Batteries- 12v vs 2 6v

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NEWBIES

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Hi new to forum but I had question about switching my batteries. We have a 1995 Winnebago Vectra pusher that has 3 batteries 2 for the house and one for the main engine, they are all 12v but my issue is the house batteries only last 3-4 years and I was wondering if I would be better off wiring 2 6v batteries together to make 12v for the house and leave the main battery a single 12v. I have heard that the 6v batteries are made with heavier plates and together would have more amps than the 2 12v together. I would appreciate any help thanks  Newbies
 
NEWBIES said:
Hi new to forum but I had question about switching my batteries. We have a 1995 Winnebago Vectra pusher that has 3 batteries 2 for the house and one for the main engine, they are all 12v but my issue is the house batteries only last 3-4 years and I was wondering if I would be better off wiring 2 6v batteries together to make 12v for the house and leave the main battery a single 12v. I have heard that the 6v batteries are made with heavier plates and together would have more amps than the 2 12v together. I would appreciate any help thanks  Newbies
Depends on the capacity of the batteries. What do you have in there NOW? If it is a Marine Battery, the best thing you can do is remove it and change it with a true deep cycle battery, which usually will NOT have the words "cranking amps" on it at all. True deep cycle batteries will last a lot longer as your house battery.

Often when six volt batteries are wired in series, they are often golf cart batteries which are always true deep cycle batteries. But pound for pound, you can get a 12volt true deep cycle battery that will do just as well. Just stay away from the words "Marine" and "Cranking Amps". A decent RV house battery will NOT have such words.

Bottom line is that there is usually no reason to change from a 12 volt battery to two six volt batteries in series in the same amount of space, etc. Just get a better 12 volt house battery. But check the specs when you compare batteries. Compare words such as AHs, Reserve Capacity, but you do NOT  even want to see the words "marine" or "cranking amps" on  a decent house battery.

-Don-  Reno, NV

 
Some good reading right here:
http://www.rvforum.net/joomla/index.php?option=com_content&view=article&id=506:choosing-the-right-battery-for-your-rv&catid=39&Itemid=132

 
Moving to two 6 volt golf cart batteries would be a good move. They will usually be less expensive than their 12 volt counter parts of the same capacity. And as you mentioned there is a difference in the plates. Whether or not you use it with an inverter and the size of load put on the inverter make a big difference. Also the type of converter/charger will make a big difference in the longevity of the house batteries. You may have a fixed voltage converter/charger which is hard on batteries.
 
Thanks for all of helpful comments I think we had the wrong style batteries in the coach for house power I will replace the with true deep cell batteries and give that a try
 
Al always, I need to make my usual house battery recommendation - AGM (absorbed glass mat) battery chemistry. These have less internal resistance, charge faster and self-discharge slower. They survive deep (<=50%) discharges better than traditional flooded cell chemistry. They are more expensive but last longer - more bang for your buck.
 
Yep... I agree with John completely. First, there's no doubt that T-105s are excellent batteries, but our AGMs have been the most well suited RV batteries we've ever had for boondocking. We rarely run them down below 70%, but when it happens, they can accept the charger's full 150 amp output for quite awhile. They recharge noticeably faster than our "standard" lead/acid batteries did.

I never minded having to check the water levels of our batteries, but I have to admit that it's nice not having to worry about it with our AGMs. They are truly maintenance-free. No outgassing, the ability to mount them in any position... there's a lot to like about AGMs.

Kev 
 
Which brand of AGM battery have you guys had the best results with? I was introduced to Odyssey batteries about 12 yrs ago. I don't remember the size I installed in our 98 Chateau, but it worked very well for about 7 yrs. Our converter died & ruined it when it did go. I really like the quick recovery time! Our MH only has one coach battery, so had been running out of juice in before one overnighter was done. After installing the Odyssey we could go two nights with the furnace on at 55- 60 degrees. I also use them in my cars. I have an Odyssey 925 in my Street/strip 99 Dodge Dakota that has a built 10.8-1 compression 360. It cranks faster than anything else I have had in there!
 
Odyssey makes a good battery - they are one of the few specialty manufacturers. Most brand names buy batteries from one of the Big Four battery makers and just put their own label on them. They are a "starved electrolyte" design, which most of us know as the AGM battery type. Other excellent deep cycle battery specialists include Trojan and Lifeline/Concorde. I would recommend any of those brands as long as the battery specs are equivalent.

Odyssey doesn't get any more power out of a given size than any other quality battery brand - there is only so much lead you can get into a given case size and that is the limiting factor on capacity. And all AGM types with the same specs pretty much perform the same on cycles and recovery time. Bottom line is to compare the battery type and the performance specs (amp-hours @ 20 hour rate or Reserve Capacity). Weight (the amount of lead inside) is another solid clue when comparing batteries.
 
The Lifeline model of AGM is the top of the pile - they are supplied to the military. I've had two sets of Lifeline AGMs in our now 12 year old Horizon and the last set I installed three or four years ago should easily last another five or six years.

My first set of Lifelines was their GPL-31T (group 31) - weighs 64 pounds and 105 amp-hour discharge at the 20 hour standard.
Next set (and current) is their  GPL-31XT - weighs 74 pounds and 125 amp-hour discharge rate at the 20 hour standard.

So they managed to pack 10 more pounds into the same case size and added 20 amp-hours of capacity. I moved up from 315 amp-hours to 375 amp-hours in the same tray. Every amp helps.

Now for the major downside - they are very expensive, about $365 each without shipping. I think I found an on-line dealer that sold them for ~$400 including shipping.  The major upside - they will last a very, very long time if you take care of them (no discharges below 50%.) They can be mounted in any position inside or in a bay and are absolutely maintenance free.
 
John Canfield said:
My first set of Lifelines was their GPL-31T (group 31) - weighs 64 pounds and 105 amp-hour discharge at the 20 hour standard.
Next set (and current) is their  GPL-31XT - weighs 74 pounds and 125 amp-hour discharge rate at the 20 hour standard.

Why not GPL-4CT? 6 volts. I have 4. 220 amp-hour discharge rate at 20 hour std. So I have 440 amp hours. Weight difference = 42# more. 65 more amp hours. I believe we have the same size Kwikee battery tray.
 
NoMoreAZ said:
Why not GPL-4CT? 6 volts. I have 4. 220 amp-hour discharge rate at 20 hour std. So I have 440 amp hours. Weight difference = 42# more. 65 more amp hours. I believe we have the same size Kwikee battery tray.
Right, should be the same battery tray. I just didn't want to mess with more cabling and I think those six volt models are taller.
 
Ya they are about 1-1/2" taller.  I couldn't get the trays closed on my 5er so I had to get new battery box. 
 
I swapped my 3ea GP31 12v house batteries after the 1st year in Quartzsite and ran them down several times hard after a pretty cold week in the low teens, they just weren't cutting it. Those were replaced by U2200's that ran 7 years because I lost a cell, and it was getting time anyway. The new T-145 set (520ah) can run @ 20ah for 23hrs before shutdown @10.5v (as tested, and only once). I'm not sure if an AGM can do that in this space. Because the Winnie's aren't easy to water up, I have a watering system installed, but still pull them once a year to make sure they are healthy and the valves are clear. That extra work for me for the additional capacity outweighs service convenience. TRUE 12v deep cycles aren't easy to find either. As mentioned above, be aware of "Marine" or "Starting/Trolling" they ain't the same.
 
SCVJeff said:
... As mentioned above, be aware of "Marine" or "Starting/Trolling" they ain't the same.
Yeppers. Some of them even look like they have a sealed top inferring maintenance free but they lie  :p. The lid/top can (and should) be pried up for cell maintenance.
 
Has  anyone figured out how or where to put 4 or 6 six volt coach batteries in a Winnebago Journey DL?
 
Rattleback said:
Has  anyone figured out how or where to put 4 or 6 six volt coach batteries in a Winnebago Journey DL?
what size? The 32T has a different arrangement but you can easily fit four in the battery trays above that
 
You can choose different case-size batteries based on the dimensions of the battery compartment. You may have to buy more expensive 12v deep cycles to get a different case size, but if you are buying AGM batteries there isn't much price difference on a per-amp-hour basis. Flooded cell 12v deep cycles are a specialty item, though, and cost much more than GC2 golf cart 6v batteries.

12v AGM deep cycles are readily available in BCI standard sizes of 24, 27, 29, 30 & 31. $d & 8D too.

BCI standard for Battery Council International and is the trade standard association for battery manufacturers. BCI defines the dimensions for the standard battery case sizes that all the manufacturers adhere to. See http://www.evdl.org/pages/bcigroup.html for the dimensions of each size and you can figure out what fits. GC2 is a BCI standard too and that is the 6v "golf cart" battery size.
 

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