Switching from 12 volt to 6 volt batteries

[GravelRider]

After our third time out dry camping with our new travel trailer, we started running into battery bank issues. Our first two times out, we had no issues at all with running down our battery bank overnight while dry camping. We added a television to the camper (which we fell asleep watching! Doh!) and used heat for the first time overnight and ended up in the morning with our voltage reading at 11.4 volts. To be fair, our 12 volt fridge was running at the time, so I'd imagine actual voltage was probably 11.6 or so, but still too low for my tastes, and for good battery longevity. Granted, better discipline would have avoided this, but it got me thinking about adding some more capacity. And yes, I know, better discipline is the right answer here... But I like overkill... lol

I have two 12 volt 81 Ah batteries (which I thought were 100 Ah when I bought it... as the dealer said the 'upgraded' batteries were around 100 Ah) for a total bank of 162 Ah. I had looked into adding two more 12 volt batteries in the 75-100 Ah range, but that ends up being a lot of extra weight at the front of the trailer, and finding space for them would be an issue. So, I'm now thinking of swapping out the two 12 volt batteries for two 6 volt batteries wired in series. This would give me 450 Ah, which would likely be far more than I would ever need, and I would probably never discharge near 50%. ****EDIT, nope! 225 Ah!

I'm looking at this battery and this box, which would only add about 50 extra pounds.

Anyhow, besides the battery boxes and series wiring, would I need to do anything else? Like add a different converter or anything?

FYI, my trailer is a 2021 Indian River 22MKSE with a small 50 watt solar panel factory installed (which I really only use to keep the batteries trickle charged when stored).

[Vintage465]

crosscheck wrote:

bpounds wrote:

crosscheck wrote:
One of the main reasons I chose a Danfos compressor style 12V fridge /freezer was because the they are a favourite of the ultimate boondockers which are yachters....snip

Using 12VDC is by far the least efficient way to generate heat, out of the 3 utilities common on RVs.

That's not to say it isn't appropriate in some situations. You mentioned one.

If you've got enough solar and battery bank to support it, more power to you. I've noticed there isn't much shade over sailboats.

I have seen a 12vdc fridge run our truck battery down during a single overnight stop at a motel. GM truck, which did not isolate the trailer from the starting battery. So it depleted the trailer battery and the truck battery. I wasn't the owner, but I was a participant, and it was my AAA card that got us back on the road that morning.

"Compressor Refrigerators
They use a process that compresses refrigerant to draw hot air out of the food compartment and vent it out the back or top of the fridge. They are highly efficient compared to absorption refrigerators." These are not my words but taken from a technical article regarding RV's. Compressor fridges do not use heat to make cold like absorption fridges do, that is why they are more efficient in energy use. If you are set up for high efficient compressor fridges, they work much better than absorption fridges. Just read all of the posts by big rigs who are turfing their Norcold units for compressor fridges.

One last thought, as most modern houses/apartments/businesses have natural gas and could have absorbtion appliances for cooling/freezing, why is compressor technology used in fridge/ freezers in 100% of domestic and industrial applications throughout the modern world?

Check out our blog when we had our previous rv an Outfitter TC for 5 years. You will see our camping style is "dry" with very few times using genny or shore power and our compressor fridge was never a problem regarding running down the batteries.

Dave

Regarding your "one last thought". Yes it is true that most if not all modern houses use compressor fridges and freezers. And they are hooked to the grid and barring and outage, they have limitless non stop electricity. Obviously in an RV we don't have limitless electricity....but 14 gallons of propane will run my Norcold for better than thirty days........that's almost limitless....with a real small amount of planning. 12v compressor fridges are better than ever, but for real boon docking some regeneration homework needs to be done to keep one of those in check.

[pianotuna]

Off the grid for any sensible person would include as much solar as is possible. A one time cost versus a noisy, smelly, dangerous generator.

I rue the day I caved in and purchased a generator.

[StirCrazy]

crosscheck wrote:

One of the main reasons I chose a Danfos compressor style 12V fridge /freezer was because the they are a favourite of the ultimate boondockers which are yachters. They can't use propane fridges because propane is heavier than air and could sink to the lower decks if there was a leak and could cause an explosion.


Dave

I think the real reason they use them is like you said they cant use propane and that they have built un generators so the power worry isnt a factor. I know severy "Yachters" that if not for the saftey issue would gladly use propane appliances over the 12V stuff so they could run there genny less.

Steve

[pianotuna]

Huntindog wrote:
Do you think those fans would do as good a job circulating heated air thru the underbelly as the furnace fan?

I agree on not using a non vented heater... Even when not planning to sleep. Sometimes those heaters can make one sleepy.
I do use the generator though. It is 75' away, usually behind a tree/fallen log etc.

Hi Huntindog,

All I can tell you is they were effective in my class C at -37 C (-34 f).

I was having freeze ups while driving--the furnace was on, but the heat from the cab prevented it from cycling. They do not move nearly as much air as the furnace fan. I've not had a freeze up since 2010.

By unvented heating device, I have, on occasion, when street parking where I was in a convention all day long, run the burners on the stove top at low levels. It was in Calgary, and I had no access to shore power. I did leave the furnace active, but at the lowest possible setting. There was a tremendous blizzard. I would return "home", start the generator, turn up the furnace, turn on electric heaters and run the stove burners flat out. After 2 hours I'd make my supper. Then I'd drive to the nearest gas station, refill the generator, and refill the propane tank. As soon as I was finished fueling, I'd restart the generator. Then back on the streets for another night. I had a Kipor 3000 Ti inverter generator, with electric start. About 10 pm, I'd stop the generator, refuel it, turn on my smallest inverter, and use a heating pad in the bed.

I had an analog cell phone and a dial up isp with a toll free number. The laptop was connect to the cell phone by a device that provided a dial tone. My connection speed was 1/4 regular dial up--but it was good enough to do email--and even streaming audio from the BBC. Web sites were not nearly so data intensive in those days. The cell phone had unlimited minutes after 6 p.m.

75 feet would make it safe to run a generator. Unfortunately, after having one stolen, my generator is bolted in place, and protected by a steel cage. I know it would only slow someone down.

[Huntindog]

pianotuna wrote:

Huntindog wrote:
Probably with some creative modding it could be made to work... BUT it probably would be a waste of time. The reason for a CAT heater is to eliminate the draw from the fan. Installing a fan that would move enough air to make a difference would put you back where you started from.

My twindow fans draw a scant 27 watts and solved water line freeze ups. I used them to replace the return air grill for the furnace. I operate them using a mechanical thermostat kept near the water pump.

I won't use a non vented combustion heater, nor a generator when I plan to be sleeping.

Do you think those fans would do as good a job circulating heated air thru the underbelly as the furnace fan?

I agree on not using a non vented heater... Even when not planning to sleep. Sometimes those heaters can make one sleepy.
I do use the generator though. It is 75' away, usually behind a tree/fallen log etc.I do not try to conserve energy when cold weather camping. The generator never shuts off.

[philh]

GravelRider wrote:
I installed the battery monitor today, so I'll be able to get a much better picture of how much battery I'm using and how much each item is drawing.

What model is that battery monitor?

[Huntindog]

DP

[pianotuna]

Huntindog wrote:
Probably with some creative modding it could be made to work... BUT it probably would be a waste of time. The reason for a CAT heater is to eliminate the draw from the fan. Installing a fan that would move enough air to make a difference would put you back where you started from.

My twindow fans draw a scant 27 watts and solved water line freeze ups. I used them to replace the return air grill for the furnace. I operate them using a mechanical thermostat kept near the water pump.

I won't use a non vented combustion heater, nor a generator when I plan to be sleeping.

[Huntindog]

CavemanCharlie wrote:

Vintage465 wrote:

crosscheck wrote:

Vintage465 wrote:

crosscheck wrote:

bpounds wrote:
Couple things to add,

That 12v fridge is bad news for boondocking. They are very inefficient. Normally only find those in popup style rigs. But, I guess you're stuck with it. Get more battery.

I like the Vmax line of 6vdc. And with those AGM, you do not need to put them in a battery box. They are safe in any orientation. That might allow you to get even more than 2 of them, but you do need pairs. Unless you look at the Vmax 12vdc AGM. I don't have the 12v, but I would trust the name.

The cheap club store batteries will need to be in a box, and you'll likely end up replacing them sooner. Depending on how you maintain them. Might or might not be worth the savings to you.

One of the main reasons I chose a Danfos compressor style 12V fridge /freezer was because the they are a favourite of the ultimate boondockers which are yachters. They can't use propane fridges because propane is heavier than air and could sink to the lower decks if there was a leak and could cause an explosion.
Our camping style is 98% dry/boondock camping. For 5 years, we camped with a 7.5cuft NovaKool fridge/freezer which when cycling used 4.4A. They are more efficient than absorption fridges using 1/3 less energy. They cool much quicker, for the same outer dimensions, have 1/3 more volume, keep more consistant temperatures in hot ambient temperatures and are not a fire hazard. We almost never needed our 2000W genny as we had 4 6V AGM batteries and lots of solar.

People who use the term"12V fridges are bad news for boondocking" have never had this kind of fridge. They are becoming much more popular for so many reasons as long as you figure in more electrical capacity(batteries, solar) if you don't want to run your genny.

I have a 6 cuft absorption fridge in my TT which came with the new unit. If it gives up the ghost down the line, a 9 cuft NovaKool will fit exactly in the same opening and as I already have plenty of solar and 4 6V GC-2 batteries and more room for extra solar, this is the route I will go.

Dave

That does sound like an efficient 12v fridge. My concern as a boon docker is I hate.........did I say hate?.... Generators. I'll do most anything not to use a generator. And I like camping year round. That include weather that gets down in the teens. I'd need enough battery to run my furnace to heat the the belly of the coach to keep the tanks warm enough. I can keep up with my furnace pretty easily with my solar, but I think if you tagged another fairly high draw unit on the 4-6v's it'd get critical. Bottom line is you really have to prioritize your usage choice. I want a furnace, a C-pap, no genny and winter. Prolly nixes the 12v fridge...for my boon docking needs.

Howdy, to another Creekside owner. Another neat plus for compressor fridges is that they can be operational without problems out of level for long periods of time.( Again, think of yachts).
No question, the NovaKool was the largest single draw of battery power bar none.So if you had to choose, get rid of the OEM heater fan and put in a Cat heater. I have no experience with these but some say they work well.
My absorption fridge works fine but I would replace it in a heart beat if it quit.

Dave

Problem with the CAT heater will not heat the belly in real cold weather. I personally am big fan of propane fridges. I don't see any reason to use anything different. I've also found, as I get older, that there are an alarming number of people that really don't care what my opinion is! Everyone will use what they need that fits their use needs.

Sorry to jump in on the middle of your conversation. Could a person use a CAT heater and a 12 volt fan to push heat into the underbelly ? I've often wonder d about this.

I too love my propane fridge that I have in my 1993 Travel Trailer and I have no problems with it cooling.

My brother has a 2018 5th wheel and the propane fridge that he has will not keep food cool when he is traveling down the road, or in days when the outside heat is high. I think the newer ones are not built as well and are giving the whole industry a bad reputation.

Probably with some creative modding it could be made to work... BUT it probably would be a waste of time. The reason for a CAT heater is to eliminate the draw from the fan. Installing a fan that would move enough air to make a difference would put you back where you started from.

[Huntindog]

GravelRider wrote:
I installed the battery monitor today, so I'll be able to get a much better picture of how much battery I'm using and how much each item is drawing.

I have a 18 CF propane fridge that works great.
Are there any comparable 12V fridges? If so, how much power do they use?

[Boon_Docker]

The original trailer wires will be just fine with the new batteries.

[GrederFagot]

pianotuna wrote:
Here is some more detailed information on SiO2 batteries:

***Link Removed***

I just switched over to (2) 6 volt batteries for my trailer from original 12 volt that cam with it. They are correctly wired in a series to supply 12 volts to the trailer. Question is, Do I need to install thicker gauge ground and positive wires to the trailer? When I purchased the batteries, they gave my a thicker jumper than the original ones.

[GrederFagot]

i

[crosscheck]

bpounds wrote:
I have agree with Vintage465. My propane ain't broke, and it don't need fixing. It is perfect for boondocking.

I get it though. Absorption fridges are kind of a pain at times, for some people, and the urge to go with a residential fridge is strong. All kinds of ways of justifying a residential unit in an RV have been posted. Now that solar and lots of battery are all the rage, some have lost interest in efficient off-grid practices. Just throw juice at whatever inconvenience comes along. Okay as long as the weather stays clear and sunny.

Whether it runs through an inverter, or directly on 12v battery, a residential fridge is what it is.

We are out camping without internet in the southern Canadian Rockies. Made it to town and have a few comments on your post.
1) Residential fridges and what the OP is talking about are quite different.
2) We have the option of having propane or all electric 12 v fridges in our RV's when camping. You choose to ignore the positives of all electric fridges even though many including myself have successfully dry camped for 5 years with one and you have never had any experience except for the fact that you have enjoyed residential fridges at home for the last many, many years.
3)Because 12 v fridges are your biggest draw of electricity from your batteries, you just naturally look for ways to conserve when boondocking.
4) Solar and batteries are the rage because they work.I am on a 2 month staycation dry camping in BC and in the end, no Genny or shore power, all because of solar/ batteries.

Dave