Two 6 volt vs two 12 volt run time

FWIW, my front storage battery/etc compartment that has the 5 batteries in it is approx. 22" X 38" X 96" (8 feet) and is very well OEM vented beside the Tupperware battery container with the vent thru the floor I'd added. Nope, I do not worry about a battery explosion from gassing.

Again, the venting of batteries is not all about you and your situation or about me and my situation.
I only mention gassing of hydrogen from battery charging in that it is necessary and hydrogen is lighter than air.

If you need examples, look at what is being made for venting battery boxes: vented battery box

Perhaps an explosive concentration could occur over a long time in a small sealed compartment with several batteries off gassing and that could be dangerous. That would take a lot of off gassing even in a small compartment and exploding batteries or gasses in RV is very seldom a cause of an explosion as I have researched it.

Can it happen? Sure but very rare but still wise to pay attention to the possibility even if it is so rare. Hard to trust some of the junk that some manufacturers are making today, so always check yours out before adding a battery bank since it's you who is making the alterations not the manufacturer. Of course, there likely could be some people that would allow this type of sealing a battery space to occur and have a spark or flame source exist inside but it IS also widely known that any battery compartment must have some adequate ventilation. I can't say I have ever see an OEM RV or even a boat built with totally sealed battery compartments as all either have bottom floor grates/screens, or door louvers, or tube vents, or the bottom casing around the door molding sealing edge cut away for venting, etc.

Boats usually use blowers or have incoming pointed forward air scoops on one side and rear facing air scoop vents on the other side for that venturi action again whether the blower is running or not and works even when docked. Extremely rare to have a battery blow in a boat and where we live is a boating haven and heaven with 10's of thousands or boats and dozens of large marinas about all the boats have one or a lot more batteries in their bilge. Same with the compartments the propane tanks are housed in when in a doored compartment. Explosions from fuel leaks yes, but never heard of one from battery gassing in my over 75 years. My own 10-1/2 year older brother owned one of the large marina's here before selling and is now long retired like me. He lives in Florida now.

FWIW, my front storage battery/etc compartment that has the 5 batteries in it is approx. 22" X 38" X 96" (8 feet) and is very well OEM vented beside the Tupperware battery container with the vent thru the floor I'd added. Nope, I do not worry about a battery explosion from gassing.

travelnutz wrote:
My off gassing only goes out the bottom 1/2" dia plastic water pipe elbow to under the trailers!

Not to belabor this but in the interest of safety for others, you are wrong.

Hydrogen gas is colorless and odorless. Sulfur dioxide does have a smell and is somewhat like rotten eggs. Both gases are produced from a battery when charging.

Sulfur dioxide is heavier than air when first produced. Hydrogen is lighter than air. Sulfur dioxide is not flammable. Hydrogen is flammable, it is explosive when mixed with air in the right quantity.

tinner12002 wrote:
... how hard would it be to have say one outlet in the kitchen set up to run a coffee maker on an inverter so I wouldn't have to start the gen...and how big an inverter would a person need for such a setup...2000watt?

I installed a 1000 watt PSW inverter in our trailer's front pass through cargo compartment and wired the outputs to dedicated receptacles - one outside the trailer for powering a fan on really hot days sitting under the awning and 3 duplex receptacles inside, one of each side of the bed and a third at the galley where I can power a toaster or coffee maker. Since we only use this periodically when we're without shore power for one reason or another I run with just one G27 battery - for powering light loads such as a fan that's more than enough but when the inverter is under heavy load from the toaster or coffee maker load supporting it with the truck prevents excessive voltage drop which would otherwise cause the inverter to alarm & shut down. A dozen pics start here.

tinner12002, etc

Most simple drip coffee makers draw around 900 to 950 watts so a 1500 watt inverter will do the job fine but you must have enough battery amperage available and large enough connecting wires. On the bottom usually of all AC or DC current items it will tell the amps or watts max the item will take. Very important! Never have an electrical circuit that can handle less that what your draw will be and I prefer a 10%-15% safety margin so fuses are not likely to blow if the voltage drops as with lower voltage the amps draw will increase. 117v AC is the normal recommended and 110v when item running is a min to me for longer item life. Others may think a little lower voltage is ok but that is up to them. Lower voltage makes motors run hotter and burn out faster and heater circuits will have less output.

Keep 12V DC wires as short as possible like 4 feet or less to the inverter and go to the next larger wire for up to 10 feet. 12v DC has a lot of line loss resistance with long leads. That means mount the inverter as close to the batteries as possible for best results. I'd recommend a min of 200AH of battery/batteries min for a 1500 watt inverter. 300 for a 2000 watt and 400 for a 2500 watt as a min. Only you knows what you may use the inverter for so you make the call.

Once thru the inverter and changed to 110v AC, with 50 foot length there's very little voltage loss.

If you have a basement area under your inside floor, it's quite easy to fish a wire thru and come up under where you want the outlet like next to a lower cabinet door etc so you can mount things. In 2 of our RV's in the past, I simply ran a #14 ga 3 wire outdoor rated extension cord and left the female end inside the cabinet and just opened the door and plugged in what I wanted to and closed the door as much as possible without pinching the cord. Hey, it's a temporary hookup and then unplug and close the door.

I don't have any idea how you lower area is constructed or where your batteries are in relation to your kitchen so you must figure out what will be the easiest way. It only takes about an hour to install a circuit like mentioned. If you have to drill or cut a hole for the new wire or cord, be sure to reseal around the wire to prevent air leaks, mice holes, or the new wire from rubbing and chaffing on the cot or drilled hole edges. If you purchase an inverter with a remote on/off switch or can plug in a remote switch, the inverter can be in a storage compartment and you operate it from inside the RV.

On a side note:

A poster said the fumes from the batteries is lighter than air and goes up. Not to argue with him but I have put a very heavy load on my batteries thru the inverter for about 20 minutes until the batteries got warm to the touch and got under the vent tube under the trailer and smelled the off gassing coming from the tube. then opened the compartment and there was NO smell in there so I know the gasses went out the vent tube. Did the same smell test again after recharging the battery bank until full charge and had the very same results. My off gassing only goes out the bottom 1/2" dia plastic water pipe elbow to under the trailers!

Added to this is elbow on the bottom threaded end of the elbow on the outside under the trailer, I screwed on another elbow to it and pointed the open end toward the rear of the RV so it acts like a venturi suction tube like in a carburetor and thus when driving or a wind blowing sucks the air thru the compartment OEM vents and thru the battery box and pulls any fumes out. Never had any fumes in the compartment or and corrosion of any kind in there. The RV 65 amp converter, the 2500 watt inverter, the OEM 12 volt system fuses, and the 5 big lead acid deep cycle batteries are in that compartment plus our PP grill and some other smaller things. Using common sense, and it's a big help, for doing things right!

travelnutz wrote:
Atlee,

Hope this doesn't bore you as it's long but accurate.

My true deep cycle 12 volt lead acid batteries all came from Meijer but you don't have them there as they are in 7 states in the Midwest. A very upscale Walmart type store but usually larger and carries a lot more made in the USA goods but has the same prices as Walmart. Family owned and based/headquartered in Grand Rapids, MI. Over 200 stores. I'd wait until they were on sale and then used my 15% off all goods in one purchase coupons we'd get each month as seniors with a Meijer credit card. I'd buy 5 to 10 of the batteries at a time and never paid over $88. for each anter the discounts. the batteries were made by Johnson Controls Battery Divison headquartered in Milwaukee, WS.

Now Meijer carries Exide batteries instead of Johnson Controls and they are group 31, deep cycle marine 12 volt batteries and have the very same spec label wording as the Johnson Controls batteries. 130 Ah with a 225 minutes at 23 amp draw. I have seen zero difference between the 2 type of batteries in useage or performance life. Been keeping both types of batteries in the RV's banks for 8-10 years and then replacing them. They still function OK and I have been using the old batteries in my boats and for my trolling motors and only one so far had failed in the last 0ver 30 years of using these batteries.

The 5 group 31 deep cycle marine batteries presently in our 29' Carriage Carrilite 5th wheel were purchased in Sept 2010 as that is what the sticker on them says and I will probably be replacing them in 2019 as they are 7 years old now. In the Carriage Carrilite, we use the 2500 watt inverter which I had installed 2 additional 15 amd AC circuits from the inverter mounted in the front storage area with a remote switch on the foot vertical wood face of the bed.

One circuit goes to the additional installed 3 duplex outlets in the bedroom, bathroom, and the living room. The other circuit goes to the kitchen installed additional duplex under the refrigerator in the panel and to one close to the dining table in the slide out. It's in the inside bottom area of a storage cabinet just above the floor. Open the cabinet door and plug in the extension cord that comes from the wall behind the table and we have AC power for our laptops.

The kitchen inverter duplex outlet has a small 1/4' dia green neon light glued in and wired in so we know when the inverter is turned on. That outlet is for the coffee maker cord, toaster cord, and the microwave which has a patch cord from a switch in the upper cabinet where the microwave is plugged in. Open the cabinet, flip the switch to inverter power, pullout the end of the patch cord, and use the microwave when off the grid and no need to start the generator.

Lots of time with our 2 laptops on as we have a MIFI Jetpack for WIFI nd change data plan from 6GB to unlimited if and when needed with Verizon. We never use a hair dryer off the inverter as that is on for a longer time and like a direct short. Silent 110 AC power and no need to start up a noise making generator bright and early in the morning.

That in an expanded nutshell is what we have and how we use our battery bank.

BTW, there's 2 more of the same batteries in the drivers side ahead of the rear wheel well and if I attach the 2 #2 gauge welder cables to the marine barrel switch wingnut stud block, I now have 7 group 31 deep cycle batteries for the 5th wheel and dual alternators in the diesel truck to recharge the 7 batteries real fast it we aren't going to hit the road that day etc. Of course I have another option also, start up the Honda EU 2000 that's on the back of the 5th wheel and recharge the batteries that way. I love versatility and that's the way I design and make things like any good engineer would, long retired or not!

The 2 big batteries in the truck also connect to the same size battery in our Lance TC so I have 3 big 12 Volt deep cycle batteries to power the Lance and the 1500 watt inverter that's mounted inside when it's on the truck. More versatility!

Whew!! This stuff is way over my head! But since you brought it up, how hard would it be to have say one outlet in the kitchen set up to run a coffee maker on an inverter so I wouldn't have to start the gen...and how big an inverter would a person need for such a setup...2000watt? Sorry not trying to heist the thread but looks like its gotten a little off of the orig question anyway

Last I checked Optima and Lifeline were about the same capacity per $$.
Capacity per square inch the Lifeline wins easily if you have limited space.

Atlee wrote:
Unfortunately this is another not true deep cycle 12v battery. It is a marine/deep cycle battery, which is a hybrid.

If I get a pair of 12v deep cycle batteries, I want them to be the same type battery construction as 6v golf cart batteries and I want them to be in the same general price range for the about the same # of amp hours.

marcsbigfoot20b27 wrote:
Sams club group 31 AGM deep cycle made in USA by East Penn / Deka for $179
Shows the specs also.

https://www.samsclub.com/sams/duracell-agm-deep-cycle-marine-and-rv-battery-group-size-31dtmagm/prod3590232.ip

Maybe it's just verbiage..... They don't call this one dual service they call it heavy duty deep cycle.
http://www.eastpennmanufacturing.com/wp-content/uploads/Intimidator-Marine-Flyer-1741.pdf

Atlee wrote:
If I get a pair of 12v deep cycle batteries, I want them to be the same type battery construction as 6v golf cart batteries and I want them to be in the same general price range for the about the same # of amp hours.

You hit the nail right on the head!

For instance, the 12V true deep cycle Fullriver AGM batteries I showed in my link were an "expensive" way to get 230 amp hours capacity out of two of them in parallel.

BUT, I'm betting that 6V true deep cycle AGM (not Sam's Club/Walmart/Etc. golf cart liquid acid) batteries would also be an "expensive" way in order to get 230 amp hours capacity out of two of them in series.

Being careful to do apples-to-apples comparisons are what it takes to really be sure of what you want verus what you might be getting.

The bottom line is - if you want to get the most bang for the buck with no consideration of the advantages of AGM - go with Sam's Club/Walmart/Etc. 6V golf cart liquid acid batteries. 12V TRUE DEEP CYCLE batteries - whether it be liquid acid or AGM - will always be more expensive versus amp hours of capacity.

Unfortunately this is another not true deep cycle 12v battery. It is a marine/deep cycle battery, which is a hybrid.

If I get a pair of 12v deep cycle batteries, I want them to be the same type battery construction as 6v golf cart batteries and I want them to be in the same general price range for the about the same # of amp hours.

marcsbigfoot20b27 wrote:
Sams club group 31 AGM deep cycle made in USA by East Penn / Deka for $179
Shows the specs also.

https://www.samsclub.com/sams/duracell-agm-deep-cycle-marine-and-rv-battery-group-size-31dtmagm/prod3590232.ip