Use 24v Batteries to run 12v System... Possible?

[furyous68]

Sorry for the long post....

Hi everyone. I am new here. I am an RV greenhorn... don't even own one yet. But, we're in the market & the biggest thing I want out of it is to be as self-sufficient as possible. The very first thing I will be doing (besides checking over the engine, trans, rearend, and general health of the coach) is updating the charging system with a solar system. I do not want to run the generator unless absolutely necessary. I HATE when other campers run their generators for 12 hours out of the day, & I refuse to be one of them.

I'm looking at a 12v/24v solar system w/ a 60A MPPT controller. I know I could use 1 or 2 12v AGM batteries. BUT... I'm really interested in seeing if it's possible to run the RV's 12v system off of 1 or 2 24v batteries. If so, I could use 1 or 2 smaller batteries & due to you only needing to pull 1/2 the amps @ 24v's. I assume you would need a step-down converter between the 24v batteries & the 12v converter in the coach... right?

Somebody school me!

[Almot]

furyous68 wrote:

I also notice that 6v batteries typically have significantly more AH than 12v.

I see some fireworks coming.

Written several pages ago - 2 bottles, one with wide neck and one with narrow. Same amount of water.

Watts = Amps*Volts.

215 AH * 6V = 1.3 KWH
110 AH * 12V = 1.3 KWH

Basics of electricity, not engineering level.

[MrWizard]

One 6v versus one 12v
6v at 212 amphrs = 1272 watt hrs

12v at 105 Amphrs = 1260 watt hrs

But you can't use Only one 6v, you must have two in series, because you need 12v

What you get with 6v is heavy thicker plates and stronger construction

[jplante4]

furyous68 wrote:
That makes sense. I didn't think it was a voltage thing, but didn't realize that the 6v batteries were built stronger. Thanks!

I also notice that 6v batteries typically have significantly more AH than 12v.

Yes, and it's difficult to find a quality true deep cycle 12 v jar. Most of what you see in RVs is the "marine/rv" deep cycle which is rated in cold cranking amps rather than amp hours. These 12v batteries run around 105 aH each so 2 would get you 210. 2-6 volt GC2s run 225 aH.

[furyous68]

That makes sense. I didn't think it was a voltage thing, but didn't realize that the 6v batteries were built stronger. Thanks!

I also notice that 6v batteries typically have significantly more AH than 12v.

[MrWizard]

its NOT voltage, its battery construction
6v are stronger construction, that will withstand the abuse of RV use
better than the avg 12v wet cell

there are some really good 12v AGM batteries out there, but they cost more than the 6v GC batteries

[pianotuna]

There are attributes to both 6 and 12 volt.

6 volt wins on thicker plates and on cell count.

12 volt wins on ability to power a LARGE inverter, and on resistance.

Six volt Golf cart jars are cheaper per amp-hour than deep cycle 12 volt units.

The ultimate battery bank would be six two volt cells with an amp-hour capacity of 800.

Any reasonable voltage battery can be made to work well in an RV.

[furyous68]

So, we have an electrical engineer down the hall from our office & he was wondering why multiple 6v setups instead of multiple 12v setups. He couldn't think of any real advantages to the 6v batteries over 12v (other than maybe congiguring for a certain space requirement. In fact... the wiring would be simpler to run 12v batteries in parallel. If AH are equal, is there any advantage to one system over the other?

[Almot]

Yes, Mr Wiz, this is exactly what I used to do with that little pot in the photo. With sugar mixed in before filling it with water, to give it time to dissolve. Only don't add cold water after, prefer with a few grounds but hotter. Those few that get into the cup, settle to the bottom. Arabs say that coffee should be hot as a woman's kiss and sweet as a honey.

[MrWizard]

Almot

that is the fancy way for camp fire coffee,
put cold water and coffee in a pan, heat, when it foams up, poor a little cold water on top to settle the grounds, carefully poor the coffee out

[Almot]

I use an instant variety of hot chocolate, no gadgets required. Keeping it simple. Few teaspoons of powder with whatever beverage you prefer. It's just one of ingredients.

Of course, a few teaspoons of hot chocolate in a glass of schnapps would be, er... not the same as a cup of hot chocolate with a little schnapps. Need to try this some day 🙂

[furyous68]

Lol... that's funny. I wasn't even thinking about it since I don't drink it. I use the MyJo for hot chocolate & apple cider. Before you make fun... I put peppermint schnapps in the hot chocolate & bourbon in the apple cider :W

[2oldman]

Since boondocking posts so often turn into 50 ways to make coffee:

Make coffee 2014
Coffee 2016
Coffee boondocking 2015-2017

[Almot]

It's like Melitta only with k-pods option. IMO, if you really love coffee - don't use pods.

[furyous68]

I've got one of these for backpacking: https://www.myjocoffee.com/

Works great with the k-cups or the refillable k-cup adapter it comes with. Should probably just buy one for the RV