# 6 Volt Vs.12 Volt



## Livin4weekenz (Aug 26, 2007)

its time to replace the stock batt. in the outback and I am thinking about the two 6 volt swap but dont know the real advantages of doing so im sure they last longer but by how much?

Looking more for length of run time on the furnace as we will be doing some dry camping this fall and winter..we have a gen. but cant run it after 10pm in most cases. Any info would be helpfull..

thanks . John


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## PDX_Doug (Nov 16, 2004)

Hi John,

Going the 6V route will definitely give you more time. When we switched, we went from being able to last about 1.5 days, at best (albeit with the low-end batteries that the dealer installed new) to probably 4 days if we were careful. Add in a couple of hours a day on a generator, and you should be in great shape for the cold weather.

On the flip side, the batteries are much more expensive and heavier. Also, there is the risk that if one battery goes, you are totally down. With the 12V system, you can take one battery out of the loop and soldier on. Not so with a 6V system.

All in all, I think it comes down to your style of camping. If you are going to be doing a lot of dry camping, the 6V setup is a great way to go. If you will only be dry camping occasionally (if ever), then you may be better off sticking with a couple of good 12V batteries.

Hope this helps.

Happy Trails,
Doug


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## SDCampers (Oct 29, 2008)

From what I've read on here I must be the exception, but I run 2 group 24 Interstate batteries and have never gone below 2/3 on a 3 day dry camping trip. Some have been late in the season when we ran the furnace. I guess untill they let me down I'll stick with the cheaper 12 volt. we don't scrimp on the lights and stereo either, the radio/CD player is on most of the weekend.


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## Oregon_Camper (Sep 13, 2004)

I've been using 2x6v's on my Outbacks (current and prior) and LOVE them. Truth be told, we dry camp about 85% of the time, so everyone understand to keep lights off when not in use. I can go about 7 days without hooking up generator if needed, but I normally fire it up on the 5th-6th day to recharge all items (kids hand held games...iPad, Kindle, GPS for Geocaching, etc...)

Now, if you really want to jump in and understand the entire battery in's/out's.....read this page.

http://www.marxrv.com/12volt/12volt.htm


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## KTMRacer (Jun 28, 2010)

First, discussing 6V vs. 12V is kinda like discussing politics or religion!!

However, my experience is that for extended dry camping you want true deep discharge batteries, not "marine" or combination starting/deep discharge batteries. If you didn't specify anything when you bought your trailer, you probably ended up with the cheapest batteries the dealer or mfg could find. So one of the easiest and most available upgrade routes is 6V "golf cart batteries". Two in series gives you about 245A hrs, vs. 160-200 for typical dual 12V. I use two 6v trojans and yes, we can do days (4 or more) between charges w/o going below 50% SOC even using the furnace which draws 8 amps a CPAP(24Ah/night) and other stuff. One other advantage of golf cart batteries is that the A/hrs is pretty independent of current draw between a 24 hr rating and a 6 hr rating. For most 12V batteries the A/hr rate is for a 24hr constant draw, roughly 4-5A. Once you draw more than 4-5 amps (which isn't hard to do), the Ahr capacity starts to drop pretty fast. So, while they may quote 80AH, if you draw say 15A or so, it may only end up being a 50AH battery. There are true deep discharge only 12V batteries available, Trojan make them, and the probably do a good job as well. One advantage of 6V batteries is that they are slightly larger physically (taller), so you end up with about 10-20% more Amp hrs with two 6V's vs. even the best two 12V. if you do a lot of dry camping try to stay away from batteries that list a CCA (cold cranking amp) or other motor starting spec's, that means they are a combination battery with thinner plates vs. a true deep discharge battery. My dual trojans are going on 7 years and still going strong. FWIW, when we bought our Outback 295RE in June, the std batteries were dual 12V, and I paid extra for dual Trojan T145's instead since we do most of our camping dry.

if you seldom are without shore power, or only go w/o power for a day or night before you can recharge, going with 12V marine battery(s) is probably going to be fine, no reason for the extra cost of something else if you never need it.


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## outback loft (Sep 22, 2008)

I am running 12 volt batteries. One of my batteries has the same if not more amp hours than two 6 volts in parallel. But I also have a few batteries on board connected to a massive inverter and they are capable of running my a/c through the night. If I was using 6 volt batteries I would have over 24 batteries mounted on the trailer, and that much more weight. Each of my deep cycle batteries weighs in at about 70 pounds.


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## Oregon_Camper (Sep 13, 2004)

outback loft said:


> I am running 12 volt batteries. One of my batteries has the same if not more amp hours than two 6 volts in parallel. But I also have a few batteries on board connected to a massive inverter and they are capable of running my a/c through the night. If I was using 6 volt batteries I would have over 24 batteries mounted on the trailer, and that much more weight. *Each of my deep cycle batteries weighs in at about 70 pounds.
> *


*
*

....and how much does each one cost?


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## outback loft (Sep 22, 2008)

Oregon_Camper said:


> I am running 12 volt batteries. One of my batteries has the same if not more amp hours than two 6 volts in parallel. But I also have a few batteries on board connected to a massive inverter and they are capable of running my a/c through the night. If I was using 6 volt batteries I would have over 24 batteries mounted on the trailer, and that much more weight. *Each of my deep cycle batteries weighs in at about 70 pounds.
> *


*
*

....and how much does each one cost?
[/quote]

They were running about $200 a piece at my wholesale cost.


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## wolverine (Mar 5, 2009)

I swithced from one 12 volt battery to two 6 volt batteries this spring. I bought the Sam's club batteries at $75.00 each. So far they have been great. We dry camped a couple of weeks ago and it was in the upper 20's at night and the furnace ran a lot and we watched an entire football game and the kids watched a few movies on our LCD TV. We started with 12.8 volts on my meter and after the weekend we still had 12.4 volts. My camper does not have a 3 stage charger, but I disconnect the batteries anytime I am connected to shore power and I charge the batteries with my deep cycle battery charger that I have at home.


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## Ish (Jun 15, 2010)

wolverine said:


> My camper does not have a 3 stage charger, but I disconnect the batteries anytime I am connected to shore power and I charge the batteries with my deep cycle battery charger that I have at home.


Does anyone know if a 2010 205RS comes with a 3 stage carger or is it just a trickle charger? What I am trying to figure out is what is the best way to top off my 12v battery when dry camping with a generator. Do I just hook the shore power up to the genny and let the camper charge the 12v battery or do I bring my 3 stage deep cycle batter charger along and hook that up to the genny and 12v battery?


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## KTMRacer (Jun 28, 2010)

Ish said:


> My camper does not have a 3 stage charger, but I disconnect the batteries anytime I am connected to shore power and I charge the batteries with my deep cycle battery charger that I have at home.


Does anyone know if a 2010 205RS comes with a 3 stage carger or is it just a trickle charger? What I am trying to figure out is what is the best way to top off my 12v battery when dry camping with a generator. Do I just hook the shore power up to the genny and let the camper charge the 12v battery or do I bring my 3 stage deep cycle batter charger along and hook that up to the genny and 12v battery?
[/quote]

The short answer is yes it probably has one, but no it probably doesn't work. You could be one of the lucky few with a configuration that does work.

The longer answer, if it is like most outbacks, it has a WFCO 8955 55 A three stage charger with boost mode, normal mode and trickle mode. Problem is lots of folks find it hard or impossible to get the charger to automatically go into boost mode. Unlike PD and other units there is no easy way to force it into boost mode either. There are several things contributing to this, first, the wiring from the converter to batteries is probabably #8 or maybe #6 guage, and depending on location could be pretty long. Second, it depends a lot on your battery bank. One or two group 27 will likely never trigger boost mode, 2 6V golf carts, possibly, 4 golf carts a better chance, batteries have to have very low internal resistance and accept lots of current w/o a voltage rise to trigger boost mode. In the 295RE it is over 25' of wire from the charger to the battery. Result is there is to much voltage drop across the wire to get the charger to trigger boost mode. This is because the charger needs the voltage AT THE CHARGER to be below 13.2V to trigger boost mode AFTER the charger turns on at 13.6V. usual result is that the battery voltage plus the voltage across the long length of undersized wire is above 13.2V, and you only get 15-20A charging current. On my 295, I tried going with #4 welding cable, and getting the run as short as possible. (20'), still no luck.

Best thing to do is to discharge the battery(s) to 50% or so and using a clamp on ammeter or very accurate voltmeter measure the current or converter voltage at the converter output to see if it is in boost mode. Current should be 45A plus, voltage at the converter output should be 14V or more. If the voltage stays at 13.6 or current is around 25A or less, nope, boost mode didn't work.

Units with the WFCO8945 (45A charger), seem to be pretty reliable at going into boost mode from web feedback, it's the 8955 that is giving folks fits.

Choices are using your external three stage charger or replacing the innards of the WFCO with a PD 55A replacement, or disconnecting the WFCO and going with a PD or similar 60,70,80A dedicated charger.

do a web search on WFCO boost mode, you'll find plenty of reading!!! Frustrating because IF you can get the WFCO into boost mode it outperforms much larger units. it acts more like current source and will charge at 55+ A until the battery reaches about 80% SOC. PD and other units start at 50A or so and very quickly start tapering the charging current, so that by 80% SOC they are down in the 20A or less range.


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## CamperAndy (Aug 26, 2004)

KTMracer you may be splitting a few too many hairs. Boost mode is not critical for the average user and those that really do care make the changes or effort to make it work. That said spending the time and money for that little extra does not pass the cost to benefit review for most. Look at these examples.

Never dry camp and would not know a group 24 from a T-125 Trojan if it was dropped on their foot. They would even question why they even need 12 vdc since they are always on shore power.

Casual user one or maybe two weekends a year dry camping, most likely warm weather and their biggest concerns will be getting the kids to turn off the lights and the DW will want to know why the hair dryer does not work. They will ask on Monday would it be better to have more batteries or a generator.

That brings us to the next guy that bought a generator and runs it when ever the lights get dim or the DW wants to nuke something. They never really worry because hey they have a generator. Why worry about charge rate.

Then there are the ones the have 4 banks of batteries, solar power and maybe even a wind generator. They track everything and yes they will be interested in reducing the charge time or maybe improving on the life of the batteries by improving the charge efficiency or the sulfidation removal but then they got a bundle in thier system and they will spend a bundle more to make it even more state of the art.

All that said the basic function of charging the batteries is well taken care of by the WFCO converter/chargers that are installed in all Outbacks since about 2005. If it actually fails replace it with another or if you really feel the need get a Progressive Dynamics charger but just because you can force it to go into boost mode does not mean your batteries will last forever or that the average user will notice the extra 15 minutes of use they may or may not get from the battery. Most would be better served by making sure the connections are clean and the auto reset breakers are not corroded and that they actually fully chagre the batteries before they park the trailer in storage for 3 or 4 weeks between trips and when they do park it they disconnect them.


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## KTMRacer (Jun 28, 2010)

CamperAndy said:


> KTMracer you may be splitting a few too many hairs. Boost mode is not critical for the average user and those that really do care make the changes or effort to make it work. That said spending the time and money for that little extra does not pass the cost to benefit review for most. Look at these examples.
> 
> Never dry camp and would not know a group 24 from a T-125 Trojan if it was dropped on their foot. They would even question why they even need 12 vdc since they are always on shore power.
> 
> ...


I agree with what you've said, for the vast majority of campers the standard converter/charge works great, as does a single group 24/27 battery. No reason for them to spend any extra, it's money down the drain. And I do commend outback for using the WFCO charger vs. some of the other cheap chargers they could have used.

There are a minority of us (and from what I've seen, we (I) are a pretty small minority) who do lots of dry camping, and do want or need the ability to quickly recharge battery banks. for example when we camped at Kodachrome Basin state park this fall, there is no electricity and generators are only allowed between noon and 4 pm. Since that's the time you really want to be out site seeing at Bryce etc., it doesn't give much time to charge a battery bank and really messes up a day. It was nice to camp 4 days, then in 4 hour bring my batteries almost to full charge. If we would not have had a charger that would go into bulk mode we wouldn't have been able to do this. at 20amps, takes a long time to get a 400+ AH battery bank charged!

the OP asked about boost mode, and I was assuming, maybe incorrectly, that they asked because they had a need/wanted to get the battery bank charged quickly, and wanted to know if the std converter had bulk mode charging capability. First time we dry camped, I found out the hard way that our WFCO really would not go into bulk mode, and messed up some of our plans, and ended up running the generator much longer and more often than I would have liked to. At least in that case running the generator was an option. I'd hate to find that out at Kodachrome basin. Didn't want the OP to end up going through the same experience.


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## kenngeri (Aug 12, 2010)

I have one real short question concerning batteries and charging while dry camping. I have 2 6 volts and in the NP's generator time is limited, can I use two sources of charging at the same time? With my Honda 2000 can I hook it up the external 30A plug and also use the battery charge cables at the same time?

Ken & Geri
Colorado Springs, CO
2010 210RS
2010 F150 w/max tow


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## luverofpeanuts (Mar 9, 2010)

kenngeri said:


> I have one real short question concerning batteries and charging while dry camping. I have 2 6 volts and in the NP's generator time is limited, can I use two sources of charging at the same time? With my Honda 2000 can I hook it up the external 30A plug and also use the battery charge cables at the same time?


If you're looking to charge your batteries in the most efficient way possible, I think you're best bet will be to use a smart battery charger, plugged into your generator. When I did a little research about using the battery cables with my Honda 3000eu, I found that most information revealed that the direct battery cables only charge at a fixed rate, and relatively low. Whereas the smart battery chargers make more efficient use of the generator A/C power supply to charge up batteries. I'm guessing that a charger like that is probably better/faster than the onboard charger as well. I dunno. I just got the impression that the battery charging cables were more for convenience than efficiency.

I wish I could speak with more authority on the subject, but I've sleuthing for information about generators and power as well. I'm sure a more knowledgeable battery/charging expert can confirm or correct my understanding.


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## Ish (Jun 15, 2010)

KTMRacer said:


> That brings us to the next guy that bought a generator and runs it when ever the lights get dim or the DW wants to nuke something. They never really worry because hey they have a generator. Why worry about charge rate.


The OP asked about boost mode, and I was assuming, maybe incorrectly, that they asked because they had a need/wanted to get the battery bank charged quickly, and wanted to know if the std converter had bulk mode charging capability. First time we dry camped, I found out the hard way that our WFCO really would not go into bulk mode, and messed up some of our plans, and ended up running the generator much longer and more often than I would have liked to. At least in that case running the generator was an option. I'd hate to find that out at Kodachrome basin. Didn't want the OP to end up going through the same experience.
[/quote]

Thanks guys - great info!

CamperAndy - you pegged me. We dry camp 2-3 times a year. I actually borrowed a friends Honda 2000 genny.

However as KTMRacer pointed out - I do worry about runing the genny because of the limited hours available to run it and I don't particulary like the noise. And, I did run into an issue. I was dry camping with some buddies. I topped the battery off before leaving for the trip. The first night at 35 degrees outside was fine. We ran the genny a few hours during the next day and I just assumed (incorrectly) that it would top off my battery. Well, 4 am came and the battery was dead. So, no heat and not being able to run the genny it got a little cold. The next weekend with the family I took my 3 stage battery charger from home and used that off the genny.

One additional question - I think it might be the same as Kenngeri's - If I bring my 3 stage battery charger and hook it directly to the Honda genny, can I also hook the shore power of the TT directly to the other 15amp plug on the genny without unhooking the battery from the camper? I guess that would mean the battery would be getting a charge from 2 sources.


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## kenngeri (Aug 12, 2010)

My question is the same as "Ish" that if I was hooked up to the battery with a charger and hooked up the TT would both sense that the batteries are fully charged?

Ken & Geri
Colorado Springs, CO
2010 210RS
2010 F150 w/max tow


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## Gilligan (Aug 25, 2006)

Unless your two charging sources are absolutely perfectly matched (which would be nearly impossible), they would not share the charging current. Only one source would be supplying it all. The one with the higher voltage would reverse bias the lower one, shutting it off. This would be particularly true, if they have NPN output transistors.

Gilligan


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## Calvin&Hobbes (May 24, 2006)

Gilligan said:


> Unless your two charging sources are absolutely perfectly matched (which would be nearly impossible), they would not share the charging current. Only one source would be supplying it all. The one with the higher voltage would reverse bias the lower one, shutting it off. This would be particularly true, if they have NPN output transistors.
> 
> Gilligan


Wow Gilligan! I didnt realize you were so smart!

so, why did you label my black tank handle with a grey tank label?


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## KTMRacer (Jun 28, 2010)

Ish said:


> That brings us to the next guy that bought a generator and runs it when ever the lights get dim or the DW wants to nuke something. They never really worry because hey they have a generator. Why worry about charge rate.


The OP asked about boost mode, and I was assuming, maybe incorrectly, that they asked because they had a need/wanted to get the battery bank charged quickly, and wanted to know if the std converter had bulk mode charging capability. First time we dry camped, I found out the hard way that our WFCO really would not go into bulk mode, and messed up some of our plans, and ended up running the generator much longer and more often than I would have liked to. At least in that case running the generator was an option. I'd hate to find that out at Kodachrome basin. Didn't want the OP to end up going through the same experience.
[/quote]

Thanks guys - great info!

CamperAndy - you pegged me. We dry camp 2-3 times a year. I actually borrowed a friends Honda 2000 genny.

However as KTMRacer pointed out - I do worry about runing the genny because of the limited hours available to run it and I don't particulary like the noise. And, I did run into an issue. I was dry camping with some buddies. I topped the battery off before leaving for the trip. The first night at 35 degrees outside was fine. We ran the genny a few hours during the next day and I just assumed (incorrectly) that it would top off my battery. Well, 4 am came and the battery was dead. So, no heat and not being able to run the genny it got a little cold. The next weekend with the family I took my 3 stage battery charger from home and used that off the genny.

One additional question - I think it might be the same as Kenngeri's - If I bring my 3 stage battery charger and hook it directly to the Honda genny, can I also hook the shore power of the TT directly to the other 15amp plug on the genny without unhooking the battery from the camper? I guess that would mean the battery would be getting a charge from 2 sources.
[/quote]

WFCO charger is on the same circuit as the non GFI outlets. I'd turn off that breaker to only charge from the other charger if I was also plugged into shore power to avoid any issues. What I did, since I wanted to turn off the charger when running the microwave off the generator, is to connect the converter on it's on breaker, by adding an additional 15A breaker in the panel and leave the non GFI outlets on there own circuit.


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## Gilligan (Aug 25, 2006)

Calvin&Hobbes said:


> ...so, why did you label my black tank handle with a grey tank label?


The labels are put on at the dealer. HA! Thought you could hang that one on me!









Gilligan


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## twincam (Jan 11, 2010)

you will be glad you switched, 6 volt is the best!! ive tried about every battery made and i still come back to 6 volt systems. More money but far more runtime, thats why they are used on industrial equiptment, golfcarts etc. They do take longer to charge, its better to charge them individually with a 6 volt charger or at least a real good 12 volt charger. The trailer convertor charger is not going to ever charge them to capacity. Read up on them , they take little more care but are far better. imho


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## Ish (Jun 15, 2010)

KTMRacer said:


> WFCO charger is on the same circuit as the non GFI outlets. I'd turn off that breaker to only charge from the other charger if I was also plugged into shore power to avoid any issues. What I did, since I wanted to turn off the charger when running the microwave off the generator, is to connect the converter on it's on breaker, by adding an additional 15A breaker in the panel and leave the non GFI outlets on there own circuit.


Great idea! I have to put this on my to do list!


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