BajaNomad

12 v vs 110.....again

volcano - 5-29-2012 at 05:39 PM

Been reading some past conversations here on this subject. I had made up my mind, only to recently be swayed the other way again. Tired of this waffling. Please..slam me with your opinions and help me settle this once and for all.

Cabin is way off grid, approx 700 sq ft.in size. Is rough wired for 110...wiring is pulled, but no fixtures, switches, breakers, power source. Outlets for 6 plugs, and 4 lights.

My power needs are for maximum of 2 lights on at one time, a mini rv fridge (3 way ac/dc/lp ), and eventually a tv/satellite receiver, and possibly eventually a small water pump.

I would like to start formatting a small solar/battery system.. I am only at the cabin at this point for 3 to 4 weeks in the winter. I plan to get portable solar panels and pack them in when not in town. Seems like the batteries will need to go dormant as well...as bad as that is.

opinions....12v, 110.....again...please

if wire runs are longer than 22 ft...then the existing wires are no good for 12 volt?

Udo - 5-29-2012 at 05:50 PM

If you decide to go the 12V way, buy AGM (google it) batteries. Yes, they are expensive, but you get 4 times the battery life and none of the maintenance.

willardguy - 5-29-2012 at 07:04 PM

well if you want to run a sat receiver, game over, you need an inverter.

Fernweh - 5-29-2012 at 07:08 PM

Quote:
Originally posted by volcano
Been reading some past conversations here on this subject. I had made up my mind, only to recently be swayed the other way again. Tired of this waffling. Please..slam me with your opinions and help me settle this once and for all.

Cabin is way off grid, approx 700 sq ft.in size. Is rough wired for 110...wiring is pulled, but no fixtures, switches, breakers, power source. Outlets for 6 plugs, and 4 lights.

My power needs are for maximum of 2 lights on at one time, a mini rv fridge (3 way ac/dc/lp ), and eventually a tv/satellite receiver, and possibly eventually a small water pump.

I would like to start formatting a small solar/battery system.. I am only at the cabin at this point for 3 to 4 weeks in the winter. I plan to get portable solar panels and pack them in when not in town. Seems like the batteries will need to go dormant as well...as bad as that is.

opinions....12v, 110.....again...please

if wire runs are longer than 22 ft...then the existing wires are no good for 12 volt?


Volcano,

get some AGM batteries as mentioned by Udo. A small dinky solar panel will keep those batteries maintained when you are not there - and NO load is connected!

Forget those RV fridges - go look at an Engel 12V/120V fridge. They are very well insulated and using very little electrical power, even in the 12V mode. If I turn it up to high - everything inside freezes.

Try to find you lighting fixture with LED's or make them up yourself.

The needed wire size depends on the load attached and the overall length. If you started off with a #12AWG size wire, you are in good shape. Install multiple separate circuits (12V) so the wire length is kept short.
I have seen small solar chargers/controllers with 4 fused circuits being used at my friend's far away rancho - in the BCS.
I got a 750W inverter for the 120V appliances, worked well with a little 4" grinder and probably with other small appliances as well.

Karl

volcano - 5-29-2012 at 09:16 PM

unfortunately i am not there and do not know the wire size..other than it is appropriate for 110.
It appeared that the wiring is already set up for about 3 circuits...and two of the runs have to be 25 to 30 feet
will look at the agm batteries and the Engel fridge..thanks

ncampion - 5-29-2012 at 09:51 PM

Another vote for 110 VAC with AMG batteries. Leave a your panel/charge controllers set up and connected while you're gone to manitain the batteries. (unless you're worried about theift) You can still kill AMG's by letting them discharge while you are away. Modern inverters are very efficient and then you don't have to fool around with any kind of dual system.

volcano - 5-30-2012 at 06:13 AM

I'm along a road and off away from other homes, so i cannot leave the panels set out, but could hook up a small panel to keep the batteries loaded

Bajalover - 5-30-2012 at 06:36 AM

Would like to chime in on this one.
Before going out and buying a bunch of stuff and wasting cash, would
strongly suggest reading up on solar and battery systems at
http://www.windsun.com/index.htm

Bajalover - 5-30-2012 at 06:43 AM

Sorry pushed the wrong key.
It's best you:
1- add up all of the loads you'll have (max case whether now or later)
2- since batteries shouldn't be discharged more than 50% to extend max life, power availability needs to be matched with amp hours used in one day.
3- calculate the number of days you may not get a full charge - I know, I know - in Baja it's always sunny......:bounce:
4- match the solar array to the battery bank size.
These are just a few ideas. You'll find alot of good information at the web site I included in the last post when I pushed the wrong button on the laptop.
Good luck - FYI - my winter and part of summer place in the SoCal's Desert is off the grid and runs approx 234 amp hours daily. It includes a swamp cooler, 42" led tv, internet, power tools, etc etc.
Hope to hear see what you develop at your cabin.

Russ - 5-30-2012 at 09:14 AM

IMHO I think you'll be ok with what ever wiring has been installed for a simple 12v system. But get the good battery and LED lights. AC wiring isn't ideal but it'll work.
Some of the cheap inverters with square sign waves play hell on electronics. I have a $14 Amazon charger that I tested on 2- L-16 battereies and a 45 watt kit and it charge up ok.
Here it is:
http://www.harborfreight.com/45-watt-solar-panel-kit-90599.h...

45W kit.jpg - 36kB

Bajajorge - 5-30-2012 at 11:40 AM

Sounds roughly what I run in my RV/house. Fridge on propane, unless you buy one of the new 12v/110 fridges. Propane water heater, Shurflow 12v water pump with 6 gallon water pressure tank, running on separate battery, 80ah, and small 15w solar panel. Inverter, 2500w pure sine, will run newer LCD TV, laptop computer, sat receiver, couple of 75w(9w) ecolights and LED lights easily, with only 500 watts worth of solar panels.
I have watched 10 hours worth of TV and had lights on for some 5-6 hours with no problem. Batteries 600ah, go from full charge to 12.4v at bedtime(usually 2330).
Solar panels face 169 degrees S, at approx 30-35 degrees angle(depending on time of year).
Never, ever let your batteries go under 11.9v.:no: Leave at least one solar panel up to keep your batteries charged and leave an ecolight on to make your batteries discharge and charge in your absense.
I run a 4000w motor home generator for times when the sun goes bye bye, and for when Mama just can't live without air conditioning. I turn the generator on for my morning English Muffins, and for nuke popcorn. My coffee pot is a Coleman propane, lookalike Mr Coffee. Life is good in the Baja,:biggrin: nearest store bought electric pole is about a mile from my place.

bkbend - 5-30-2012 at 06:11 PM

For 4 weeks a year the Engle refer is a large investment. The RV 3-way may burn 20-30 lbs. propane in that month but you can run it for a lot of years before rationalizing the cost of a real refer. Those RV jobs are generally inefficient on electricity so that's probably not an option but you could experiment switching over during the day once your batteries are on float and see what the load is. My two cents on your real question is you're better off in the long run to go 120V and you've already got the wiring and outlets for it. Get an inverter and you are set.

volcano - 5-31-2012 at 07:16 AM

keep the opinions on all coming...all very helpful.

yes, the price of the Engel fridge didn't jive with my budget, and I'd like the option of gas/electric.........

thus far, I am leaning toward doing a partial system....for lights only...as maintaining a whole battery bank for just a month a year usage seems rediculous. the jury is still out on 12 v or 110....but it seems most advice......user and professional..lean toward the 110...the professional advice say the wires will heat up and be dangerous on long runs. If I do a temporary system....12 v would be fine..and purchased components would go to the final system.

how long would a healthy battery keep a charge..in warm weather? without the charging? Could having it periodically charged, instead of leaving a small charging system inplace, all year in my absence, be a possibility?

right now i pay $20 a month to have my place walked around twice a month....adding on other duties will triple my monthly caretaker pay out.