Best batteries for boondocking

We have 1 100w solar panel installed and as Jack&Janet predicted were ardding a second.

In the meantime we need to upgrade our two marine/rv batteries to something more robust. What have you all found works best? The Golfcart batteries I've seen look too tall for the compartment on our 2005 17T.

I'm looking at proper deep cycle batteries and thinking of even going for lithium ion.

Montana - Lithium would be VERY expensive, I think.

I'm able to put two Group size 24 wet cell batteries in my trailer. Others have room for the larger Group 27s, which give you more capacity. If you could fit the two 6V golf cart batteries in (wired in series) they should be even better (more capacity). The goal is to keep the charge state in them as high as possible, so, more capacity = a higher average charge state and should give you more life. But, I think your trailer is like mine and you will only have room for Group 24 without building a bigger battery box. That project is something one member did - you MAY be able to find his post. I think it's fairly "doable".

I would NOT try to use the "gel" batteries. They cost about twice what a lead-acid battery costs and don't really give you significantly more capacity.

The problem with Lithium-ion is that the technology is still awfully new. They've had some widely publicized problems, such as overheating in cell phones and a fire in a Boeing 787 Dreamliner. Besides the expense, I simply don't trust them. My power tools use them and so do my laptops and cellphone, but I would not want them in my trailer. One interesting fact about Lithium-ion is that the ideal charge state for storage is 80%. I think that's pretty much the desired level when the things are in use too. I don't know how the heck you can maintain that level without special electronics.

- Jack

DaveL put a pair of 6 volt golf cart batteries in his 2409T by lowering the battery box a couple inches. He said it was an easy task by extending the length of the mounting straps.

Another argument for 12 volt batteries over six volt is that if one battery goes bad in the 12 volt arrangement you still have at least one battery that is useable. In a six volt series-wired set-up, unless you have TWO banks of batteries ( four total), if one goes bad you are essentially without electricity. Gel cell and the "matt" battereies ( AGM?), often need different and touchier re-charging set-ups in terms of charger/converters and charge controllers. Unless you are really into all of this and enjoy it-I would recommend shopping for good, deep cycle, 12 volt wet cell batteries. Its the easiest system to use for these trailers, in my opinion.

Rick

12 Volt deep cycle batteries are easier to find in a pinch.

I'm wondering if I could squeeze in group 27s. There's a lot going in that battery box.

I found one on Amazon that measures 12x6.7.
I roughly measured each battery space at 11"x7"

montana said:

I'm wondering if I could squeeze in group 27s. There's a lot going in that battery box.

I found one on Amazon that measures 12x6.7.
I roughly measured each battery space at 11"x7"

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Based on my trailer, which should have the same sized battery compartment, I'd say no.

- Jack

I have 2 group 29 batteries from Walmart in my 2806C

hilltool said:

Another argument for 12 volt batteries over six volt is that if one battery goes bad in the 12 volt arrangement you still have at least one battery that is useable. In a six volt series-wired set-up, unless you have TWO banks of batteries ( four total), if one goes bad you are essentially without electricity. Gel cell and the "matt" battereies ( AGM?), often need different and touchier re-charging set-ups in terms of charger/converters and charge controllers. Unless you are really into all of this and enjoy it-I would recommend shopping for good, deep cycle, 12 volt wet cell batteries. Its the easiest system to use for these trailers, in my opinion.

Rick

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True, but if one 12v goes bad then it continually drains the good 12v battery until it is also dead, and if not caught the good battery will soon be a bad battery. You would have to catch it going bad pretty quick to disconnect the good battery, or you would have to recharge the good battery, which is not an option with 6v. But, if you can recharge it then you can supply the same 12v over the good and bad pair of 6v batteries and at least make the lift.
Ive never heard of one 6v going bad, but Im sure they do.
Maybe set your pair of 12v batteries up so they are separated from each other yet still power the same electrical system, if that is even possible…
To me is not enough of an issue to leave my pair of 6v batteries.

Universal Battery UB121000 AGI

I'm looking at installing a Universal UB121000 battery in my well behind the tongue. It's a size 27.

Two questions?

Has anyone put one of them in your tongue well? Although the height dimensions says 8.2 inches, it's actually 9.1 inches to the top of the terminal. I think that would barely fit, but thought I'd check first.

Also , it's rated fairly high for a deep cycle battary, but I can't find any CCA on it. So, will it have enough power to lift my trailer up?

Ken

Raider, I answered your question in your other thread.

- Jack

If your trailer has a couch with storage room underneath at the front of the trailer like mine ,only a few feet from the tongue well, there's no reason you couldn't place a second battery there, wired in parallel to the one in the tongue well. You'd want to use an identical battery with heavy duty, large gauge battery wire. You could place a second battery even further from the tongue and probably increase the wire gauge because of the higher resistance. You could also used a double pole switch to isolate the second battery from the first if you wanted.

If going to dual batteries I have read that you only want to use matched ones and the same age or the weaker one will drain from the stronger one. I think I said that right.

i totally agree hilltool!

jeanj that's what i use the group 29 /125 amp hrs. w/ reserve, they have served me well!

Been using the Autozone deep cycle/blue top battery, seems to be pretty long lasting.

Anyone put two 6 volt batteries on either side of the camper? Is the distance an issue?

marininn said:

Anyone put two 6 volt batteries on either side of the camper? Is the distance an issue?

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I don't think the distance is a problem, but you need a VERY large gauge battery cable to connect the two. And then, you need trailer cables that are long enough to reach each battery that are also large gauge.

As long as the cable gauge is big enough, you should be able to put the batteries anywhere. You are drawing very high Amperage from the batteries when you activate the lift motor. I think it's around 50A, but it may be more. You need wire that can support that current flow.

- Jack

Distance is a concern, but given the draw is for such a short time (20 seconds or so) I wouldn’t worry about it. Just be sure to have good-sized cabling.

As distance goes up, so does heating from resistance. As heating goes up, so does resistance, so they feed each other. I’m sure there’s a formula out there for distance/current draw = required gauge.

In race cars when we moved batteries to the back we generally went up (numerically down) a gauge or two to compensate for the extra 6-8 ft of wiring. But you could probably get by safely with typical 4ga.

There is a chart in this article that gives wire sizes: The 12volt Side of Life Part 2