6V versus 12V Batteries

[ColoradoRick]

When we did our PDI with our Rockwood, the technician said he really likes to go dry camping and had swapped out his 12-volt RV batteries for two 6-volt batteries because they last longer. (He said you just have to wire them different.) He suggested that we do the same if we intend to do a lot of dry camping.

I'm an engineer, not an electrician so my questions are...

1) Since it appears two 6-volts are better than two 12-volts, why doesn't the RV already have that? (I checked prices and they 6-volts do run about $70 more.) Is the cost the reason?

2) Have any of you swapped out for 6 volters? If so, how much of an improvement did you get?

[davel1971]

a smaller percentage of people dry camp, so I'm sure cost is the main reason. Not that you can't dry camp with 1 12 volt, but a pair of 6s will provide power for a longer period of time.

[Ham_Bone]

Yes cost is the reason.

Both of my trailers have had 6 volt batteries installed. For your effort you will get 220 amp hours per pair of 6 volt batteries, a huge increase over any stock configuration as it comes from the dealer. In addition, a 6 volt battery is over-built with huge, thick plates. They are insanely robust and designed to be discharged and recharged hundreds of times. It's not unusual to get 8 years of use out of a pair that has been properly maintained, providing you do not make a habit of discharging them more then 50%. But, having said all that, if you are not willing to replace your WFCO converter/charger with a higher quality one you are wasting your time and money. WFCO's are heaps better than they once were but, in my opinion, they aren't there yet in terms of properly maintaining a battery bank, especially a battery bank you are depending on when you are going without shore power.

[acadianbob]

Originally Posted by davel1971

a smaller percentage of people dry camp, so I'm sure cost is the main reason. Not that you can't dry camp with 1 12 volt, but a pair of 6s will provide power for a longer period of time.

I think this is true. It is also true that, once, depleted, two 6 volts will take longer to recharge.

I personally do not see the advantage unless that extra period of time completes your dry camping experience. If not, then you are running a generator anyway; and for a longer period of time to recharge.

I just use one Group 30 Trojan 12 volt and a Honda EU2000i for recharging. This strategy works great for us. We run the Honda briefly at the beginning of the day so that DW can run her hair dryer and we can use the microwave for breakfast prep. Then we run it for about an hour at dinner time. We've gone for 2 weeks dry camping using this strategy with no problems.

So, as I see it, 12 volt means shorter charge times buy more frequent; 6 volt means longer charge times but less frequent than 12 volt. Take your pick. 12 volt is cheaper, simpler, lighter IMO.

We do wind up having to move because we run out of holding tank capacity.

[acadianbob]

Originally Posted by Ham_Bone

But, having said all that, if you are not willing to replace your WFCO converter/charger with a higher quality one you are wasting your time and money. WFCO's are heaps better than they once were but, in my opinion, they aren't there yet in terms of properly maintaining a battery bank, especially a battery bank you are depending on when you are going without shore power.

Yes. My WFCO has never seen anything over 13.6 volts of charge; ever. Batteries need more than that. Also, the WFCO does nothing to anti-sulfate. I use a good smart charger to give the battery the voltage it needs. And then I maintain it with a Battery Minder and to get anti-sulfation. I get 8 to 10 years out of my batteries; RV, lawn mower, tractors, motorcycle; you name it.

To the best of my knowledge, the 3 stage WFCO really is nothing more than a dumb trickle charger; a constant 13.2 volts.

[Ham_Bone]

Originally Posted by acadianbob

I think this is true. It is also true that, once, depleted, two 6 volts will take longer to recharge.

I personally do not see the advantage unless that extra period of time completes your dry camping experience. If not, then you are running a generator anyway; and for a longer period of time to recharge.

When boondocking, one doesn't go for a daily, 100% recharge of the battery bank. I rarely deplete my bank below 75% and rarely recharge it more than 90%. As you probably know, that last 10% takes forever. But to get back to 90% isn't a long term proposition. My converter allows me to override the programming and force it into the bulk mode charge, thus reducing generator run time.

[SKnight]

I went from the factory single 12V, to four 12V in parallel pairs to four 6V in a series parallel arrangement.

I went from 190AH per pair to 230AH per pair, 380AH total to 460AH total. During my dry trip I had the fridge running, a few LED lights at night, an inverter with my phone, iPad and my cpap plugged in at night and would usually watch a movie at night with the TV running on the inverter.

It would take my generator running for about two hours to bring the batteries up to the point that the converter would reach float, 13.15V to 13.2V. So I'd get up, fire the generator, make breakfast and fiddle around washing dishes and whatnot.

Thus far I'm really impressed with my 6V arrangement, I tried multiple 12V before with my TT and I couldn't get close to that performance.

[rana]

Ham_Bone and AcadianBob hit it on the head about the stock converter. You'll still see a big increase in capacity going with 6v'rs, but really cutting off their legs if you don't upgrade your converter/charger. as well. Preferably programmable with remote sensor. If you really want to go all out, it wouldn't be a bad idea to do a little research on wire gauge ampacity to ensure your lines are up to the task.

As one poster mentioned.. most stock converter/chargers put out 14.4 (which is barely adequate for a decent 6v to begin with) but it's pretty rare to see anywhere near that actually getting to your batteries. 13.8ish is probably fairly common, but I've seen some folks only getting 12.7 at the battery terminals... then complain their brand new 6v's won't hold a charge. :-)

[Witch Doctor]

Originally Posted by Ham_Bone

Yes cost is the reason.

Both of my trailers have had 6 volt batteries installed. For your effort you will get 220 amp hours per pair of 6 volt batteries, a huge increase over any stock configuration as it comes from the dealer. In addition, a 6 volt battery is over-built with huge, thick plates. They are insanely robust and designed to be discharged and recharged hundreds of times. It's not unusual to get 8 years of use out of a pair that has been properly maintained, providing you do not make a habit of discharging them more then 50%. But, having said all that, if you are not willing to replace your WFCO converter/charger with a higher quality one you are wasting your time and money. WFCO's are heaps better than they once were but, in my opinion, they aren't there yet in terms of properly maintaining a battery bank, especially a battery bank you are depending on when you are going without shore power.

X'2 if it is that important and increase your convertor from 50 amp to 70 amp less charge time.

[Obrieri]

I updated from 2 - 12 v to 2- 6 v GC batteries but we dry camp mostly so the addition of a 123 watt solar system completed system. I never see the battery charge go below 50 percent. More than satisfied. I live in Newfoundland & the 2 - 6 volt batteries cost about $100-125 more than 2 brand name 12 v's
I use my Honda EU 2000 only for microwave, toaster, hair dryer. LED bulbs are next on the list for upgrades.

[mpotapa]

Originally Posted by Obrieri

I updated from 2 - 12 v to 2- 6 v GC batteries but we dry camp mostly so the addition of a 123 watt solar system completed system. I never see the battery charge go below 50 percent. More than satisfied. I live in Newfoundland & the 2 - 6 volt batteries cost about $100-125 more than 2 brand name 12 v's
I use my Honda EU 2000 only for microwave, toaster, hair dryer. LED bulbs are next on the list for upgrades.

I thought about switching to 6vs but I think I'll just carry a spare 12v battery in my truck and just keep it maintained. I bring my voltage tester and test them daily. What will 50% of a 12v battery read on my meter? 12.06?


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[Ham_Bone]

Originally Posted by mpotapa

I thought about switching to 6vs but I think I'll just carry a spare 12v battery in my truck and just keep it maintained. I bring my voltage tester and test them daily. What will 50% of a 12v battery read on my meter? 12.06?


Sent from my iPad using Tapatalk HD

Measuring the remaining capacity in a battery bank cannot be done with any useful degree of accuracy using voltage readings. Battery manufactures recommend you let the battery achieve equilibrium by resting 24 hours before observing the voltage. Resting means zero charges in and zero charges out. There are those people who claim waiting 4 hours is enough. Either way is impractical to a boondocker. Then there is the matter of battery temperatures. Higher temperature raises the open-circuit voltage, a lower temperature lowers it, throwing another curve into the game.

Coulomb counting is only practical method to determine your bat bank status.

[RKR]

Wow , what an education on batteries. Thanks for sharing


Sent from my high tech gadget

[SKnight]

Originally Posted by mpotapa

I thought about switching to 6vs but I think I'll just carry a spare 12v battery in my truck and just keep it maintained. I bring my voltage tester and test them daily. What will 50% of a 12v battery read on my meter? 12.06?


Sent from my iPad using Tapatalk HD

Yep, when the battery final result is a 12V configuration the standard numbers apply. 12.65V is 100%, 12.06V is 50%, etc.