Newbie question on battery installation

[terryl]

Hi! I'm a newbie to RV ownership. I purchased a 2004 Fleetwood Fiesta 32S about 6 weeks ago. While learning all the ins and outs, I found this site to be an invaluable source of information. Thanks to all who contribute to it. On my maiden voyage dry camping trip, I found that the two Optima Blue Top 34M house batteries would not hold a charge for more than a few minutes, even after being plugged into shore power for 4 days before the trip. I tested them with a voltmeter when I returned home, and verified that these 2 year old batteries were discharged. I have been reading the various opinions on this and other sites regarding the benefits of two 6-volt batteries connected in series vs. two 12-volt ones in parallel. When I went to remove the two Optima's today, I found that they were connected in series rather than parallel. My knowledge of vehicle electrical systems is marginal at best. Is it possible that this RV could have been operated for the past 2 years hooked up like this? Could this be the reason these Blue Tops won't hold a charge? I know they're not the correct battery for this rig, but if I can salvage some time out of them, I would rather not use two $190.00 batteries as $8.00 cores on a new purchase. Right now I have one of the two on a trickle charger in the garage. Am I wasting my time? Thanks!!

[pcurt23]

Not sure if your current batteries are toast or not but, two 6volt batteries connected correctly do provide more amp hours than two 12v batteries. You should be able to get the batteries tested to see if they are still good. You should also have some sort of 3 stage battery charger in your rig like a charge wizard. You may already have one.

[KIX]

I live near jacksonville, fl and the Optima disstributor is Interstate Batteries. They will charge your Optimas correctly ( a trickle charger is NOT correct) then test them all at no charge. The post above mentioned that you need a 3 stage charger and he is correct.
As to the Optimas powering the coach when wired in series.......that would supply 24 volts to the coach 12 volt system........If this was the case then you probably have more problems.
I don't think Optimas wired in series is a problem to the batteries but when connected to a 12 volt battery charger .......that would be a problem as you would essentially be trying to charge a 24 volt battery with a 12 volt charger.

["007"]

Welcome terryl to irv2.
What you need is the 12Volt side of life which explains your RV electric systems.
You also need a good 12V battery charger to get your batteries up to full charge any other way will take to long.
If after charging for a day or so and they still do not hold a charge one of or both batteries are toast and will need to be replaced.
Recharge new batteries with a battery charger.

[BryanL]

re: "two 6volt batteries connected correctly do provide more amp hours than two 12v batteries." -- at 6v maybe. but most are interested in energy capacity at house voltage, not usually 6v amp hours.

Lead acid batteries, 6v or 12v, have about 12 usable watt hours per pound of available energy. Expect about a 4-7 year life for wet cell batteries and maybe 5 - 8 for AGM's if they are properly cared for. (re NAWS FAQ)

There are no inherent benefits to 6v or 12v batteries as far as capacity or life.

Always only use measures that the manufacturer or retailer will put his money on like specifications, cost, or warranty. Anytime anyone starts spouting off about 6v or some particular brand or 'deep cycle' or whatnot, put on your skeptics hat and seek out good objective measure that someone will put their money on.

If the 2 optimas were wired in series, they would be appropriate for a 24 v system. If it is a 12v system, that means that they were never properly charged. It is indeed possible that the batteries could have been operating at half voltage if they were always in line with your converter.

What you describe sounds like someone took off on advice they got on forums like these. They heard that AGM batteries like the Optima were the greatest thing since sliced bread. That was probably after they heard all the 'true deep cycle 6v golf cart' Trojan battery braggadocio. The problem is that when they found the 6v'ers didn't provide a magic bullet, they put in the new magic bullet attempt without realizing they had to rewire the bank. -- a good example of why you need to watch out for the testimonies you can find in these discussions.

First, make sure you know if you are running a 24v DC system or 12v DC system. Then find batteries from a retailer who sells a lot to folks like you and will stand behind what he sells. Make sure the batteries will fit in the compartment and can be wired for the proper voltage.

Then keep in mind that often one of the best things you can do is to upgrade the RV converter to one that has intelligent multiple stage charge and a battery storage mode that will assure a full charge and provide a technique to inhibit battery sulfation while in storage.

[pcurt23]

Here is a lot of battery information. Batteries -- and Other Electric Stuff by phred

What you find around the campfire are many different twists on the same topic. This information seems to suggest that if you have a choice or are starting from scratch 6v is the way to go. I have had both 12v (4 group 27) and 6v (4 210 AH) setups and the 6v system provides power for several hours longer. The batteries themselves are in their 4th year. I replaced the 12v batteries after 3 years.

pcurt.

[Paul R. Haller]

Try taking out the Optimas and hooking them up to a good stand alone battery charger. Charge them for 2-3 days. After unhooking the charger and allowing the optimas to rest for about 2-4 hours take a voltage reading. If at 12.8 volts... that's a full charge for a 12 volt battery. Now, take it to auto zone for a load test. If it's not at 12.8 volts or so after resting a while it's probably toast and will never accept a full charge. I also am quite concerned about the health of your 12 volt system in the trailer. If, at some point, 24 volts were hooked up to the converter, it may fry the output fuses on the converter. Check it plugged into shore power and it should read about 13.8 volts or higher. If not, check your converter fuses. It may have even fried your converter output. Check to see, after getting the model # off your converter, if it's equipped with a 3 or 4 stage charger. My guess it's not. You might want to consider buying a 4 stage converter from Progressive Dynamics, Iota, or others. I have had good luck with both brands. They are often on line for less then an RV outlet. I think I bought a 90 amp PG for $170 off ebay brand new last year. It will save you $ in the long run by saving your batteries.
I hope you can salvage your Optimas.
-Paul R. Haller-

[Paul R. Haller]

I forgot to include the state of your battery cables. Most RV shops use no bigger then a #6 wire for battery interconnect wire. That's inadequate to hook up batteries. I use a 4/0 cable available at welding supply shops and crimped on heavy duty copper lugs also available at welding centers. You want to use every amp hour out of your battery bank. Why limits its performance with a #6 or even a #2 wire? Have no voltage losses anywhere by upgrading to 4/0 wire.
-Paul R. Haller-

[BryanL]

re: "... many different twists on the same topic. ... 6v is the way to go. ... the 6v system provides power for several hours longer."

When you replace aged batteries with new ones, you may notice an improvement in capacity. When you replace smaller batteries with bigger ones, you may also note an improvement in capacity. This only means that newer and larger batteries will have a bit more capacity than older, smaller ones. It does not mean the newer ones are any better otherwise.

If you check the actual numbers, 6v batteries do not give you any more of either capacity or life compared to equivalent 12v. I do not think it good practice to promote things as better without good measure to support it - and that means statistically valid with appropriate consideration for context, accuracy, and precision.

It is also worthwhile to note that factors such as age, temperature, use profile, and cycle to cycle differences can each influence available battery energy by more than 10%. Also be aware that the end of life for most lead acid batteries is not well defined. Lab tests put this at the 20% of capacity drop from new. Many Rvers will use batteries happily well past this point.

Paul's point about wiring is also a good consideration. The thing to keep in mind, though, is that wire is sized for expected current loads. If you run a 2 kw inverter, then 00 and bigger wire may be called for. The wire at the local auto parts store for starters and such things is usually 2 gauge and that is telling you something. Most RV circuits are 20 amps over fairly short runs so 8 or even 10 gauge will do. There are calculators on the I'net that you can use to calculate wire losses to give you an idea of just what you might gain by using larger wire.

Paul also had some good advice on system checks and what to do to see if the Optimas could be recovered.

The reason for "many different twists" is that many do not go by objective measures appropriately considered. There is a lot of bad or even incorrect advice from some folks who are supposed authorities and should know better. You need to look for reasons why, remain skeptical, and be able to trace it back to appropriate measure in order to make good decisions.

[terryl]

Thanks to everyone for their input, suggestions, and links to additional battery information. I've learned more about batteries in the past day than I ever knew previously! I had already put one of the Optimas on a 2 amp trickle charge over night, and this morning it was up to 12.4. Taking the advice of one of the posters, I took both batteries down to an Optima dealer so they can correctly charge and evaluate both of them. They are both marine cranking Blue Tops, not deep-cycle so I know they are the wrong selection for RV house batteries, but if I can get a few months use out of them, or use them in an automotive application, I might as well try. In the meantime, I shopped both 12 Volt Interstate Marine/RV deep cycle ($63) and 6 Volt golf cart ($80) batteries at Costco today. Still undecided which way to go on this, as there are strong opinions on both sides.

I did confirm that my rig has a WFCO 8000 series converter/charger in it, which moves between normal, quick charge and storage modes, depending on output voltage, according to the manual. I have to assume it is (was) working, as I noticed the fan was running on it when I was plugged into shore power a few weeks ago.

Whie digging through the many manuals that came with this RV, I again reviewed a "typical electrical diagram" in the Fleetwood Owner's Manual. It clearly depicts a battery cable running between the negative terminal of house battery #1 and the positive terminal in house battery #2. In the diagram, the negative cable in house battery #2 runs to the negative side of the chassis battery. In my case, both the house battery and chassis battery were grounded separately. (Probably no difference). The manual also depicts the positive cable running from the house battery #1 to the bulkhead fuse block, and then back to the main chassis battery. It is also listed as a 12 volt system.

In this respect, I am no further ahead than yesterday, as everything I have read states that a parallel connection in a dual battery 12 volt house system should be positive to positive and negative to negative. According to the owner's manual, the way I found the batteries hooked up (- to +) is the way they should have been, but it defies the logical explanation that I have found in all battery-related threads.

Well, at least I have the weekend to figure this out, as Napa has my Optima blue tops!

[BryanL]

re: "They are both marine cranking Blue Tops, not deep-cycle so I know they are the wrong selection for RV house batteries" -- the only difference is likely to be warranteed use. The differences in the batteries themselves are small if you look at the numbers.

The criteria I keep trying to get across is to look for the measure - if you can find any measure for a battery that will distinguish between a "deep cycle battery", "RV/Marine battery" or even an SLI, please let me know. I haven't found one yet. From anything I have found, these are just marketing terms.

re: "Still undecided which way to go on this, as there are strong opinions on both sides." -- again, look at numbers the manufacturer and retailer will put their money behind. If there are strong opinions against this, I'd like to be able to better understand them - and I haven't seen any. The easiest numbers to get are cost, warranty, and energy capacity and they are usually sufficient.

re: "my rig has a WFCO" -- this should be an excellent charger and maintainer from what I have heard.

re: "According to the owner's manual, the way I found the batteries hooked up (- to +) is the way they should have been, but it defies the logical explanation that I have found in all battery-related threads." -- there may be a typo or some missed caveat in the manual or even some possible wiring mislabeling.

If you connect 2 batteries in parallel, the resulting voltage is the same as that of each battery. If you connect them in series, the voltage is the sum.

[Paul R. Haller]

BrianL is absolutely correct in that pound for pound there are no differences between 6 volt and 12 volt batteries. He is also correct that with all marketing hype aside there are little differences between lead acid batteries of any type. In my case I base decisions on which battery to buy on simply a cost basis. In my case the 6 volt golf cart batteries were 30% less then their 12 volt counterpart so, I used the 6 volt batteries.
In my explanation of cables in my trailer its helpful to point out that the 8 batteries feed a 3000 watt inverter. I know thats not your case but In my application its very easy to pull 200 amps through a conductor that feeds the inverter so, a large conductor is important. I am value minded... my wife just calls me cheap but I like getting the most out of my batteries and find that careful attention to their upkeep is in fact more important then in how they are used. In my RV, the batteries sit for many months at a time not being used so I put my money into maintaining them. Then occasionally I use them... hard. Then, they sit some more months before heavy use again. That means in actual practice its far more likely that I'll kill the batteries from not maintaining them while stored rather then the occasional heavy use. I add distilled water when needed and keep them fully charged and use a good converter that desulfates them occasionally too.

-Paul R. Haller-

[terryl]

Just a quick update for those who helped me with this issue. Someone on the Fleetwood 1-800 help line verified that this rig came with two 6 volt T-105 house batteries from the factory. That would explain the 2004 Fleetwood owner's manual showing the house batteries hooked up in series. It's too bad that the previous coach owner installed the two 12 volt blue top Optimas, but neglected to change things over to a parallel hookup. So far, no apparent damage, as the converter and all the 12 volt accessories seem to be working. Napa just comfirmed with me that the Optima's are toast and won't hold a charge. I believe I will go back to a 6 volt house battery system for no other reason than it came that way, and the battery trays and hold-down brackets are sized for the smaller 6 volt batteries, and won't fit over 24D series Interstate 12 volt ones. The Interstate golf cart batteries that would fit (from Costco) are called Grp GC2 and are rated at 100RC. Does anyone know if these are equivalent to T-105's?

On an unrelated note, the girl on the help line, after I gave her my Fleetwood FIN#, argued that my rig is a 2005, not a 2004. My title and owners manual both say it's an '04, the date of manufacture on the door state 05/04, and it was first registered in 05/04. I could see if it was manufactured in Oct. or Nov. calling it the next year's model, but calling a rig manufactured in May of '04 a 2005 seems to be quite a stretch. So, that piece of good news was short lived, once I checked the rest of my documentation.

Thanks again to everyone for their input.

Terry

[KIX]

Quote:

Originally Posted by terryl Napa just comfirmed with me that the Optima's are toast and won't hold a charge. Terry

Terry, Before you junk the Optimas on the advice of NAPA try a battery distributor for an evaluation. If they are in fact defective they may even give you break on replacements. Maybe you'll get lucky. Those Optimas are a lot of money to throw away.