Building a micro solar generator

This is a little solar generator i made for camping and fishing. It could come in handy in a power outage as well.

supplies needed:
1.26w weather proof solar panel $30.00 (cabelas)
12v 7.5amp rechargeable sealed lead-acid battery $30.00 (radioshack)
12v socket $11.00 (walmart)
cooler $8.00 (walmart)
nuts/bolts $2.00 (walmart)
wire plugs $2.00 (walmart)
super glue $1.00 (dollar store)

TOTAL: $84.00
w/tax around $90.00

tools needed:
drill
utility knife
screw drivers
wire cutters

Step 1: Cutting wires and holes

I made no exact measurements for wire length, just guestimation. using a tape measurer i centered the panel on the lid and used the 12v socket for the hole pattern on the side. On the lid I drilled 5 holes, 4 for the panel to mount to the lid and 1 for the panel wire.

Comments

[michaelb2]

12 volt batteries need a head voltage to charge fully ( you car charges at 13.5-14 volts)
So it will not over charge if the proper panel voltage is applied. The panel likely has a rectifier so that it does not discharge when the sun goes down.

[dualqual]

Very good project! I was a bit concerned about battery voltage back feeding into the solar panel. Then I went to Cabelas web site and found out that the panel has blocking diodes. Nice Job!

[bigcosmos]

red is my love color

[whrockshalo]

i know that this thread is old, but i really like the idea. the only question i have is how you keep the battery from being overcharged

[jdbee]

would this run a crockpot?Mine is 120v, 180 watt... on low
still looking for an inexpensive way to run one in an emergency.
Is there a way to hook up 2 of these to give double the power?
janei

[butchie50]

Would this run an incandescent lignt bulb for a few hours per night.. Just enough to provide light and heat for my chickens. I already have the ice chest and few non-working solar lights and solar spot lights I got from Wal-mart and Harbor Freight. Except for the batteries that seems to be the most expensive part of the project.

I also have working solar lantern (uses L.E.D. bulbs) that I got from tractor supply for $25 + tax that has a 5.5 volt panel. I don't have (or really want) electricity per se, but don't want to run a propane heater to the chickens. Incandescent bulbs provide heat, in fact I think they provide more heat than light.

For about $80 I can put a deep cycle marine battery on lay-a-away at Tractor supply. 12 v. but I'm not sure about the wattage or the ampage.

[how to make a solar panel]

Thats great using the cooler i must try that.

[sscottE]

Will this unit power a small space heater? Like the ones you find a walmart that can fit on a desk or heat a small room? Thanks....

[themike]

A space heater requires a considerable amount of power (most small units start at 500-1000 watts). A small system like this would not have nearly enough capacity. From the hugely inadequate solar panel rating of sub-two watts, it is evident that such a heater could not be run from solar power alone, but you'd have a hard time even running it from the battery. A 500-watt, 120V space heater draws around 4 amps from the wall. If you want to run the same heater from an inverter, the wattage will be the same, but since the voltage is reduced by an order of magnitude, you will now need 40 amps from the battery. Most batteries' amp-hour rating is based on a so-called 20-hour rate, or how much capacity the battery has when discharged over 20 hours. For this battery at 7.5Ah, the 20-hour current rating is about 400mA. At 100 times this load, expect battery capacity to drop by a couple to several Ah, which cuts your runtime - if it is able to run the load at all - to ten minutes or less. So in summation: no, this system would not run a space heater. It's much better suited to small loads. To the author, nice packaging, though.

[hleon]

This is a cool project. I velcroed my batt to the cooler, as that kept it from sliding when carring. The solar panel charges slowly, needs about 2 weeks of full sunlight to be recharged. I love it, thogh. It powers everything in my treehouse (lights, fans, etc.) I am going to build an air conditioner this summer, so keep your eyes peeled!

[blacknkhak]

i did something identical to this with a trickle charger panel , a blemished diesel battery from a local factory outlet and an old 400 watt inverter. i put the panel,inverter and solar panel on a luggage cart and park it in the sun . When I need it i drag it to the spot and have power on demand. the only improvement mine needed was a way to charge it from standard household outlets. those blemished/ factory seconds batteries are easy to get from battery outlets like interstate battery etc. the amp hour ratings are pretty good but the sloshy old cells can be leaky. anyway the luggage cart was sort of tippy and that big battery tended to want to sort of tip over and kind of got leaky.in an acidly sort of way. so any way wheels are nice to have on a unit like this .

[crapflinger]

pardon my ignoance...but...is the lamp (in this scenario) charging the battery that it's plugged into via the solar panel? obviously your concept isn't to power the lamp right? it's to charge much smaller devices etc?...just perplexed

[blacknkhak]

yes this is a divine example of hyper efficient design, a lamp that powers its own battery!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[zootboy]

The lamp was just a test. It was not meant to power the solar panel.

[Full Frontal Graphic]

LOL, that's a cool idea, run the lamp off of the solar panel that is being charged by the lamp. If you get that to work, you have yourself a nice perpetual motion machine.

[-Aj-]

haha yes, you would. but just the fact that its a lamp instantly means that would fail, being what, 20% efficient maybe? smae as the solar panel. + wiring resistance + ect.... lol unless its all super conducting and you have a way to ensure that every single electron produces a photon and that every photon hitting the solar panel excites atleast one electron.. then unfortunately it wont work. electronics are just waay to lossy at the moment to get perpetual motion with them, unless you do whip out some serious funky stuff with lots of wire coils, big magnets and atLEAST a half dosen glowing crystal thingies. then nup NOOO WAY will it happen :P

[dontcare]

would this charge a 12 volt battery? i know someone who wants to build a solar panel system that would...

[mas9779]

should but take forever try looking for larger panel

[Morgo]

are there any battery types outside of the bulky lead acid batteries that you could get a decent and lasting charge out of but with a lower weight/size?

[fkuk]

would it be feasible to run something like a small tv off that with a power inverter also do you have a wiring diagram because I don't get the picture

[rgfoster]

Here is a nice start for someone wanting to build something like this. Coleman waterproof jumpstart. Has an 18 Ah battery and a nice waterproof case. My local Pep Boys had it on sale for $35 last week, may still be that price, regularly $50. Add one of the battery maintainer solar cells that plugs into the car's cigarette lighter (about $20 from Harbor Freight), and you are done.

[blodefood]

Get the cooler at Value Village, Goodwill or other thrift store for half the price. You'll save plenty and you can head over to Canadian Tire or Zellers for the rest if you don't like to go to Wal-Mart. But like everything else at the thrift shops, you'll have to keep an eye out for them. Radio Shack is no longer in Canada. Go to The Source stores.

[curlyfry562]

I am starting work on a larger version of this that I can leave on my roof for several days a t a time and then lug it down and power something. I don't want to have to mount anything to my roof so the batteries are what keep it anchored because theyt are so heavy. I am also going to use a charge controller and a larger inverter. I will post whaen finished.

[SacTownSue]

Very handy for an emergency if not sooner. How about something to prop the lid up for those days when the sun is low in the sky? I may do this project. I don't think I'll bolt the solar panel down tho in case I want the panel outside while I'm inside.

[jdkmetal]

Have you thought about flexible solar panels?? I'm sure they are a bit more money but could be fun......

[robbtoberfest]

4 thumbs up, this is great. I'm thinking a fold out panel system for more juice would be cool.

[robbtoberfest]

Oh yeah, this is fun; bicycle pedals on the side hooked up to a built-in generator for a little more boost.

[RoDuS1488]

Well every one, I have a new micro-gen design idea that will be much better. it will cost a few more dollars to build (weather proof sealed case, larger panel ). I have no need for 2 of them so I'm going to put this one on eBay around 3/27/07, if I can get $100.00 I'll be happy with that. There are also 2 more larger versions in the works (prob not backpack friendly). I ordered a 10 and a 20 watt panel today.

[SarahKB]

the lamp is powering itself? cool.

[RoDuS1488]

Thanks every one for the positive feedback! The compact florescent was used just to test the micro gen out., It would prob only last about 3 hours and yes LasVegas you are correct, back current protection is built-in. The led lamp in the accessories picture should run for about 8 days 24/7 before draining the battery. I have been thinking of adding a analog volt meter w/test button and a second battery in the near future. The only concern is the weight factor of the second battery, i want to keep it backpack friendly. There's also a battery harness in the works to keep it from sliding around. One regret i have was not thinking and buying stainless steel nuts/bolts.

[volvoturbo]

Are you sure that a 1.26 watt panel is enough to give the battery a charge? Otherwise, very cool. Could be expanded upon to become an emergency power supply for hurricanes and power outages.

[trebuchet03]

12V @ 1.26 watts is about 100mA. It will give a charge... it's just a mater of how long it takes to do so ;)

[Tool Using Animal]

75 hours or about ten days. Efficiency could be improved with the inclusion of a cold six pack

[trebuchet03]

That would surely make the time pass faster :P

[indyguy]

Great instructable! Instructions are very clear and basic, and you even gave examples o ways to utilize the generator for other appliances.

Makes me think a lot of a link I saw recently to build a solar generator for less than $300:
http://www.rain.org/~philfear/how2solar.html

In the above link they emphasize deep-cycle batteries. Depending on the size of said container/cooler, I would think such a battery would work great in your instructable.

Very nice!

[brianf25]

'Cool' idea using the cooler. how long will that battery last running the florescent bulb?

[acaz93]

it would be a neat idea to add a small rectifier , so the energy won't go back to the panel happy instructabling !

[LasVegas]

I'm sure that weather-proof panel already has back current protection built-in.