My first solar project. For expo trailer

[Gaswede]

Im putting together my shopping list now for this project while building my trailer. This will be a system that might get used 6 times a year for 3-7 days at a time. Take a look and shoot me all the critiques you can as I welcome all advice and necessary changes needed!!

I live in Ky and mostly camp in primitive semi-wooded areas throughout the SE US. The solar panel will be mounted on top of the trailer while traveling but removable once on location.

1- Im considering adding a mini fridge to the system too. The fridge I have available to me is a standard dorm fridge that would have to run off the inverter (i would assume) 24/7. Do you see a problem with that idea?

2- How would I convert my wiring from the inverter's output (standard household plug) to the 110v outlet? This 110v outlet will be waterproofed and mounted on the exterior on the trailer for convenience.

 

[teotwaki]

Best to try to calculate how many amp-hours you need to pull out of the battery on a typical day and night. Then you can design the battery and solar charging to provide a reliable supply.

I think that the dorm fridge is way less than ideal. Very inefficient to convert DC to AC. Just watch for a deal on a good used fridge or a scratch N Dent deal http://www.openboxdirect.com/Koldfr...-Fridge-Freezer-Black/KF430SD,default,pd.html

http://www.expeditionportal.com/forum/threads/23350-Cheap-Fridge-lt-400-shipped

 

[ajmaudio]

I concur that a dorm fridge isnt ideal. Converting voltage is just adding losses to the system. As far as running a fridge with just a 50 watt panel I dont see that happening at all. This is why most campers use propane for fridge. Its very easy to run lights, water pump, etc on small solar but hings like fridges not so much.

 

[Gaswede]

Thanks guys. These are the exact things that I needed to hear. I think it goes without saying that the refrigerator idea needs to be scrapped. It looks like my research and homework needs to continue. If anyone has any further advice or experience with what I'm attempting please let me know.
I'll gather my amp hour numbers and report back. My shower and stove will run on propane. Maybe I need to look into a refrigerator option there as well.
Thanks for the help on the wiring as well.

 

[teotwaki]

Forgot to say add fuses and/or circuit breakers to your plans. For when your trailer is parked plan on some sort of battery tender to keep your battery topped off unless you have reliable sunlight to deploy your solar panel. Solar Boulevard's web site has tons of great solar gear at good prices. Sierra Expeditions has awesome mil-grade battery clamps and other electrical must haves made by Blue Sea and others. Adventure Trailers (AT Overland) also sells parts.

For battery cables buy inexpensive jump cables at Harbor Freight for wire (cut to needed length) and they used to have inexpensive crimpers for large lugs.

 

[Semi-Hex]

Thanks guys. These are the exact things that I needed to hear. I think it goes without saying that the refrigerator idea needs to be scrapped. It looks like my research and homework needs to continue. If anyone has any further advice or experience with what I'm attempting please let me know.
I'll gather my amp hour numbers and report back. My shower and stove will run on propane. Maybe I need to look into a refrigerator option there as well.
Thanks for the help on the wiring as well.

I think that calculation power consumption is very important when building these. I haven't been bitten by the refer bug but i have gotten spoiled by some things. I charge our iPads, have a water pump, more lights and other things than when I started. Like teotwaki mentioned, fuse the heck out of everything. I have only 45 watts of panels and do really well. Remember, even bad sun is better than no sun, so keep the panels out as much as you can.

 

[ajmaudio]

Thanks guys. These are the exact things that I needed to hear. I think it goes without saying that the refrigerator idea needs to be scrapped. It looks like my research and homework needs to continue. If anyone has any further advice or experience with what I'm attempting please let me know.
I'll gather my amp hour numbers and report back. My shower and stove will run on propane. Maybe I need to look into a refrigerator option there as well.
Thanks for the help on the wiring as well.

Just to be clear, you can run a fridge on solar.. but you will need at least a couple hundred watts more than likely. I will say though.. one nice thing about propane is that a typical small camper fridge will go a month on a typical bbq tank (20 pound). That said propane is a recurring cost, but its fairly cheap. If your using it to cook already by chance it starts making more and more sense. I do love solar, and if I was willing to put more batteries on my rig I would go that route. But not at this point. One final note on solar and fridge... make sure you have enough battery reserves, or a way to use your vehicle as a backup source in case you run into prolonged bad weather(low solar production)

 

[Gaswede]

awesome points guys and I appreciate all of it. I haven't looked into the propane fridge yet but I did look up the DC fridge option and it turns out they're pretty pricey. depending on propane fridge options, I may be sticking with ice for a while!
as far as consumption usage, I'll probably by utilizing power items only at night intermittently.
for my consumption numbers I came up with this so far...

interior led's (2- 8' strips) - 3.25 amps

h2o pump - 4.4 amps

car radio - 2 amps

iphone - 1.5 amps

ipad - 2 amps

battery monitor - 30 ma

12v fridge - 1 amp

(4) ext lights - 2 amps total

TOTAL = aprox 17 amps.

 

[unseenone]

12v DC fridge -- 2.5 - 5 amps x 12 hours a day (24 hours) run time.

 

[Ozarker]

There are some new dorm fridges and A/C window units that are much more efficient than just a couple years ago. Some mini fridges are for electric only for marine and RV, one is sold by Home Depot. The fridge I looked at had a 15 amp start up and ran on 10 amps. Best not to use car batteries for solar, even AGM, look into Triton 105 R, built for solar and about $115.00. 2 deep cell 6 volts has higher amperage and are wired for 12v, best bang for the buck until you get into battery banks as used for off grid homes. 200 watts should do for A/C and a fridge, dual battery and have a small generator to charge to top off the batteries as needed. If the budget is tight, you can look for used golf cart batteries and get reconditioning kits, acid and bring them back to life. I like redundancy, small gen set, solar, a`matched battery bank, 3000 watt inverter, as well as`separate 12v for less demanding appliances. Match and balance you lines to the load.

I'd agree, a mini fridge isn't made to bounce 3 feet in the air on a 8' trailer or ride at a 20 degree angle for 30 minutes, some proper prior planning might be in order, some engineering with a simple gambled base might help. A mini fridge can be 4.5 or 5 cubic feet, not 20 or 40 quarts.....then you may not need that much room. OTH, you may not need to keep the fridge plugged in all the time either. Most anything you buy, regardless of price, can be made better. If a cheap mini runs a third of the time as the slide jobs, you're probable ahead, IMO, at the same price or getting by cheaper, but you have had 3 times the storage as well as a freezer for ice. Also have an ice chest, LOL.

 

[003suns]

I like your ideas.

I will follow this thread, thanks.