connecting solar system to camper - Small Cabin Forum (1)

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Small Cabin Forum / Off-Grid Living / connecting solar system to camper

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optimistic Member	# Posted: 2 Oct 2012 16:25 - Edited by: optimistic Reply Hey everyone! been some time since I last visited this great forum! Just to recap - I bought a 16 acre piece of land in upstate ny with a friend of mine. We will be sharing it. I am having a road (1200ft) put in in the next few weeks and then I plan on plunking a camper (fifth wheel to be accurate) over there and converting it into 'cabin living' to serve me for the next couple of years until I build a real cabin. The thing that I want to cover as soon as I get there is the power. I was told by a camper yard salesperson that if I buy a solar kit with an inverter then I would be able to simply plug it into the plug that charges the camper itself... He said that although it is stupid in terms of the electricity being converted from 220 twice - it is the easiest thing for me to do... Now, I have no clue about how this thing works. I know nothing about electricity... Will his idea work - can I simply plug my solar kit to the plug (where you charge your camper) and I am home free? Thanks!!!!

Rob_O	# Posted: 2 Oct 2012 17:10 Reply Quoting: optimistic Will his idea work Yes Quoting: optimistic can I simply plug my solar kit to the plug (where you charge your camper) and I am home free? Not really, if you do it his way you are basically doubling the losses involved in getting the power from the panels to the plug A better way is using a charge controller between the panels and batteries. It's not hard to do, and has been covered in detail many times on this forum Quoting: optimistic I know nothing about electricity Time to start learning. First thing you need to determine is how much power (watt-hours) you need, from there we can help you determine what size system you will require.

optimistic Member	# Posted: 2 Oct 2012 17:21 Reply Rob - When you say batteries you mean the camper batteries or the solar kit batteries?

optimistic Member	# Posted: 2 Oct 2012 17:49 Reply From my limited knowledge, when you plug an RV to a power source (which is regular household power) then it charges 12V batteries in the RV. Once you want to turn on a ligth, for example, then it pulls the power from the 12V battery, but it converts it first... Now please let rephrase the question: I intend on eventually using whatever I buy for the solar system (let it be panels, converter, charge controller that was suggested, or any other thing) in my cabin so I want to plan ahead without buying something that I won't use in the cabin. If you had a fifth wheel off the grid and are coming over there every second or third weekend - how will you construct the solar system for it with the thought of using the system late in my cabin?

MtnDon Member	# Posted: 2 Oct 2012 18:53 Reply As Rob pointed out, the RV salesman is wrong. Doing as he says may be simple but a terrible waste, especially in view of your eventual goal. More later; right now we're heading out for a 35th Anniversary dinner.

optimistic Member	# Posted: 2 Oct 2012 19:07 Reply Congrats!!!! wow... 35 years is more than I have lived. Nice!! Can't wait to hear your thoughts!

Just Member	# Posted: 2 Oct 2012 21:44 Reply I am no expert but when i hooked my 1000 watt inverter to my trailer 110 plug it fried the brand new inverter in 10 seconds before i could pull the plug . later i returned the inverter and they gave me a new one because it had a 30 day garantee. not wanting to cook the new one i asked a electriction what could have caused the fire . he said the charging unit in the trailer had a capasitor in it that back fed into the inverter and did the damage . so i took the charging unit out of the trailer and pluged the 110 panal into the 1000 watt iverter and the 12 v panal fused to my solor battery bank and have been very pleased with it's performance . it's been up and running for 5 years.. we have a very small system including a 15 watt panel a charge control and 2 140 amp hour deep cell batteries + the 1000 watt inverter we use it sparingly 2 days a week on average we run 4 cfl 110 bulbs one at a time , and use a 900 watt microwave and a small shop vac once in a while . we also have 12 volt led . lights to replace the trailers old 12 volt lighting, and a 12 volt car radio. not sure why it happend but it did ,be carful ,hope you enjoy the place i know we do.

MtnDon Member	# Posted: 2 Oct 2012 22:25 Reply RV: Newer RV's use more electrical power than older ones. Sorry I can not give you a cut off date, but the refrigerators in newer ones have more electronics using keypad controls and digital displays. The refrigerator in my old RV used 0.0 amps when operating. Newer ones can use 1.6 amps for every hour they are operating because of the newer controls. Not a big deal when parked in an RV park or plugged in at home. But when doing an off grid thing it must be considered when selecting the power options. Plug in solar kits: Most I've seen are not the best packages for the dollars spent. Most I've looked at are deficient in their battery capacity. That's my opinion. It makes no sense to use a battery external to the RV to supply DC power to an inverter that in turn supplies 120 VAC to the battery charger in the RV that in turn makes DC power to charge another battery or batteries inside the RV. Those batteries in turn supply DC power to another inverter to run the microwave or supply DC power to RV lights\, the RV furnace, etc. Overall that could waste 20% of the power stored in the first set (external) batteries. The hard question to answer: That is "how much power capacity will you need in the cabin that will be built later? Will it be similar to the power used in the RV or will it be more? Twice? ??? What will heat the RV? What will heat the future cabin? In my experience RV heaters are power hogs. They are usually forced air furnaces and can easily use more than 5 amps at 12 volts when operating. Ours used 8 amps at 12 VDC (=96 watts). So if the cabin uses wood there is a savings of power that can be used for more lights or whatever in the cabin. So, choosing wisely for PV panels, charge controller and the batteries etc. depends upon an accurate assessment of the power needs now and future. IMO, it is best to come up with the "right" numbers now and buy the equipment once, rather than buy a second set later. The way technology changes it can even be difficult to match additional equipment to existing equipment a year or two after the initial installation. Batteries: Batteries that come with most RV's are barely up to the job. They seldom have batteries that are at least equal to golf cart batteries. GC batteries are, IMO, the minimum quality that should be used in an off grid system. The only good thing, IMO, about batteries that come with most RV's is that they are cheap and let one make mistakes less costly during the learning period. With care and no abuse they can be made to last three years tops, IMO. That could be okay as when the cabin is done if more storage capacity is needed then you would buy all new golf cart batteries. It is bad practice to add to existing batteries after a year. So, have you an eye on any particular RV? Check the make and model of the built in appliances; range, refrigerator, furnace.... Check the mfg websites for info regarding power requirements and use. Add in estimates of other uses; lights, microwave, TV, audio, whatever. Try as best as you can to come up with an accurate worst case of the daily power needs. Then the PV system can be sized accordingly. Anything else is somebody's guess. Some guesses are better than others. FWIW, the RV setup I was happiest with used 4 golf cart batteries with 200 watts of panels. That was for our use, our sun, and so on. IF you have a small generator and a good battery charger that could be used as the major power replenishment source as a temporary measure. We used an inverter generator for a number of years as our main power source until I got into PV. The downside is the bother, noise, smell, gaoline, oil changes, etc. The upside is a generator can be handy at almost any time and then when you buy PV panels you can maybe come up with the best setup after that initial learning period. I really don't like generators as a primary power source but they do have their place. With a generator as primary re-charge power you can use a small (15 watt or so) PV panel and a cheap controller to maintain the batteries between uses. Notice I said maintain not re-charge. I found that 20 watts was sufficient to maintain the batteries over a 4 month winter absence. Come spring the 4 GC batteries were full and ready to serve.

optimistic Member	# Posted: 2 Oct 2012 23:06 Reply Great stuff Don. A lot of info and I do have some answers already - The RV I have my eye on is a huge 40ft fifth wheel from 1994. Not sure how old is that considered. The guy mentioned that everything works and that the fridge is on propane and electric. I will get the model number from him so I can try to find a user manual online and more info tomorrow. I completely see eye to eye with you on the "buy once" perception. Which is why I think I should buy the system 'as if' it is for the cabin. Cabin plan - 500sqft cabin. Electric usage: I only intend on using the cabin for a weekend every couple of weeks or so, and I will have as many windows as possible to avoid using any lights during the day, I think that my usage will be very minimal... So for the sake of easy math I am estimating that from when it gets dark -5pm until we go to bad at 12, we will have about four 14W cfl bulbs on all the time (mostly 2 but sometimes 6 or 8 so I averaged it to 4 constant). We do want to have a small tv and streamer (a device that connects to a hard drive and 'streams movies" on the tv) , fridge, one small fan for the summer, and the ability to charge a laptop or cell phone if needed. We will also have an RV pump (for the cabin that is), and maybe a propane water heater which I am assuming uses a bit of power. We will heat with wood and cook on propane - in both the cabin and RV btw..... That is about it for electric usage. Will this suffice for understanding my solar needs? I plan on buying a generator for when I run heavier tools and to 'top off' the batteries if needed to. Knowing this, you think you can advise me on what I should purchase? I will connect the solar system to the RV as you tell me to. I have no preferences.

optimistic Member	# Posted: 2 Oct 2012 23:10 Reply oh and Just - thanks for tip! I will try my best to avoid this mistake but I am sure I will make my own.

MtnDon Member	# Posted: 3 Oct 2012 00:05 Reply Quoting: optimistic the fridge is on propane and electric. Just to be sure you know... the electric is really only for when grid connected. Not for use off batteries, although some do have 12 VDC settings, but that only works well when the engine is running. What sets the propane system apart on newer RV's is the need for 12 VDC electric whenever it is On. 1994 is probably old enough to have a refrigerator that requires no power at all, unless it is to just run the light in the box. One other RV caveat... the battery charger built into many older RV's and even many newer ones, suck. They are a poor compromise; not enough DC output to charge a battery quickly and too much for a float charge without causing dehydration problems with the batteries. That's some are less than ideal, not all. LOADS: make a list of the actual power use and the hours. Be honest in estimating. Think worst case. Also think about how many cloudy days you want to cover; days without much good sun. Use the off grid calculator in the resources area if you want. Or this one RV water pumps can use 7 amps or so, but don't run long unless you shower a lot or long. You're young, 14 watt CFL's will likely work for you. Older geezers like me like / need 23 watt CFL's. (60 yr old eyes need 4x as much light as 20 yr old eyes, double at age 50 compared to age 30. You're already on the downhill side.

optimistic Member	# Posted: 3 Oct 2012 07:43 Reply I am definitely on the downhill side... I will work on a better estimate for loads later today in school. Thinking on the RV issues you mentioned - what will be my best course of action? If you wanted to use an RV as a cabin for a couple of years like this what will you do for power?

razmichael Member	# Posted: 3 Oct 2012 08:03 Reply Hi Optimistic, Along will all the great advice already given, I'll add my experience (mileage will vary based on use, needs, sunlight etc etc). I took much the same approach as you when we started with a pop-up trailer about 3 years ago and last month starting putting in the cabin. I'm going to assume that your RV, being older, is configured much like our pop-up, only bigger! Most RV's and such as designed to run mostly from shore power and any battery is only to provide limited coverage. I'll cover what I did - the popup has a converter that does a few things things, input 120VAC, distribute the 120 through the circuit breakers to the outlets, convert 120 to 12DC, distribute the 12V to the lights, pump, furnace fan, propane detector etc. It may or may not charge the battery but, given the age of both of our trailers, any charger would be very basic. So, for stage one I added a few components and did a basic mod to the converter. This included two 6v deep cycle batteries, an 1800w inverter (with battery charger, auto switching, control panel), a bunch of switches and wiring stuff. I wanted to continue to use the trailer AC and DC distribution system (why not) so I bypassed the converter 120-12V component but fed the 12V back into the fuse system. Note that I did this with a toggle switch so I could run either way. I added 30 amp male and female plugs to the various 120 wiring between the converter and inverter so I could easily remove everything later. After changing lights to LEDs I could now run the pop-up for days and days without much drain on the batteries. Occasionally I would turn on the inverter so my wife could use her hair drying or to charge power tool batteries. I charged the batteries either with my small generator or would take them home (very heavy). This year I added in two solar panels (330 watts total) and a charge controller to the set-up. All this to say - last weekend I removed the components from the trailer and put them into the cabin (panels not mounted yet). With one connection in the trailer converter it is returned to the original functional state. In the cabin I'm using LED bulbs (these are standard base bulbs so fit in all standard sockets - the quality has gone way up recently and the cost down) and have gone overboard on the wiring size to reduce voltage drop but my assessment of needs indicate I should have all the power I need. This is especially true as my use pattern will be similar to you - mostly weekend use so any battery drain that cannot be replaced completely by the panels will be sorted out while away. Obviously the wiring and fuse systems in the cabin are different from the trailer set-up but I tried very hard to make sure what I purchased for the trailer would be usable in the cabin. if cabin needs increase I can add more panels (the charge controller is large enough) or double up on the batteries. Originally I did up a number of diagrams and photos at URL The panels and charge controller were added much later so not shown here.

MtnDon Member	# Posted: 3 Oct 2012 10:37 Reply Quoting: optimistic Thinking on the RV issues you mentioned - what will be my best course of action? If you wanted to use an RV as a cabin for a couple of years like this what will you do for power? Most likely the age will mean it has the simple non electronic refrigerator. If it was newer and had an ECM then I would need more battery capacity and a solar panel to keep the batteries charged. Assuming it has an old style fridge it would be much like our old RV (more or less)... Two to four golf cart batteries for power; connected for 12 volts. I started out with a 2800 watt inverter generator to charge our batteries. I also used that to power the microwave. TV, etc ran off a small Cobra inverter. Lights were all DC, but I changed out many of the incandescent lights for thinlite fluorescent than ran on 12 VDC. I ran the generator every 2 to 3 days and charged the batteries through an Iota battery charger (good charger, better than the RV charger in my case). Size depends on battery capacity. Then had a 20 watt PV panel to float the batteries when the place was vacant. Used that setup for a couple years. Then bought 200 watts of PV and a charge controller. That could be skipped depending on how much the generator use bothered you/me. If using the RV in winter look into covering the inside of the windows with that clear film "storm window" plastic. RV's don't usually have great windows and that made a huge difference with ours. I also made foam plugs for the overhead roof vents. Get a small air compressor so you can blow out the water lines in freezing weather. Or use the RV anti freeze to protect things. RV's usually have drains built into the water lines to aid in freeze protection. At least mine did. If the RV does not already have an automatic changeover propane regulator consider getting one. Get extra propane tanks so there can be full ones on site while you refill the last ones that got used up. 40 pound is a convenient size for handling. If using the RV in cold weather check out how much propane the furnace draws when in use and see how the cold weather affects the delivery of propane from the size of tank you have. Sometimes 100 lb propane cylinders are required.

MtnDon Member	# Posted: 3 Oct 2012 10:39 Reply About lights. Today if I was replacing RV lighting I'd also consider LED's. There are lower prices today, but IMO and my eyes, many are still too dim to be of much use. YMMV

Rob_O	# Posted: 3 Oct 2012 21:36 Reply Quoting: optimistic If you had a fifth wheel off the grid and are coming over there every second or third weekend - how will you construct the solar system for it with the thought of using the system late in my cabin? Well, if it was mine I would... Eliminate the factory charger/inverter, replace with 600W sine wave inverter with low idle current and high efficiency Batteries: 4 golf cart batteries Solar panels: 200W@12V * 2 Charge controller: Xantrex C40 w/display Metering: eBay China specials Emergency charging: Good jumper cables All that, plus some wiring will set you back about $1500 and should give you more than adequate power for lighting and entertainment needs.

optimistic Member	# Posted: 3 Oct 2012 21:42 Reply Raz - your system looks very well thought off. I wish I could do that but I lack the knowledge. Unless it is possible to literally make a step-by-step plan that I can follow without knowing all the in and outs I doubt I can do it. Really impressive stuff! Don - Heating - I will install a wood burning stove in the RV so no need to worry about that. I will only use the propane for the fridge and cooking. Generator - I wish to only use it for emergencies, topping off if batteries are running low for some reason, or when I need to run some heavy tools. I was thinking about starting to buy things for the system now, have them shipped to my house, figure out how to connect them together (take pictures, post them here, and ask silly questions), so when I have the camper in place in hopefully 4 weeks - I can drive up and connect everything fairly quickly. So for my next question - what do I need? I hope that now that I have outlined my plan and aspirations you can make me a shopping list. Please ;) If you need more info then please let me know.

optimistic Member	# Posted: 3 Oct 2012 21:44 Reply Rob - Thanks for that! I will start shopping soon once I get all input in. Any rec's on where to buy panels? and the other stuff?

PA_Bound Member	# Posted: 3 Oct 2012 21:53 Reply I'm not so sure about installing a wood stove in an RV. What do others think of that? RV's are typically very efficient with their use of space, consequently getting adequate clearance from combustibles may be difficult. That, and I'm not sure how the stove pipe would install. You may be better off using the RV furnace, even if it does consume propane a bit faster.

MtnDon Member	# Posted: 3 Oct 2012 23:17 Reply Quoting: optimistic Any rec's on where to buy panels? and the other stuff? On a small order like one or two panels the shipping will sometimes cost more than the panels. I was lucky and had a good local supplier. I bought most things from them and picked up everything myself; only a 30 minute drive. So, I'd say start looking close to home and see what is available without needing to get into paying truck freight. Batteries in particular can be expensive to ship, but somethimes not too bad. Costco and Sam's Club can be a good source for golf cart batteries. Not all their clubs carry the GC batteries and they don't always have them listed on their websites. That's where I'd start looking for batteries. There are many here who could make lists of their favorite components. A few key questions... would you want to run a microwave, and if so do you want the convenience of running it off an inverter using the stored battery power? Or would you be willing to go outside, start the generator, use the microwave, go back outside and shut down the generator....? I've done it both ways and you can guess what I was happiest with. That choice will decide if the inverter needs to be larger or smaller as the microwave probably uses the most power. But a list of what devices you would want to power off the inverter, and the power draw of each, would enable intelligent recommendations. Keep in mind that with things like microwaves, the rated power, such as 600 watts. is not the actual power used. The advertised number is generally the cooking power. A 600 watt microwave may actually consume 900 watts (as an example) when operating. FWIW my favorite vendors have been Affordable Solar in ABQ, The Solar.Biz in Glenwood, NM (because one is local and the other close and both have been fair and knowledgable), and Northern AZ Wind & Sun, Flagstaff, AZ. Plus solarseller.com from Long Beach, CA for a lot of things like fuses, DC breakers, Thinlites and other. A wood burning stove wood be a problem to install in an RV, IMO. As mentioned the required clearances are quite often greater than the space available. There are some small stoves that can burn wood or charcoal that are designed for use in boats / yachts. They can be fitted into cramped spaces safely, but mostly they are very expensive for their size. The ones I've seen are tiny and would need more time and care in fueling. My RV experience has been that they leak heat to the outside in cold weather. Ours were fairly easy to keep warm with the propane furnace, but they can also use a good amount of propane and battery power. I always looked at the fuel and power use as something that was going to end, maybe last for a few years, and as such was bearable. Here's a link to one of the less expensive ones that look like it could work in an RV It can only put out 8000 BTU's which might not be enough with a long fifth wheeler. The furnaces in large RV's will usually use a blower and ducts to get the heat moved to where it is wanted.

razmichael Member	# Posted: 4 Oct 2012 08:45 Reply Quoting: optimistic Raz - your system looks very well thought off. I wish I could do that but I lack the knowledge. Unless it is possible to literally make a step-by-step plan that I can follow without knowing all the in and outs I doubt I can do it. Really impressive stuff! The diagrams are more complicated looking than they really are but this is a system that suits my needs and would not likely meet your needs (power requirements, space, budget etc - all the things that have been mentioned). I just pointed them out as they may give you some ideas. Make sure you review the information at 12 volt side of life Part 1 and part 2. This has some really good information although some of the technical stuff is a bit old. From your earlier descriptions you are not considering running microwaves etc but make sure you think things through really well before hand because it can be expensive or difficult to upgrade in some situations as your needs expand. For example, if you install a small inverter this requires specific length and gauge of cables from the battery. If later on you decide you need to increase the size of the inverter, this may also need a completely new set of cables from the battery - these cables get expensive as they get bigger.

optimistic Member	# Posted: 4 Oct 2012 08:56 Reply Don - My wife decided she wants a microwave and I rather not use the generator. Can you give me a break down of everything I need to buy, please? btw- I saw wood burning stoves installed in RV's before. I am not worried.

TomChum Member	# Posted: 4 Oct 2012 13:37 - Edited by: TomChum Reply Quoting: optimistic My wife decided she wants a microwave and I rather not use the generator. ..... OOOOOOF! Your wife just upped the size of the system you need. You will be spending $1500-$2000 on an inverter to run a microwave. I recommend to try cabin-ing without it for for a little while and see if all the running around in the background to save a few minutes via microwave is a worthwhile endeavor. If she's the one who has to start the generator I bet she quickly adjusts to setting a pot on the stove. Quoting: MtnDon IMO and my eyes, many are still too dim to be of much use. YMMV Don, you should order this 12v LED FLOOD light, if nothing else just to screw around with. Will cost you $20 but then you know what's available - it's bright. I'd like to hear your thoughts how this 6W LED compares to the 23w CFLs that you use. Not omnidirectional, but is a FLOOD. It has 1/4" spade terminals. I also like this 3W FLOOD (warm white color, of course) ($12.95). They use so little power (1/4amp) that you can just twist your wires onto the pins then cover it with a glue (like GOOP, or Hot Glue). Maybe silicone if it's the non-acetic acid type. Or you can even crimp a butt-splice connector to it. They last so long that you don't really have to worry about how/when the bulb needs to be changed, you can make a 'permanent' installation.

optimistic Member	# Posted: 4 Oct 2012 15:52 Reply Tom - I found this small cheap microwave on homedepot - http://www.homedepot.com/h_d1/N-5yc1v/R-202665780/h_d2/ProductDisplay?catalogId=10053 &langId=-1&keyword=microwave+600&storeId=10051#.UG3odJjA92s It uses 600watt. Will this allow me to get a smaller inverter?

Just Member	# Posted: 4 Oct 2012 16:28 Reply optimistic i have a 800 watt microwave with a 1000 watt inverter we have to turn everything eles off when we use it but it does work ...i had a 600 watt one but it was very slow ,,like 10 min. for one baked potato..

optimistic Member	# Posted: 4 Oct 2012 16:30 Reply Well that's the thing... I never cook in the microwave. Ever. for me a microwave is strictly for heating up cooked food. That is what it will be used for in the cabin as well. That makes it easier for me?

MtnDon Member	# Posted: 4 Oct 2012 16:52 Reply Quoting: optimistic I found this small cheap microwave on homedepot It uses 600watt. optimistic, sometimes you don't read what people post very carefully, or you do not understand what they are stating. here's a quote from a few posts back.... Quoting: MtnDon Keep in mind that with things like microwaves, the rated power, such as 600 watts. is not the actual power used. The advertised number is generally the cooking power. A 600 watt microwave may actually consume 900 watts (as an example) when operating. It uses more than the rated 600 watts of cooking power. Just how much more I have no solid idea, just a guess of maybe 900 to 1000 watts, but that is a Guess. The HD page states cooking power. The actual power used figure is usually hidden, sometimes not even mentioned anywhere in an ad. You may need to find and download the user manual or look at the actual nameplate on the appliance. And one more thing that plagues some cheap microwaves; some of them do not work at all on square wave inverter power. I have one that makes noise but does not raise the temperature of a glass of water by more than a couple of degrees in a full minute. It works fine on pure sine wave. Go figure.

Rob_O	# Posted: 4 Oct 2012 17:54 Reply Quoting: optimistic Can you give me a break down of everything I need to buy, please? Just send me your credit card number and I'll take care of it for you...

optimistic Member	# Posted: 4 Oct 2012 21:41 Reply Thanks Rob but that might be a problem Sorry about that. I should have read more carefully. Don.... Then with a microwave. Can you, please, give me a list of things to buy?

MtnDon Member	# Posted: 4 Oct 2012 22:26 Reply My list of items to use to build a PV system for an RV that could later be used in a small cabin. Note: this list is rather generic, no specific name brands or model numbers used. In places I have listed names and generally more than one. Those are brands I either have experience with or that friends have used successfully. No guarantees are made or implied as to whether or not the equipment will provide a system that will be 100% suitable for anybody's personal project. I have yet to see an estimate of the daily or weekly watt hours that will be used by the system operators. Without that I hesitate to make recommendations that are any more specific than the general things I have listed. If you go to a supplier of PV equipment and systems and he says, "here, this will work for you" without asking about the expected loads or use he is being dishonest or simply does not care and just wants to make a sale. The calculators that were previously referenced are not all that difficult to use. PV module(s) Mount(s) for PV module(s); ground, roof, pole? Grounding wire connector(s) for panels MC4 connecting cable(s) (match to panel, most should be MC4 today but there may be some MC3 still being sold) Combiner box [Outback, Midnight Solar] Power disconnect (if a breaker is used, must be DC rated) DC rated Lightning arrestor Eight foot ground rod and connector Ground wire Wires to connect from combiner to charge controller Disconnect / breaker before charge controller (DC rated) Not needed if PV modules are close to charge controller Charge controller [Morning Star, Xantrex, Blue Sky] Disconnect / breaker after charge controller (DC rated) Batteries [golf cart or better such as L16 (if wet cell type, owner should have a battery hydrometer) Battery filler (there are ones that will auto stop when adding water, makes the job easy and precise) Cables and / or buss bars to connect batteries together Type T fuse at battery output for dead short circuit protection. Must have capacity large enough to permit the inverter to operate into whatever its safe overload rating is. Breaker (DC rated) between Type T fuse and inverter for overcurrent protection Wires from batteries to inverter Fuse block (DC rated) or breakers (DC rated) for overcurrent protection of DC devices. Inverter [Xantrex, Magnum Energy, Outback] (best would be an inverter / charger combination unit. Separate charger is okay. Charger should be 3 stage type; 4 stage with equalization charge is best) Inverter note: There are sine wave and so called modified sine wave. Modified sine wave are actually square waves. Some things do not like square waves; motors run hotter and use more power. Some microwaves and computer controlled sewing machines don't work at all. Lights, TV's, radios usually have no problems though some devices make a more pronounced 60 cycle buzz. Inverter size note: The continuous power rating of the inverter must be at least as large as the largest load or the largest combined load that will be used at any one time. The big variable is likely the microwave. Our small one uses just under 1000 watts. Our big one uses 1700 watts. AC overcurrent protection (fuses or breakers; AC rated) for any AC circuits that do not have any other overcurrent protection. In an RV use the built in stuff if possible. In a cabin the the SquareD brand, model QO and QOC breakers are handy as they can be used on both 120 VAC and 12 to 24 VDC circuits. But not in the same enclosure. Note: in an RV there should already be both DC fuses or breakers and AC fuses or breakers for overcurrent ptotection. These may be combined with the built in converter / battery charger. The built in converter / battery charger should be disconnected or removed from the system when building a solar power systemusing equipment that can be later moved to a stand alone cabin system. Generator (for emergency or heavy duty tool use) Optional: system meter such as a Trimetric. Once programmed they act like a "fuel gauge" for the battery charge level. They are handy but not completely necessary especially if one learns how to use a hydrometer and a log book. General Note: If the system will be put through an inspection or permit process all items will likely have to be labeled with UL or ETL approvals (in USA). Some PV modules sold at steep discounts may not carry the approval labels. Same thing applies to some wires and cables that are commonly used by DIY. Auto battery cables and welding cables do not have UL or ETL approvals for example. Some inspectors will let welding cables pass, some won't. They do have that discretionary power. Absence of an approval label does not necessarily mean the product is inferior. It simply means the item was not submitted for inspection (and no fees paid). Wire sizes are not listed as this varies with loads and distances between connection points. The truly paranoid, like myself, will also install an AC rated lightning arrestor and ground rod on the AC side of the system.

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