2 6-volt or 3 12-volt?

[Sporty27K]

I purchased a 2015 Thor Windsport 27K in January 2014. I sat on the dealer lot for a year before we bought it and we have had battery issues from the beginning.
The batteries are 2 12-volt marine/rv and are in the process of being switched out.
The question I have is-should I get 2 6-volt or 3 12-volt batteries?
There is just enough room for 3 12-volt batteries but not enough room for 4 6-volt batteries.
We mostly boondock.
I also purchased a 160 watt solar panel to help keep us going.
So-2 6-volt or 3-12 volt?

I do plan on getting batteries with larger a/h ratings.

Thanks
Alan

[dpinvidic]

You can only go by the AH numbers, that is what really matters.
But if you have a space issue, I suspect that you will be able to find 3 12v batteries which will provide more overall capacity since I think you will be leaving less empty space.

It is likely that 2 6V batteries will be less total capacity..and your wasting open space.

I think I remember that 6v batteries will discharge deeper in most cases and for their size, they usually give a little more capacity..
Maybe someone who has recently done this analysis can comment.

Regards,

Dan

[1bigmess]

With the solar panels, I'd go with with the (2) 6v batteries. You will have plenty of capacity, and the batteries will receive some charge from the solar panel (160 watts at 13 volts is 12 amps, a decent charging rate as long as the panel is in full sun). If you are careful with the electricity usage, you'll never harm the (2) 6v true deep cycle batteries by bringing them under a 50% state of charge, and save just a little weight for other things you want to bring with you.

[bobandshaz]

Interesting issue. I always thought 6v was the way to go. Glad you haveasked the question.

[okcnewbie]

It doesn't really matter like it used to. The batteries are the same technology. This is perhaps a little simplistic but you are going to get about 200 a/h per 100 pounds MOL.

As far as boondocking goes; It depends on the length of your average stay and how much you rely on the batteries.

Example; I have 400 amp/hrs and if I only boondocked for 2-3 days at a time I wouldn't even need solar. I could use everything in the coach pretty much all day long for 2 to 3 days. Go home and recharge the batteries and do it again.

My advice is; Get new batteries and a good meter first.

[mbridinger]

Originally Posted by 1bigmess

With the solar panels, I'd go with with the (2) 6v batteries. You will have plenty of capacity, and the batteries will receive some charge from the solar panel (160 watts at 13 volts is 12 amps, a decent charging rate as long as the panel is in full sun). If you are careful with the electricity usage, you'll never harm the (2) 6v true deep cycle batteries by bringing them under a 50% state of charge, and save just a little weight for other things you want to bring with you.

X2
I have the same situation with space. I constipated on the subject for a week. Yesterday I installed 2 Trojan T105's for $198. This is what I had before and I boondock for days at a time and never had an issue (135watts of solar). I think the old batteries were 8 years old. I will do a better job maintaining the new ones. these batteries have been around a long time with great results. i see no need to change until Tesla becomes competitive.

[twinboat]

Trojan T1275 are 150 AH 12 volt deep cycle batteries.

If they fit, 3 of them will be give you about the same as 4, 6 volt batteries.

They are deep cycle batteries not hybrid "Starting / Marine" deep cycle design. They should hold up for many cycles.

[mbridinger]

Originally Posted by twinboat

Trojan T1275 are 150 AH 12 volt deep cycle batteries.

If they fit, 3 of them will be give you about the same as 4, 6 volt batteries.

They are deep cycle batteries not hybrid "Starting / Marine" deep cycle design. They should hold up for many cycles.

That is a good option. At $600 for the three vs $200 for 2(6v) I can run the generator for 1 hour a day and save some money.

[Scottybdivin]

If you are sure you can fit 3 T-1275, that would be my choice. They are a little more expensive than the 6V, due to production levels, but if your space demands the 12V, it would be worth it. I just bought 8 T-105's @ $129. That would only be $516 for the same Ah.

[Sporty27K]

Well looks like the dealer will be replacing our 2 12 volt size 24 batteries with 2 12 volt size 27 Interstate batteries. Not exactly what I wanted but they are paying for everything so what the heck. Will probably add another size 27 battery very soon. That with the 160W solar should take care of us for now. Next change will probably be to a 6 volt battery set-up. I will probably do a mod to fit 4 6 volts in and add more solar. We do a lot of boon docking and the DW needs to be happy doesn't she?

[1bigmess]

I took the batteries that the dealer gave me for "free" (part of the deal with a brand new trailer, but since I didn't really plan on them, I guess they were kinda "free")and sold them on CraigsList for $100/each. That made it very easy to buy 2 really good Interstate brand GC2 batteries.

[wa8yxm]

MARINE/deep cycle or MARINE/rv batteries are basically starting batteries.. with minor attention to deep cycle needs.

Most starting batteries if you run 'em down too far.. are toast.
MARINE/deep cycle MIGHT recover, once, if you are lucky But running them down to 50% state of charge NOT recommended.

True DEEP CYCLE have no problem with running down to half full (50% state of charge) provided you re-charge promptly.. and in fact can recover from much lower states of charge without too much loss of life.

I would go to DEEP CYCLE (GC-2 Golf Car batteries are DEEP CYCLE)

[dagmandt]

Look into Crown 6v deep cycle batteries. True deep cycle. Crown batteries are exceptional quality. I have two crown 260Ah 6v batteries. I charge them with 15.5v to a resting voltage of 12.8. I regularly run them down to 12.2v and get 4 days without a charge if needed (12v tv, power stabs, power awning, power tongue jack, LED lights, occasional furnace, fantastic fans for bathroom and sometimes through the night in bedroom, laptop and phone charging). I generally charge every 2 days because I only need to run the generator for 1-2 hours to get to full charge that way. With the Honda 2000i there is little noise when charging as it is near idle when charging. No dependency on the sun. We are in WA and camp in any weather and in the forest much of the time.

http://www.crownbattery.com/crown-ba...ectric-vehicle

Darren

[Kiwi]

Have you looked into AGM batteries. They are sealed glass mat and have great deep repetitive cycling capacity. I suspect that three 12v AGM will give you much more bang.... but at a little more buck.