Newbie Battery Question

[ColdEspresso]

I recently bought a 78 Caravanner and picking it up next week. I have been told by an inspector that the batteries are weak and the Univolt is good. I am not sure if the unit has 1 or 2 batteries. Which setup is better. Can someone tell me what batteries I should replace it/them with? Deep cycle? Open or closed cell? What will perform best and give me the greatest longevity? Any idea on price? Also, I plan on eventually upgrading to a newer Intellipower system. Will I be able to use the same batteries or will I need to replace them again.

Thanks,

Mario

[Killo1]

I've been told, and truthfully don't know why, that you should use 2 six volt batteries in series. Supposedly they last longer. Do some research on it. I've been told by quite a few different people that it works.

[bhayden]

I'd go with the maintenance free. Good quality batteries today will last a long time and I've found the maintenance free batteries give off less corrosive junk when charging. Pulling out the battery and checking electrolite levels is a headach I can live without. I do watch the charge indicator on the battery. I turn off the Univolt when it's showing fully charged and try to turn it back on when it "dips into the yellow". Haven't check what battery voltage that cooresponds to yet.

My neighbor was told to go with two 6V deep cycle batteries for his motorhome. I don't understand why you'd want to do this. Battery terminals are a pain to maintain. Unless there's some wierd space constraint I think you can get more amp/hours in a single 12V package than two six volt batteries and certainly easier to take out and charge.

Remember the battery is what activates the trailer brakes in "break-away" mode so you don't want to be travelling with it dead. Your TV harness should recharge the battery but it could take some time before it has enough umph to stop the trailer. I've considered adding a small isolated motorcycle size battery as a reserve.

-Bernie

[dwightdi]

Deep cycle batteries from Walmart are nice and if they have a problem, within the first two years, they give you a new one (after they test the old one) at no cost to you. How can you go wrong with a free replacement?

[crowbar68]

definetly deep cycle as you can charge and discharge w/o damaging the battery like an automotive one. i believe the 6volt set up gives you more ampere hours (capacity) than a single 12v. but you will need the space. measure twice buy once! you can always retro fit!

have fun

crowbar

p.s. i have a die hard from sears for around a hundred

[Inland RV Center, In]

Originally Posted by crowbar68

definetly deep cycle as you can charge and discharge w/o damaging the battery like an automotive one. i believe the 6volt set up gives you more ampere hours (capacity) than a single 12v. but you will need the space. measure twice buy once! you can always retro fit!

have fun

crowbar

p.s. i have a die hard from sears for around a hundred

Two 6 volt batteries in series at 100 amp hours is 1200 watts.

Two 12 volt batteries in parallel at 50 amp hours is 1200 watts.

Same difference4.

However, when the series setup has one battery that gets weak, or bad, it's done.

When the parallel setup has one battery that goes bad, disconnect it and you still have some power left.

Two sixes, in series, in a travel trailer, are never superior to two twelves in parallel, given the same wattage.

Further, big 6's are much harder to find than big 12's.

Simple ohms law, E=IR or W=EI

Andy

[peegreen]

There are loads of posts on the forums for batteries and a lot of enthusiasm on the subject similar to polishing and hitches. Wet cell, gel cell (optima) or AGM (glass mat) all have pro's & con's. I searched them all when I needed to replace my pair. Gel - zero maintenance, no off gassing, higher initial cost, lower capacity. AGM - same as gel, but these batteries can be run right down to parade rest. Wet - requires checking/maintaining voltage and electrolyte. Cannot go < 50% or battery life will be shortened. I ended up witha pair of group 27 Interstates and have been very happy. I use a small LCD voltmeter to keep track of charge. Better then control panel state of charge meter. I plug trailer in once a month if Im not using it and keep a voltage vs % charge posted inside a cabinet door. I think this route gives the greatest bang for the buck with very little extra effort. If you want to never check electrolyte, go with the gel. If you will be doing a lot of boondocking and will run the batteries all the way down, check out the AGM. Personally, I'd stay away from the WM battery unless you're selling the trailer and advertising new battery.

[ColdEspresso]

Thanks for the great responses. I am also thinking of upgrading from the Univolt to an Intellipower Converter/Charger. I understand that it is quiet and more efficient than an older univolt. Do any of these batteries perform better with this charger or will the univolt be OK?


Thanks,

Mario

[GreatPumpkin]

Originally Posted by peegreen

.....Personally, I'd stay away from the WM battery unless you're selling the trailer and advertising new battery.

Curiosity - Why?

[peegreen]

Originally Posted by GreatPumpkin

Curiosity - Why?

Get what you pay for.

[GreatPumpkin]

FYI....

EXIDE http://www.exide.com

"About Exide Technologies
Exide Technologies, with operations in 89 countries, is one of the world’s largest producers and recyclers of lead-acid batteries."

Manufactures most of the batteries out there:

Exide, Orbital, Stowaway, Nautilus, Champion, Trailblazer, GNB, Nascar Performance (official battery of Nascar)

Private label:

Wal-Mart, Sam's, Les Schwab, Napa, Schuck's, Big O Tires, Parts Plus, NTB, Tire Kingdom

[Inland RV Center, In]

Originally Posted by ColdEspresso

Thanks for the great responses. I am also thinking of upgrading from the Univolt to an Intellipower Converter/Charger. I understand that it is quiet and more efficient than an older univolt. Do any of these batteries perform better with this charger or will the univolt be OK?


Thanks,

Mario

Your comparing an older Univolt to a new Intellipower charger.

I might suggest that you also look at the new Univolts that Airstream has been using for several years, since they are trouble free.

Might think about why there are so many rebuilt Intellichargers on the market.

Also a noisey Univolt has no effect on it's ability to charge correctly.

Andy

[lewster]

FWIW,

I have replaced a bunch of Intellipower converters and a few Univolts, but only 1 WFCO converter. I was so impressed by it's operation that I pulled the new Parrallax that came with my CCD and replaced it with a new WFCO.

On the battery topic, 6V golf cart batteries have much thicker plates than any 12V battery and have a much higher charge/discharge cycle life. That's why they are used in golf carts! Run down and charged each day and last a few years. My personal choice........a pair of Lifeline 6V golf cart batteries in series.

*NOTE*
This post is for informational purposes only and reflects the opinions and experiences of the poster! Your results may vary!!!

[Inland RV Center, In]

Of course the 6 volt batterys have large plates than a 12 volt.

It's because it's 6 volt.

A 24 volt battery has smaller plates than a 12 battery.

That's the way it is.

6 volt batteries in an Airstream trailer offer "nothing" positive, but do add to the negative, in that a series setup has more disadvantages than a parallel setup.

Airstreaming use is far removed from a golf cart, which is far removed from aircraft, etc.

Andy

Andy

[bhayden]

Originally Posted by lewster

FWIW,On the battery topic, 6V golf cart batteries have much thicker plates than any 12V battery and have a much higher charge/discharge cycle life.

Ah, finally a sensible reason for using 6V batteries. All batteries are composed of 2V cells in series. When one cell dies (the usual senario for a dead battery) your done for. Although I'm not fond of the extra external connections it has one advantage in that when one of the batteries dies you can replace half the system. Comparing two 12v in parrallel is only a fair comparision to a four 6V setup. The 6V setup is going to give you more fail safe capability because two of your batteries can die and you can still cobble together a working 12V system. In fact, three bum 6V batteries could be made to work in a pinch to provide 12V. Remember, the most common failure is one of the 2V cells so three 6V batteries producing 4V each is 12V. Not a great system but might "save the bacon" so to speak if you're boondocking.

Plate thickness isn't related to voltage. Batteries designed for offroad use have thicker plates and also more space at the bottom for precipitates to accumulate before killing the cell. New technology like the Gates "jelly roll" are even better.

Battery use varies a lot depending on how people use their trailer. Some people are either hooked up to the grid or the charging system on the TV virtually 100% of the time. Other people are regularly depending on their battery to provide power for as long as possible (gimme all you got Scotty Golf cart battery use really isn't so different than this. I'm guessing the majority of carts are owned by golf courses rather than individuals. Running as a buisness and buying in volume the market will be very competitive and not so swayed by fancy advertising. I am surprised they use a 6V system. It seems cutting the amperage by going 12 or 24V or even 48v would make sense. I believe most of the little kid toy electric vehicles use 48V battery packs. Portable tools have migrated to increase voltages over the years and have become much better.

For me the simplicity of a single 12V maintenance free "gel cell" is the way to go. I know I'm not going to be religous about checking electrolyte level and traveling a lot of rough roads is death to conventional lead acid cells anyway. Although I hate them on the TV the GM "side post" design makes for a much cleaner attachement. And as long as you get the dual terminal style you can still get/give a jump start easilly). If I were going to go custom I'd order an array of small 6V 12 amp hour starved electrolyte batteries with Faston connectors and build multiple custom 12V battery packs with isolation. If you look inside a computer room UPS that's what you'll see.

-Bernie

[ColdEspresso]

Thanks for all of the input... I decided to go with a new Univolt per Andy's suggestion and also the guys at AS agreed. I figured that was the best solution and I will keep you posted if there are any issues.

Thanks again...

[davidz71]

Mario,
I had 2 Delco Voyager group 27 deep cycle RV batteries in my '77 Excella 500. I used them for over 4 years and kept them charged with a 5 watt Pulse Tech Solargizer solar system. They never seemed to get low even though I calculated I was discharging them close to 50% each 3 day hunting trip. I guess the Solargizer made up the difference the other 4 days I was not there. This is contrary to what some on the board would have me believe. They are really good batteries that some on the forum have said lasted up to 10 years. If I can figure out how to get 2 of them on the tongue of my trailer then that is what I will go with. I presently have one Walmart Everstart 115 amp hr. battery which is about 2 years old and no problems so far.

[scottanlily]

My small input is that the 6volt golf cart battery is great for long duration use
as golf carts are .I used to service golf carts for a golf course in town as well as their toro mower machines .Those carts go all day on a charge .The idea of 4 of them together for seriouse boondocking sounds like a good plan as
your needing the best ,long lasting ,duration batteries .But as Andy said golf
carts dont have 12volt lights ,refrigerators and such .The local rv outlet
I work with and buy from have these deep cycle 12volt batteries ,they are
maroon in color and are very popular and are a large case size .It would seem
at first glnce they might be the heavy duty ticket .Someone here might know
the ones I mean .I use a long narrow forklift/industrial type battery in my 60
trdwnd as that is what fits .works great ,but not the optimum setup .But
then I do have the honda eu2000 on hand .

Scott

[lewster]

Scott,

The golf cart that I have has 6- 6volt batteries. They are connected in a series/parallel system that gives a 12 VDC output. Each pair is connected in series, and then the 3 pair are connected in parallel. They are 200AH each, so the 3 pair have a total of 12VDC with 600 AH total capacity. BTW, the cart HAS headlights and 2 fans, all 12VDC.

Also, FWIW, almost every major premium motor home manufacturer (Monaco, Country Coach, American Coach, Newmar) have gone away from the use of 12 VDC 4D wet cells and have replaced then with either 4 or 6, 6 VOLT AGM GOLF CART BATTERIES connected as I described above. Their thinking on the issue is deeper discharge capacity than 4-D's, longer life and higher AH output. They must have run the numbers and found this to be the way to go. It's all I have been seeing on the newer diesel MoHo's.

[63air]

I went with the Optima battery and have been very pleased. Pricey but worth the money, lots of advantages in this newer technology.