.