2 6 volt or 3 12 volt batteries

[allen8106]

Originally Posted by Mr_D

I'm sure lots will disagree but I'd go with the 2-6volt TRUE deep cycle.

Same here.

[SSG Scott]

6 volt golf cart batteries are a best choice as the thicker plates allow them to last much longer and making them better deep cycle batteries. If you plan to camp and boondock a lot in the years to come LiFePo4 batteries are a true game changer. While they are an investment, Battle Born is a drop in replacement that weighs 30 lbs and had more power delivered capacity than a pair of golf cart batteries. The can be expected to outlast your next several rigs with a reasonalbe lifetime of 20 years. We can even run our airconditioning on them.

-Scott

[Ret.LEO]

2 Lithiums. Only weighs 29lbs each, can be taken safely down to zero. Will charge back 4 times faster, good for 3-5000 charges.

[Riverbanker]

I have an Itasca Navion (2014) with 2 stock deep cycle batteries ( 650 amps each) and without getting too technical, I’d like to know how long these should stay charged using nothing but the gas fridge and nothing else ( except smoke and gas detectors). By morning these are down to about 11 volts. It was worse until I disconnected the inverted which for some reason was drawing a lot of voltage. Nothing else is turned on. Thanks.

[twinboat]

Longer then 1 night. If you are charging them fully, and they are any good, probably a few days to a week or more, just running the fridge controls and detectors, while in gas mode.

650 amps is cranking amps, not a useful detail in deep cycle batteries.

If they are deep cycle, they will be marked with AH or Amp Hour capacity. The more the better.

As weak as they sound, charge them up, disconnect them, and see if they drop in voltage with nothing connected. If the drop, its a sure sign of bad batteries.

[Riverbanker]

Thanks for the feedback on batteries, very helpful!

[SSG Scott]

Originally Posted by Riverbanker

I have an Itasca Navion (2014) with 2 stock deep cycle batteries ( 650 amps each) and without getting too technical, I’d like to know how long these should stay charged using nothing but the gas fridge and nothing else ( except smoke and gas detectors). By morning these are down to about 11 volts. It was worse until I disconnected the inverted which for some reason was drawing a lot of voltage. Nothing else is turned on. Thanks.

An inverter just being powered on (not powering anything) consumes current. Small inverters will draw 1/2 amp just being turned on (12 amp hours a day which is about 1/4 the capacity of most deep cycle 12 volt batteries) while larger inverters will commonly consume 3 amps, which is 72 amp hours a day. Most deep cycle 12 volt batteries have a 100 amp hour capacity and should never be drawn down below 50% to keep from damaging the battery, which means you have 50 usable amp hours available.

The bottom line- only turn on the inverter when you need to use it and then turn it off when finished or buy a super efficient inverter like a MorningStar Sure Sine inverter (they consume .05 amps powered on or 1.2 amp hours a day- which is what I leave on all the time in my RV).

-Scott

[consolenut]

Originally Posted by twinboat

As mentioned, you want to look for the most AH capacity.

Some 12 volt Marine/RV batteries have only 45 AH capacity. 3 only gives you 135 total AH.

A 6 volt batery will give you a minimum of 190 AH. 2 together is still 190 AH but at 12 volts. You can find higher AH capacity then the minimum, up to 245 AH, or more, if you can fit taller batteries.

If you find 3, 12 volt, 100 AH batteries, then your ahead of the 6 volt setup.

The 12 volt dual purpose batteries may not last as long as the 6 volt deep cycle, but if your not dry camping almost every day, you can get a few years out of them.

I would alway suggest 6 volt batteries because they are spicificicly built for deep cycle, electric golf cars.

I couldn't fit the 6 volt height in my new MH, so I'm using 2, 12 volt GP31 Marine/RV types. Only been 6 months, so no length of service data yet.

i use 6 of the group 31 interstate extreme cycling batteries. so far so good 195AH each

[twinboat]

Originally Posted by consolenut

i use 6 of the group 31 interstate extreme cycling batteries. so far so good 195AH each

More likely 195 RC. That's about double the AH rating.

Still, 600 AH is reasonably large battery bank.

[Pappion]

Originally Posted by wingnuts

Its time for new batteries and noticed I have room for 3. What do you guys think would be better for boondocking with 400 watts of solar, 3 12 volt marine batteries or 2 6 volt golf cart batteries...?

And why

The golf cart batteries are far more robust. Still they will be slow to charge. Watch your charge voltage vs. temperature.



100 Watts of solar at 14.4V was boiling the 2 size 27 cheap old flooded cells that came with my camper. Most of that charging power was wasted. They were slow to charge, like most flooded cells.
I now have 2 size 31 AGM batteries. AGM can charge 4x faster. Be careful not to overcharge.

I have a better MPPT solar controller with remote temperature probe. EPsolar Tracer MPPT is programmable. It can better match the Outback 106NC AGM Nano Carbon's charge voltage. Arizona Rim Country (mountains) can get hot.

[153stars]

I will comment on Sams gray better ECG2 on my TT.... I abused them terribly with just an 80s converter for 6or7yrs. Still working ...I know they went nearly flat in winter a more than few times jumped with truck running a bunch. They are 125 ...35more than $90 black ones. I used to go through 12v boat batts in just 3years tops.
I didn't know about Trojans then AMG has come down since then too. Golf cart place has US AMG for $175 no core charge prob my next buy or Trojans
I weigh my options against core charges if I'm short 2 batteries now some core as high as $36.
And if I screw up and flatten them.
LI batts can't be charged cold and are dropping in price every year... There are 1000 posts on batts got the cash go big.

[Smitty77]

Specifically to the OP's question, as you can see no shortage of different perspectives and viewpoints on this question, my answer would be:

2 sets 6V Deep Cycles over X's 3 12V Marine.

If you have the budget, incrementally more expensive:

> X's 3 Trojan T-1275 (Which I believe have 150A each, for 450AH's available.)
> X's 3 Lifeline GPL-31XT's (If they'll fit. And yes, I'd take the lower 105A for 315AH's over the T-1275's 450AH's - If (IF), I had the charging sources capable of pumping in some AH's... (I'd sacrifice the 135AH's for faster recharging time while boon docking - the stated objective.)
> X's 3 Lithium of your choice and capacity size, depending upon wallet depth!

My best to you and all (And a good thread, with lots of great overall info and links!),
Smitty

[McRod]

2 x 6v Trojan T 125's

More AH, better deep cycling, better recharge rate, better price/AH.

[LeisurePursuits]

If you have an inverter and are using it to run youR microwave or coffee maker then you may want to do 12v in parallel. In my experience they can deliver more current with less voltage drop then 6v in series due to less resistance. YMMV.