Which batteries do I buy.

[Road_Phantom]

This spring I plan to buy new batteries for our 34 ft 5th wheel. We have room for three batteries. Is it better to have two six volt batteries instead of one twelve volt and is Interstate a good company.

[Smitty77]

Road Phantom wrote:
This spring I plan to buy new batteries for our 34 ft 5th wheel. We have room for three batteries. Is it better to have two six volt batteries instead of one twelve volt and is Interstate a good company.

As mentioned, it really depends on how you plan to use your rig, to determine the appropriate battery to choose.

If you have room for three batteries, you will get largest bank of AH's by going with 12V.

Which 12V, well that becomes the question of budget, and how much you want to spend:

-AGM's such as Full River or Lifeline, will cost you more.
-Trojan T-1275 are true deep cycle 12V batteries, and are also a good chance of change.
-You asked about Interstate. Well, they are not what the used to be. But, they are certainly no worse then any others of the middle of the pack of battery flavors:)!
-Some areas of the country. Sam's Club and Costco do have generic 12V Deep Cycle batteries. Usually Wet, but I've actually seen some AGM's in different regions. These Sam's and Costco's will probably be your best bang for the buck as far as price vs performance.
-And as mentioned, you can drop down the price point a bit more, and get a Marine Grade battery. Able to do both 'starter duty' and 'some deeper cycle usage' duty too - but a compromise on both.

If you do not yet have a battery management system (Not the 25. 50, 75. 100% light kind.), you might look into adding one of those first. (Search as lots of input on two or three of the more popular ones.). Then do a few pretend camping energy audits, to see what your actual usage is. Factor your charging capability, generator or solar or both - and your own personal threshold for being comfortable running a generator. And this will lead you to determine the battery size might work for you.

Really comes down to what you feel you want, vs how much you want to spend:)!

Best of luck to you,
Smitty

[azrving]

Trojan says 14.8 volts bulk charge. I charge my Sams club to 14.8 on solar and 14.4 on PD4655.

[CincyGus]

I went with two 12v Trojan 1275's in parallel. Pricey but plenty of AH's (150 AH each), true deep cycle and well know in the golf cart world to last 5-6 years with good maint (Adding Water, not discharging below 50%). I don't have any of the worries of if one goes out, not being able to run my 12v stuff and gain the benefit of the more AH's and the true deep cycle most move to 6v batteries for. My camper has an 11cf residential fridge on an inverter and I wanted to extend the time between running the genny when boondocking as much as my battery tray would allow.

[theoldwizard1]

Everyone has an opinion on batteries ! My un-scientific poll says the majority of people would recommend two deep cycle 6V golf cart batteries. The cheapest source is either Costco (Interstate) or Sams Club (Duracell made by East Penn). Lots of good reports on both.

Only you will know if this is adequate for your needs. (Fine for lunch stops or one night of boondocking without a residential refrigerator or A/C.)

Consider upgrading you converter. Most "stock" converter do not do a good job charging your house battery bank.

[GordonThree]

Theres a lot of assumptions being made about the likelihood of catastrophic failure.

If it were such a common problem there'd be a lot more relevant information about it. Rather than conjecture and third hand information.

For the hand wringing group you could use fusible links to parallel the batteries.

[time2roll]

A pair of GC2 will serve you well in most conditions and use patterns.
Have you had any issues with the current battery set up?

[wa8yxm]

GordonThree wrote:
Parallel batteries get used a lot, I don't see it all over the news about them exploding. Have a citation you can share?

You are making an assumption
you see "Exploding" and you think KABOOM!!!!! and bent metal and stuff flying.

What we mean when a battery "Explodes" is more likely a "POP" and acid all over the battery compartment. No bending of metal. just eating away of it. It is still and "Explosion" by definition but not a violent one.

I do not know that a battery in parallel with another will "expload" when one goes bad and I do run 4 parallel batteries (one of which is 2 six volt in series) but explosion protection is in place.

Eventually I will be all 6 volt's likely 3 pair total. but 2 pair for sure.

The big difference is the GC class batteries are DESIGNED for RV use and the Group XX are not.

[pnichols]

Boon Docker wrote:
The magic of 12v batteries in parallel.
If one fails the good one will disconnect itself automatically so it does not get discharged by the one that failed. :B

How true that "disconnect itself" is ... except it's the bad one that "disconnects itself" from the battery(ies) in parallel with it ... not the good one(s).

My experience over the years with failed 12V batteries is that they fail by going to "an open" ... not to "a short" such that any others in parallel with the bad battery would thus experience a high current rapid discharge ("explode"). From all I read, whole battery internal shorts are not a common failure mode for either 12V or 6V batteries.

The best way to short any lead acid 12V or 6V battery and explode it is to drop a wrench, or cats paw, or crowbar, or etc. across it's positive and negative terminals. That's called a whole-battery-exterior-short ... and can be very dangerous indeed.

[Boon_Docker]

The magic of 12v batteries in parallel.
If one fails the good one will disconnect itself automatically so it does not get discharged by the one that failed. :B

[travelnutz]

There's a lot more pertinent info to know as to which RV batteries are the smartest to purchase and use in RV's. Also depends if you have physical room for 1, 2, 3, 4, 5, 6, or even 7 batteries in your RV. Always smarter to only use deep cycle batteries as they have thicker plates inside and can be recharged a lot more times before battery failure occurs.

The odd number of batteries means to get maximum amperage delivered before needing to be recharged usually at 50% of battery capacity remaining and that's important. The same goes for both 6 volt golf cart type batteries (2 always req'd to make 12 volts) and 12 volt deep cycle marine batteries (each battery gives 12 volts.

For instance, you can't have (3) 6 volt GC batteries connected together to give 12 volts so only 2 can be connected giving 12 volts which then only gives the same total amperage capacity at 12 volts as a single GC 6 volt battery. 200 amps at 6 volts capacity and then connecting 2 together to double the voltage to 12 volts still only has 200 amps capacity, period! However, having room for 3 12 volt 100 amp capacity batteries actually gives 300 amps of capacity. 1-1/2 times the using of (2) 6 volt GC batteries in the same available physical space location.

With (2) 6 volt GC batteries and one fails you have ZERO usable 12V DC power at all. All circuits are unusable, period! With any number of 12V batteries and if all but one battery were to fail, you still will have all circuits powered and completely usable. Simply unhook any or all the failed batteries and just carry on with your life!

Our 5th wheel has 5 group 31 12V deepcycle batteries inside the front basement vented storage battery area and each of the all alike batteries have 120 amp capacity and thus there's 600 amps total capacity. Also defined at a 23 amp draw for 225 minutes each capacity. That's a total of 1125 minutes of a constant 23 amp draw capacity! The batteries also power our 2500 watt inverter and have never drawn the batteries below 50% yet. The joys of having adequate amps stored onboard!

All 5 batteries were all purchased at the same time and from the same place in June of 2010 and the cost was $92.61 each + 6% sales tax on sale here in Michigan less that 2 miles from our home and are still going strong yet today and we will wait until spring 2019 to replace them when we get back from our annual 2-1/2 months down in Florida. The will looking for them on sale again, Why not? 2 months ago the same batteries were on sale at the same place here for $99 each and almost bought 5 of them again there but decided to wait until next year and will buy 8 of them as will need to replace the 2 In the bed of our truck for the Lance TC and the one in the Lance TC which all 3 are wired (cabled) together as the Lance has a 1500 watt inverter inside and gives us 360 amps of capacity.

Years past, were had 2 RV's with GC batteries paired and they lasted absolutely NO longer than the 12V DC Marine Batteries at ALL before needing to be recharged. So now only use just 12V batteries as it makes so much better sense and they are available anywhere if needed.

To each his own!

[gmctoyman]

If you boondock you might be interested in this thread.

Clicky

[GordonThree]

Parallel batteries get used a lot, I don't see it all over the news about them exploding. Have a citation you can share?

[Matt_Colie]

rbp111 wrote:
I was thinking that if you have 2 golf sized batteries, and one battery goes bad, then you are out of all power. So doesn't it make sense to have 2 12 volt batteries, in case one goes out, you would have power.
Just asking.

RPD111,

That is the thinking a lot of people use, but the fact is that if one goes bad then the other (or that one - I have never been able to figure it out) will explode. In any case, you are still out of power.

I used to like paralleled batteries a lot. I kept gloves and baking soda on hand and had a framework for the insurance claim waiting in my computer.

Matt

[rbp111]

I was thinking that if you have 2 golf sized batteries, and one battery goes bad, then you are out of all power. So doesn't it make sense to have 2 12 volt batteries, in case one goes out, you would have power.
Just asking.