Solar Power System

This instructable will show you everything you need to put together a pretty good sized electric solar panel system. Things you will need:

Supplies:

Solar panels
Charge controller
Battery charger
2 AWG cable
At least one 12 Volt marine deep cycle battery
Mechanical lugs
1 power inverter
1 Rubbermaid tote or other container
1 battery charger

Tools:

Cable cutters
Red electrical tape
Screwdriver
Drill
Crescent Wrench


Gather supplies and lets get started.

Step 1: Preparing the batteries.

The first thing you want to do is charge your batteries with a charger. This will insure they are charged to capacity and ready to go at set up. I purchased my batteries new and were only at about 60%.

While the batteries are charging, you can set up the solar panels and get them wired up and ready to go.

Comments

[Missions777]

Can you give a more detailed sequence for the parts. Solar panels go (what size is this wire?) to charge controller (what wire size here?) then to batteries then to inverter Is this right? I have six solar panels given to me. Is there a schematic for building the panel array the even shows the size of wire to use? Is there a detailed book I could buy? I am crippled with medical equipment that I can't sleep without. When our power is gone I have to sleep in the car. I'd like to be able to run a small light, my sleep apnea machine and a fan. Any advice appreciated!

[Dr.Bill]

My system cost me around $1800.
5-20 Watt panels
2000 Watt sine wave inverter
200Ah Trojan battery
10 Amp DC breaker
and ah whole lot of odds and ends.
Your I'ble inspired me to do it.

[Dr.Bill]

I forgot the 30 Amp SunForce charge controller.
The inverter is a Xantrex.

[kenpg67]

im setting up a smaller system myself but this answered a lot of the questions i had.

Thanks!

[jbaker22]

can you get more energy out of them by duct taping vaseline glass to the back?

[MacOSJoey]

Good setup! I think though that a better charge controller will help you a ton. I personally have a Xantrex C12 and C35, and they seem to work much better since they have equalization and PWM charging. Other than that, enjoy the "free" energy.

[ledshed]

Quick tip for multiple batteries in a parallel bank - take positive from one end and take negative from the other end of bank, this evens out the resistance of the joining cables making sure the batteries are drained more evenly.

[zsthorian]

Hey Mr. Chicken. Just tossing a couple things into your comments to help others that may be attempting your setup.

1. The solar panels need full sun with no shading what so ever, the efficancy of the PV panels is significantly reduced if they are even partly shaded.

2. Avoid any battery that has a CCA rating. The CCA stands for cold cranking amps and indicates a starting battery. Starting batteries should only be discharged to 80% capacity or they will be perminantly damaged. A Marine deep cycle battery with out a CCA rating will be able to be discharged to 50% capacity where as Golf Cart batteries can be brought down to 20% with out perminant damage. The down side to golf cart batteries is that they are 6 volt and would need to be wired in series and in parrallel.

3. One will want to vent the battery box to the outside. several people have spoke about hydrogen. Granted I have never heard of a battery box exploding, I have witnessed a battery explode in the battery room when it was charging. It is also a good idea to keep some baking soda close hand to nutralize any potential spills while topping off the batteries water.

[mongojr1]

Auto cables work great and less work

[cooltogo]

I share buildem4me's comment: batteries WILL emit hydrogen, a VERY flammable gas. The slightest spark, or even over-heating, can EXPLODE the batteries. The only exception to that is AGM sealed batteries - and they are WAY more expensive. Furthermore, your battery container must be protected from too much heat or too much cold. A frozen battery is a DEAD battery, an overheated battery is a dangerous battery. In order to prolong battery life, don't discharge them too much. Keep them at 80% 'full', and they'll last a LOT longer. This applies for this type of battery, unlike some 'electronics' batteries, where you "teach them a memory" by completely charging and then completely discharging them. An alternative to the marine battery is the golf cart battery. It is actually better suited to the demands of a constant gentle flux of charge/demand. A well-known brand name is Trojan. I've lived off the grid on solar power for ca. 5 years. Never mind the critique, however. You DID put together a very nice instructible, and having the guts to publish something like that is great.

[michaelusa1]

With excellent service at wal mart you can get your deep cycle marine battery replaced very well up to three years at any wal mart in the country. They are pro rated at 4 to 5 years so use em every day and dare them to go bad. just take em back to wally world and get a replacement for cheap.

[michaelusa1]

ATTENTION. For "the best" batt/solar set up and installation as well as what to stay away from can be found over at backwoodshome.com. A 6 part discussion and info on battery types, inverters, charge controllers, solar arrays for the small off grid system (or big if you expand it) This is a must see for a more complete understanding!! The author is a licensed electrician and already has been using solar/batt setup for years.

[aztecaa]

Just read your post after posting. What kind of setup are you running? I am looking to do a setup soon and not go broke doing it. I have a setup on the motorhome at this time but read that higher volt system is much more flexible in running appliances. If you have any pics for review please send me. Thanks

[Angus06]

So the batteries seem unsafe indoors and useless outdoors... What would you reccomend for this setup in terms of providing maximum safety as well as maximum usefulness? And by the way, thank you for pointing that out; that may well have saved me from blowing the house to smithereens.

[cooltogo]

I did not intent to say that the batteries are 'useless' outdoors. Their useful function depends on your ability to place them into an environment where they are neither too hot nor too cold.
An example of outdoor housing for batteries could combine a surrounding structure that is well insulated. It could incorporate passive solar heat by exposing a southern wall to radiant heat via a glass panel.
It could employ a venting system that makes use of the convective heat flow: a louvered opening near the bottom, and another louvered opening near the top of the structure, for instance - where the bottom opening would face the direction that absorbs the most heat: the south.
Such openings could be closed off in winter in order to contain the radiant heat that is absorbed through the southern window (but, SOME ventilation MUST be present in order to prevent the accumulation of hydrogen gases that emanate from the batteries).
My own solution was to buy AGM (aggregate glass mat) batteries that are maintenance-free and do NOT release any gases. I keep my battery bank INDOORS, and safely so because of the nature of the batteries. I got mine on sale 4 years ago, but usually, AGM's are much more expensive than regular wet-cell batteries.
If I had to replace my battery bank at this time, I would probably NOT buy AGMs again. I would buy a number of wet-cell batteries, (compare the brand Trojan), and I would build an add-on to my house, well isolated by a firewall, to house the new battery bank. I would also, at that time, put the add-on to additional use as a garage, fire-wood storage, workshop, etc. I would move my solar panels from their present location on the roof of my house to the roof of the add-on (which, of course, would have a south-facing roof slope).
If I were to seek a building permit for my plans, it would most probably result in a code requirement to have a distance between the 'battery building' and the house. If I chose to actually get and satisfy such an intrusion to my personal choice, I would most probably seek to use the 'distance' space as a walkway, or try to put it to some other good use.
The only reason why I WOULD deal with a permit would be because I would consider my property as something I will eventually sell off and move on, thereby having to satisfy inspection by the new owner's government watchdogs.
I am not planning to sell my place, so it is more likely that it will be left behind as leftovers of my life - kind of like the lifeless physical body that will also be a 'remains' - unless, of course, a being appears in my presence who loves the place as much as I do and wants to keep caring for it. I mean the place, NOT the body. The best that can happen to IT is some coyotes or crows finding an easy meal.
So, let's look at 'what is' and chuckle a little bit about it :)
And keep finding options. Rarely is there EVER a problem that has only TWO choices for solutions. We're just conditioned to not LOOK for the other choices :)

[lilykoart]

can we expect to see an instructables from you soon? :) thanks for the insight!

[Angus06]

Wow. Thank you!

[goatroper57]

hello iam fairly new at this ive been reading up on solar electric the last few weeks but i still dont know how big of a system i should use to run say my lights,tv, (3)tv satelite recivers /system and desktop computer and maybe a few other things the stove,refer,washer&dryer, hot water tank and a/c things like that would stay on the electric co. grid iam just lookin to save on my electric bill and we are complete electric in our 16x80 moble home so iam thinkin of makin my own solar panels that seems to be the cheapest way to go for them i just dont know what kind of solar cells & sizes to get and how big to build them and what size solar charger controller & inverter parts to get as i found a lot of stuff on ebay fairly cheap but like i said i have know idea of what to get so can you help but tell me in terms i can understand as iam not a electrial wiz then ill know what to look for on ebay hope yall can help oh and i live in south east missouri we do get our fair share of sun and snow here but not realy all that much snow maybe 6-8 inches a year if were lucky

[Zerocool818]

i have the same charger

[emmiesworld]

I'm Emmanuel by name, I really wanna kno how much energy can the solar panel store?I am working on my solar panel & inverter connectivity.I reside in Nigeria ,where there is a lot of sunlight.

[riverreaper]

how much did pannles like that cost an does keeping them clean vers dirty as A car make a differance? wish you had a vid it rains here all the time , wana trade water for power?

[Residential Solar 101]

Solar panels actually only need to be cleaned about once a year.  If you have any rain in your area, which it sure sounds like you do, that will go a long way towards keeping them clean.  When they're dirty their efficiency can drop a few %, but no so much that you'd need to clean them off with a hose more than once or twice a year. 

If you lease a solar energy system from a company that offers a solar lease they'll actually handle all of the maintenance and cleaning for you.  If you build 'em or buy 'em outright, you'll likely need to clean them once a year yourself. 

[riverreaper]

what about coffee makers ? they use or get used alot would sundrip be better than solor heated ?

[riverreaper]

what if i used a candle to heat half a pot of water an then took the sundrip container an sumersed it into the heatted water would the heat transfer enoght to get a hot cup of coffee or would i have to plug the heating pad in usen up everthing that battery had made the day befor , an not haven a cup of coffee to offer the garbage guy that still works

[riverreaper]

ok ok ill go give the led heads some qwestions

[ElectricMan1]

You should have used only 1 battery because it takes way too long to charge this setup.

[abadfart]

but it will last longer
 

[ElectricMan1]

well ya but dosen't it take a long time?
Have u ever completely drained them?

[abadfart]

ya i have drained it but if you have enough cells it doesn't matter  we use it in a caben and it runs a cb, a ham, a car stereo, chargers, and lights but we have enough cells that even with everything running 24/7 it always has power it only died when there was so much snow that it covered all the panels so there was no flow 

[useful1]

This instructible is awesome.  Thanks for sharing this with us.

Showing up how to wire it up in step 3 in parallel is very helpful.
I dont understand what all the complaints are in this one in the comments field.  Having a big 12V battery connected in parallel is more useful and easier to do than using odd voltages like 24V.

Im not worried about ventalation either on the hydrogen gas building up in the container.  I myself have kept batteries in a container and it is perfectly FINE.  Ill just head over to mine and light a match.  Oh hey, Im still alive.

Keep on writing up good stuff like this!

[Biker-74]

Connecting batteries in parallel is not the very best idea. The internal resistance of the batteries are slightly different. One of the batteries will deliver more current than the other one(s) and over time it's resistance will change, thereby adding to the unbalance. One battery will then wear out before the other battery/ies. Difficult to know which one is bad and needs replacing. At the least, make sure that a multi-battery setup consists of "twins" or "triples" by choosing the same brand, bought together, and if available check serial numbers to be as close as possible. You seem to have followed this, which is good, but it's not clear in the instructable that it should be done. The best is to connect batteries in series. This, of course, gives a different set of problems. You will either need a higher voltage source, or some kind of DC/DC step-up transformer. 48 Volts panels may be difficult to find and may be more expensive. A DC/DC step-up will have less efficiency and the loss may be discouraging. 48 Volts charge regulators may be more expensive too. Then you need either a DC/DC step-down or 48 Volts consumers. Not very practical. Having a single, very high capacity, 12 Volts battery is probably the best compromise for combined efficiency and life-time. It also makes it easier to know when the battery is ready to be replaced, since you know exactly which battery is getting bad. On the whole, a very nice instructable. Should inspire a lot of people to get into home power production.

[TFrosty]

Why not connect the batteries in series/paralell. That way you raise your total voltage and amps output.

[suptclark]

In the parallel connection,no current would pass from one battery to the next. Each would contribute to the 12 volt total as it was capable. Large trucks and buses use this type of connection all the time with no problem.

[hemant_saraf]

I have two clarifications... one, I have an inverter at home which charges the batteries from the grid electricity. It is a 24 v inverter at battery input with a 1400 watts power rating. What I wish to do is charge the batteries through solar power and not through the grid electricity. So if I connect a separate charge controller to the batteries for solar charging (as you've advised), then will it get mixed up with the charging circuit that is inbuilt in the readymade branded inverter that I have. Would you be able to advise as to what possibly could happen there ? second, what is the distance (length of the wire) between the solar panel and the charge controller you maintained and what is advisable? I am a newbie and based out of India. Would very much appreciate your inputs and knowledge that you share. Thanks in advance. PS : Being in India only means we operate on 230v, 50 Hz AC, Sun is good and very bright and so it makes sense to go solar here. Also I will be able to size the solar panel requirement based on the required voltage and also be able assemble them correctly for panels to be able to provide adequate charging current and input voltage for the battery bank that I have. Just fyi, I have two 12 v batteries in series to provide a 24v input to the inverter. Each battery is 160 AmpHours.

[riverreaper]

wallyworld sell car solor batt chargers cant recall exact price around 80.00 i think i belive by the pick it shows you can do it without pulling the battery outa your car even , it might be cheeper just to bank them rather than build a monster set up with all theses do`s an becarefulls ,dam they closed the junk yard down i could been rich .

[Mr. Chicken]

Personally, I wouldn't use both methods to charge the batteries. I would use solar or from the grid, but not together. I would connect to solar panels and disconnect from the grid. I don't think it would be a problem, but I'm not 100% sure. I'd be more concerned about charging from the grid unnecessarily. As for length of wire from the solar panels to the charge controller, make it as short as you you can to lower resistance and loss. Mine is at about 10 ft. Good luck.

[TheIronHobo]

does it matter the size of the solar panel? i have 1 12 v and 5 watt solar panel. can i build your exact rig with one two or three batterys and still have it work with my solarpanel?

[TFrosty]

How are you panels wired? Parallel, series parallel, or parallel/series?

[TFrosty]

Where did you get the charge controller?

[awang8]

It came with the solar panels which were from craigslist.

[gkimber2]

you might think about venting the tote to prevent buildup of hydrogen gas during charging.

[riverreaper]

could you vent the gas to a hydrogen car?

[Merakesh]

You also need to be carful of 2 toxic gases. Arsine and Stibine. If the batteries should happen to overcharge for a short while it probably won't be a problem. But if they get overcharged long enough they could produce a good amount. While the tote seems like a good idea, I recommend not using it for the gas problem. While I'm typing this I cannot think of something you could put them in though. sry :(

[Derin]

Make a box with two 120mm holes in the top,mount 120mm computer fans,one to draw and one to bring air into the case.Then wire those to the 12V array.

[riverreaper]

hows thous gasses on the inviroment ? is trying to save the planet really killing us all just in a difernt matter?

[luiseduardo]

I am new in solar power, question? this project can maintain a freezer of 5.o cubic feet, this freezer uses 242 KWH/year

[sasomanuel]

Hi. I have a similar set-up in my remote cabin; however, I store the batteries in a insulated box under the cabin (3 foot "crawl-space")and wire up through the fllor to the inverter and charge controller. I have a low-voltage lightbulb 9connected to the battery bank) in the box on all the time (in the winter)to keep some warmth on the batteries. I have found that it works well. Just a suggestion.

[riverreaper]

if you insulated the batts an used the lights in the cabin it would keep the moister out an nothing would mold on you

[DJnaSTYnuTS]

I hope those Batteries are ventilated. It would suck having crazy gases building up in there... By the way, I wouldn't keep them near or under the house, batteries explode time to time!

[aztecaa]

What is the best way to store Solar and Wind Power to... Also what do these big companies use to store the Solar Power to... Building a 3 bedroom home off the grid and looking at the best way to store solar power. Looked at many setups and don't want to go broke trying to do a setup. Thanks

[riverreaper]

3 bedroom? u coulda dug a deep hole an saved on heatting an cooling with half a story building an a duck head sign lol

[tuckoovam]

I'm new to this so I just have a question about wire sizes. What size wire did you use from the the charge controller? And from the batteries to the inverter what size was used?

[dusts]

I was wondering what you were able to run from this solar kit. I plan on building my own setup that can run a low power PC or maybe even a gaming pc if that's even possible.

[imajem]

How could power from the solar array be directed into the power grid? I know this is possible but don't know how.

[Fildain]

One problem with being connected to the grid is that you have to sell all of your power to the electric company at "wholesale" price and then buy what you use at retail. So unless you create twice the amount you need to use, the electric companies still screw you. =)

[cpotoso]

Not always true. In many communities (e.g. in mine) the electric co. will buy from you at the same rate as they sell to you. However, connecting to the grid is quite complicated and not really worth for a system this size (you'd have to go to several kW of power, costing many k$).

[imajem]

Thanks! I didn't know that BUT every little bit helps....just not as much as I thought, right?

[DesertSunShine]

I think I understand ? Check out this photo.. I'm using (4) 6 volt batteries and making (2) 12 volts batteries connected together to make a total of 12 volts for my Inverter. Is this correct ?

[Mr. Chicken]

It's hard to tell from that angle but looks like you've shorted the batteries. If I'm interpreting it correctly, it looks fishy to me.

[DesertSunShine]

Black lines are NEG.. Red lines are POS.. Maybe this graphic will help you.. Please let me know

[draftbounty]

May I ask? What's the different between DesertSunShine's setup and Mr.Chicken's setup?

[Mr. Chicken]

Yeah, that looks right.

[riverreaper]

why do solor pannle come in only pannles ive seen how they make them an thought a pole would much better at collecting all the sun rather than just the southerly direction as the solor part it self is a thin film they adhees to the pannle an with a pole you could put up 100`s vers a few in the same amount of space , has anyone looked into this if not why as pannles are limmited to amount of space , an if you used polesolor u could go strong enoght to get a windmill on top harnesing even more ppower ,or even on a water wheel type that was only sumerged a little catching waves  an sunlight at the same time , ok skip reading this im contacting bill gate i want a new computer for my ideas

[farhannna]

does anyone know how to calculate the right size for the cable : 1. solar panel to charge controller 2. charge controller to dc load 3. charge controller to batteries 4. baterries to batteries(if more than one battery) 5.battery to power inverter 6. power inverter to ac load please guide me on this one. i hope there are some calculation that i can refer on. im trying to do for 100w solar power system.im trying to do the solar panel for my room

[TFrosty]

Does anybody know where I can get a charge controller besides the one allelectronics.com has??????

[TWMCNANEY]

You can get one at notherntool.com great tools too! It's about 30ducks and it's the same one that is shown here!

[Electrolight]

First off GREAT INSTRUCTABLE!!! I was wondering how many killowatt hours do you think you cold run on your batteries till their dead(need to be recharged)? Also how long does it take to charge your 3 batteries with your settup? Lastly how many solar panels and batteries do you think It would take to run about 50 Killowatt hours a weekend? We have a small cabin in the mittle of nowhere, that we only visit weekends, and we want to make it solar powered. Thanks for the info.

[dayvo]

Check out this "plug and play" kit for weekend cabin use-
http://www.tscrenewableenergy.com/tsc_t3_s1_p2.php

[Mr. Chicken]

1) The batteries are rated at 125 Amp hours each. They way they are connected that's 375 Amp hours total. 375 Amphours/12Volts = 31.25 Watt hours = 0.03125 Kilowatt hours. So... about .031 kilowatt hours before recharging.

2) After having this set up for a while now I can safely say the panel is very much undersized for the set up. It is taking about a week to recharge sometimes. And now that winter is coming where I'm at it is taking over 2 weeks some times (if not longer). So, 60 Watt solar panels are not good enough for continual use of this set up. But, since my original plan was having this as emergency power, I'm still pleased with the results.

3) 50 kilowatts is pretty high. 50 kilowatt hours = 50000 watt hours. 50000/12=4166.37 Amp hours. 4166.37 Amp hours/125 Amp hours = 33.33 Batteries. So, about 34 batteries of this size to run the 50 kilowatts.

Here is a pretty good website about electric solar panel systems...

http://www.solar4power.com/

Hope that helps.

[cpotoso]

Check your units: 375 Ah * 12 V = 4.5 kWh.

[TFrosty]

so the solar panels are connected to the charge controller and the batteries are connected to the charge controller. Right?

[Pete3]

the math is kinda wrong there, 1 W equals to 1VA , that equals to 1V * 1A, so if the batteries are fully charged it gives you 375amphours*12Volts=4500VA hours and that equals to 4,5kW hours, so a 100W light bulb can shine about 45 hours on the batteries (its just hypothetical, coz you do have some discharge of the batteries over time, plus the inverter changes about 20% of the energy to heat) anyway, your instructions are very useful, next spring im gonna build a solar power system on my own, i was thinking to buy a broken solar cells from ebay, what do you guys think?, and sorry for my english i'm not american

[ahmedirshad]

I have a UPS (220V grit connected) with a battery qhat I wish to do is charge the battery through solar power.what possibly could happen in this case can i use my UPS with any change with the solar panel. I have no knowledge of electronics and solar electricity. but i like this to be done. Can you guide me in this regard?

[nngreen]

Do you have any photos of the hook-up between the charge controller and the solar panels?

[jolshefsky]

I think you did a good job on the construction, but it's not an ideal solar system. You definitely need a fuse on the battery pack. If you were to short out those 2ga power wires, those batteries would kindly dump close to 1000 amps or 12,000 watts as fast as they could. In other words, huge sparks, red-hot wires, and a fire. It would be very bad. Since these are expensive batteries, you'll probably want to maintain them as well to make sure they last as long as possible. Keeping them mostly charged all the time is a good start, but you should also check the water levels regularly. Also, you should wire up the outputs from opposite ends of the batteries. This balances the load to each battery. Right now, battery #1 will discharge more than battery #3 because of the slight resistance of the wire between them. By hooking the negative output to battery 3 and the positive to battery 1, the resistance to each battery is 2 lengths of connector wire (red+red on #3, red+black on #2 and black+black on #3). As you've noted, the solar panel is undersized for the battery pack. I'd guess you have about 2000 watt-hours of battery capacity and 60 watts of solar charging capacity. It's not bad for "occasional," emergency use. If the batteries were dead, it would probably take a week's worth of sunny days to recharge them. I'd also be concerned about moving it around with the tote you've put the batteries in. Is it really strong enough to pick up? I imagine those batteries weigh about 100 pounds or so and it would be very bad if they fell out the bottom of the tote when you picked it up. But, like I say, the wiring is all clean and it looks good. Using a charge controller was an important factor as well. Hopefully you'll get some good use out of this.

[AndrewM]

Great suggestion! Can any one explain how I could attach a fuse to this system? Is only needed or is one needed for each battery? Little in the dark here, but it seems like this setup needs this. Thanks!

[blacknkhak]

jolshefsky is so very right about that fuse. there is something so very not funny about crispy black wires surrounded by a cloud of smelly thick smoke.

[Merakesh]

Only using a small amount of power from the batteries could sulfate the plates(Battery gets a memory), and make them useless beyond the small amount you've used them, you should let them discharge almost fully once inawhile before recharging them.

[Derin]

Same for NiCd batteries,although you shouldn't keep lead acid batteries uncharged.

[Mr. Chicken]

Thanks for the comments. I didn't even thick about the wires shorting out. I'm also going to change where the inverter connects to the batteries. As for moving them around, they are pretty heavy. I hadn't really planed on moving the tote around once it was set up. Even if it was strong enough to hold the batteries, I cannot lift it with them in there. So, for now, I have to take them out and move everything separately.

[siuengrmatt]

I am in the process of researching solar power systems and wanted to know if this set up would fit my needs. I currently rent a house and do not want to hard-wire solar panels but still want some advantages of solar power. I live in a renovated row house and have window AC units (very inefficient). My intent is to set some small panels on the roof of my kitchen (south facing wall) and run the cable about 20 feet to my basement. I would like to run 3 power cords: (2 to my window AC units that are on the same back wall as the kitchen and 1 to the first floor to my TV (plasma which uses a lot of energy) and dvd/satellite box.) I would like to run these units as much as I could and then plug back into my wall outlets when the power ran low to recharge. Is this possible and would this system work?

[Tyrannous]

An issue everyone should investigate is a Pure Sine Wave inverter for higher quality electronics for a cleaner electric signal. For laptops, and tvs, the problem is the pure sine wave are twice or more expensive than the cheapo ones you will see all over, because they dont do as well of a job converting the energy, (i think)
this is the one im looking to buy

http://store.altenergystore.com/Inverters/Off-Grid-No-Utility-Needs-Batteries/1000-to-1999-Watts/Go-Power-1500W-SW1500-12-12V-Inverter/p584/

[Tyrannous]

more info on that

http://www.roadtripamerica.com/dashboarding/Power-Inverters.htm

[Mr. Chicken]

Could it work, yes. However, AC units and plasma TVs are huge energy hogs. You would need a pretty high wattage inverter to run them, a larger battery bank than what I have to run them for any length of time, and a larger solar panel array to get decent charge times. If you size the system for your power needs you should be fine though. You would just need a larger system set up.

[finfan7]

Speaking of AC units, how hard would it be to set up a system that would use solar energy when possible but switch to grid power when the sun went down and the batteries ran down? Would the setup be much different from this?

[alloqba]

Remember - when you want to recharge the batteries mind the temperature - they produce a lot of heat while charging.

[alloqba]

Sorry, I forgot the point - maybe drill some holes or put a small fan with switch - on for charging, off for using.

[renet123]

Biker 74 is correct - but for this simple case parallel battery setup is the best choice. The rule of thumb would be that parallels keep the same voltage, and combine the amp hours of all the batteries. A series battery setup does not combine the amp hours, but combines the volts. In this case you are trying to squeeze as many amp hours as possible before the batteries lose charge. Curious that you left out photos of how you wired the multiple solar panels.. and wondering how that update is coming. - how long is it taking your solar panels to recharge the batteries? how many sun hours are you getting? How long is the lamp and/or laptop lasting on all 3 fully charged batteries?

[basmith526]

Your instructions were well written and the pictures did a great job showing what to do.

[ScottSEA]

I think your best investment for improving the ROI on this setup is to get those panels in full sun. You might consider rigging them to mount on the railing, or over it.

[Mr. Chicken]

This is very true and while I do agree with you I feel it's best to avoid the wrath of the apartment complex while I'm here. But, once I get a house they will be in full sun and the panel array will get much, much larger.

[wilbanba]

have you thought of cross bracing the panels and mounting to a heavy duty photo tripod from a 2nd hand store? that way you can get elev, pan and tilt without attaching to a building. fwiw thanks nice work here.

[ArmChairQB]

Might Try a Drawing table as a mount, but might take up too much room.

[wilbanba]

i would also plumb a ballast below the tripod/panels to maintain stability -- read: panel + elevation = sail!

[buildem4me]

Aren't you concerned about hydrogen gas buildup inside of the container???

[jeffreystylus]

This is a good instructable. One detail I might point out however is that you have 2 gauge wires interconnecting your batteries but have 4 gauge wires running to you inverter. You need 2 gauge wires throughout this circuit. If you are pulling a full load (100 amps) to the inverter the 4 gauge wire is under-rated and might get a little toasty.

[DarthFader]

Great! Check out Homepower.com for information on projects like this.

[steadmanjon]

Great job. You explained it very well.

[KrstnDiane]

I really appreciate this post. My husband and I are in the process of buying a motorhome and while it has electrical set up in it, it doesn't have batteries or any other power source without pluging in to a hookup. I want to outfit the unit so we can camp off the grid... The wiring of the batteries and inverter is something I have been looking for online for months, but I'm not sure that we are going to go with a solar panel. We plan on buying a generator (mostly because there's an air conditioner in the unit). Would hooking up a generator be the same as a solar unit? Do you know enough about it to have any advice? Also, if you have your generator running, is it possible to charge the batteries and run the system off the generator at the same time? Just some questions...

[Mr. Chicken]

If you get a battery charger you could charge them off the generator. But this seems inefficient to me. You loose a bit while charging and then some more while running an inverter. Batteries/inverters aren't very good for running high power appliances like AC units either. I tried running a 1200W hot plate off mine a while ago and it shut the inverter off. Just couldn't handle it. I need to get a higher rated inverter. You should be able to charge the batteries and run what ever else you want at the same time so long as your generator is rated high enough to run everything. I'd recommend connecting batteries to the engines alternator, or adding a second alternator to the engine and charge them that way. Then, when ever you drive, the batteries would charge. Should be able to power lights and other simple items with out to much trouble. Hope that helps... good luck.

[spangewest]

Is it possible to capture, and use the hydrogen to power fuel cells?

[Merakesh]

Google the term "electrolysis".

[Q5Quint]

From your picture it looks like your panels are getting shaded~ make sure they are getting 100% full sun between 9am and 3pm to maximize your energy intake. If even a small part of the panel is shaded from the sun the whole panels outputs drops a tremendous amount. Mirrors will increase the panels output but the increased heat and radiation could shorten the life of your panels. A small hole near the lid would allow most of the hydrogen to escape~ hydrogen rises VERY fast and will get out of any openings pretty quickly~ look at the venting system on your car's bettery. Some use small computer 12v fans but as long as your container is NOT air tight you should be ok. There is more danger from overcharging the batteries and having boiling battery acid spill out into your plastic non-acid resistant container.... just be careful ;) Nice work! -Quint www.asuses.net

[Mr. Chicken]

Yes, the panels get some shade. Unfortunately, I'm in a second floor apartment so I don't have many options. I even tried putting the panels inside on the windows but couldn't get the panel angles to work out right. So, for now, the best I can do is on the deck and get a little bit of shade.

[talonsblade]

From the look of the sade it looks like they are behind some kind of railing. you could build your own rack to mount them to the railing. this would get them out directly infront of the sun.

[Electrolight]

Does anyone know how many amp/hours this batterie has?

Optima Battery 9051-160: Battery, YellowTop, 12 V, Deep Cycle

Link:
http://www.amazon.com/exec/obidos/tg/detail/-/B0006I2QYY/qid=1100621096/sr=1-1/ref=sr_1_1?v=glance&s=hi

It runs for about 245 dollars. And it says on a website that it has a 1125 amp capacity. Is that 1125 amp/hours?

I want to know so I can compare it to Mr Chickens batteries.

Thanks

[Mr. Chicken]

It appears they are only a 75 amphour battery.

http://www.jegs.com/webapp/wcs/stores/servlet/product_10001_10002_84580_-1

[Electrolight]

Ok thank you I guess I didn't look hard enough. Electrolight

[saintchuck]

What would be the feasibility of using a similar system sans the inverter to run a 12v lighting system? Have been considering setting up a led lighting system in the apartment and this would be perfect for powering it.

[Mr. Chicken]

That would probably work out pretty well. Then, you wouldn't be loosing any thing in the inverter conversion. I think I heard some where you loose like 20% of the power to convert from DC to AC.

[podup365.com]

If you used a 12 volt auto charger for your laptop (or cell phone), you could use the DC from the batteries without converting it to AC. Then you would also eliminate the loss from your laptop's power supply converting the power back to DC to charge your laptop battery.

[Hatake Kakashi]

Where do get that huge panel????

[Mr. Chicken]

I got these used off craigslist. I'd also recommend looking on ebay also.

[2dMaxf]

This is too cool, but I have a few questions.I thought about this when the light company started to raise the rates.I had a fridge in the garage, cold beer is good once and a while, and it used up a lot of edison. I'm thinking of using something like this but on a little larger scale. Solar panels come in a variety of sizes. What are yours rated for? There are a lot of different size converters out there also. Which size are yours? Harbor Freight tools carries at least three sizes. Did the charge controller come with your panels? I plan to combine mine with wind turbins for the night, it's always windy where I live at night. I hope to be able to tell the light co. to stick it!

[Mr. Chicken]

My solar panels are 60 watts total. And, after having this system up for a while I can safely say they are undersized (but this was originally intended to be used during power outages) . My inverter is 1200 watts. Witch is doing a great job with everything thus far. However, given the chance to do it over I'd probably go with a 2400 watt or greater inverter. I got the charge controller when I bought the panels. But, I got them used and the person I got them from didn't need it any more. I don't know if you can get them with panels or not. I've also thought about adding wind generators to my system. Just haven't decided if I will by the windmill or design/build one on my own. Good luck with setting up your system.

[pmartinez]

Great instructions, I was waiting for something like this. I am very mechanical incline; however; when it comes to electrical things I'm as dumbed as a door knob. With that said here goes the dumb question: Can you please instruct me how the solar panel connects to the whole battery setup. Thank you

[Mr. Chicken]

These are actually 4 individual panels connected together. But basically all the positive outputs are connected together and all the negative outputs are connected together. From there, the wires are connected to the charge controller. The controller is marked for which wires are for the panels. The charge controller has a second set of wires to connect to the batteries. If you look at the picture of my charge controller you will see the two sets of wires. Hope that answers your question.

[pmartinez]

Thank you, With your permission I will print and save the instructions Thanks

[jwater7]

Very good instructable! I'd like to do something like this someday when I get some money to play with. I'm a little worried about the hydrogen gas buildup and acid spills, aren't you supposed to keep batteries outside?

[carpespasm]

that was what i was thinking. It would be a good idea to keep the battery bank outside so you don't wind up with a hydrogen buildup inside. Aside from that this is a good instructable. Hope you get plenty of use out of that setup!

[Tom_n_6bzone]

I have almost the same setup in my shed for powering a light and a fan (both 12 volt d.c.). An inverter is nice but its not as efficient as running dc appliances when possible.

[agatornz]

in australia and nz at least conecting your system to the mains becomes exspensive as they make certian requirements of you to do so....

[agatornz]

now what i would like to see is somebody that can make a simple installation that allows us rental dwellers to run our lives off solar power with out having to hard wire any thing to some one elses house - wether it means we run our own DC wiring tacked to the wall and convert to dc... then turn off the mains at the box until we need extra power or....

[Oorspronklikheid]

you don't need to turn off the mains and you can connect the solar system to your mains and not use any batteries

[p0g068]

thanks for sharing I work on a boat dock and some of the boat owners dispose of perfectly good marine batteries regularly, maybe something some of you want to check out in your home towns thank you again!

[nireves1]

@jolshefsky thanx dude! finely some useful information on solarpower!

[nireves1]

but is't al this in the manual you got when you buy the set?!

[robbtoberfest]

Great instructable; I've been waiting for someone to do this to see all the components involved.

[joegeek]

OUTSTANDING INSTRUCTABLE!! TY Living on a sailboat for many years I've seen these systems used quite alot with "Deep Cycle" Batts and the applications are VERY practable. Great suggestions by Jolshefsky and Gkimer2 please take them as POSITIVE. My only 2 cents would be to add Battery Isolators in case one battery went bad the whole system wouldn't be overcharged because of a bad battery. I used one on boat for a duel battery system - West Marine has some, and I think their catalog has a diagram or rough schematic for their use in a multi battery system. Thank You Mr. Chicken :-) bak buk buk bukgeeeek

[shooby]

Since you're already dropped $650 on this, you may want to consider installing a small mirror system, to increase the light incident on the panels during an overcast day. Could shave a day or two off of the recharge time.

[uguy]

Excellent, well done ible. Thanks for sharing with us.