Taperssection.com
Gear / Technical Help => Remote Power => Topic started by: beeco on June 06, 2011, 07:49:40 PM
-
So I'm headed to a festival next week and decided to upgrade the solar power set-up for our campsite. We have about 2 dozen folks camping with us and we try to light the camp site with LED party lights and provide a place to run a coffee grinder in the morning and phone chargers or even laptops during the day. My former solar panels, two cheapos from harbor Freight, weren't cutting it.
So this is definitely not a taping rig, but I thought you DIY-ers would dig the set up. I'm sure I could keep several 9v DVD batteries in rotation and fully charged with this but if you ever see me rolling all this crap into the tapers section, just shoot me.
Lying on my trailer is a new 85-watt solar panel. In front of that are two 86Ah gel batteries, stacked, and wired in parallel. The oversize milk crate has the controller and inverter, a "work light" (which used to be a solar sidewalk light), a 12v+5v usb outlet and an 800 watt inverter and power strip.
(http://i385.photobucket.com/albums/oo298/bevinowens/IMG_0217-1.jpg)
The up close. I tried to keep everything zip-tied up as neat as possible.
From the left: the 12v outlet with 5v USB (wired directly to the LOAD output of the controller for all day cell phone charging), the 15amp charge controller with incoming wire from the panels and outgoing wire to the batteries, a 4-outlet power strip and the 800watt inverter:
(http://i385.photobucket.com/albums/oo298/bevinowens/IMG_0219.jpg)
Of course you could recharge taping batteries all week off just the batteries and the inverter, but the panel brings it all up to 13.5v in one day after a pretty full discharge (like down to 11.7v) over night.
Too bad it weighs almost 150 pounds.
-
Nice!
sine you are not using the harbor freight panels any longer
what panel did you upgrade to?
thanx
--Ian
-
you might be ale to get a more efficient power inverter, which would help run time - but that's just late night talk... ;)
-
i just saw this on tv last night
http://www.goalzero.com/shop/p/79/Guide-10-Adventure-Kit/1:1/
it was $125 on tv
seems cool if you are going to be where there isn't wall power for a bit
charges the battery pack in 1-2hrs
charges rechargble aa in 1/2 hrs
works with usb and 12v plugs
the overall nice thing is you don't have to carry the solar panel with you, charge the little pack and away you go
-
http://411solar.net/Kyocera-KC85TEquivalent-Solar-Panel-85Watts-Bolt/M/B003ZUBIP8.htm
Is this it?
-
i just saw this on tv last night
http://www.goalzero.com/shop/p/79/Guide-10-Adventure-Kit/1:1/
it was $125 on tv
seems cool if you are going to be where there isn't wall power for a bit
charges the battery pack in 1-2hrs
charges rechargble aa in 1/2 hrs
works with usb and 12v plugs
the overall nice thing is you don't have to carry the solar panel with you, charge the little pack and away you go
Looks pretty neat but my experience from standard battery chargers is that they don't do too well and often harm the batteries.
-
Hi Beeco,
nice idea - I do similar stuff for the field day of our radio club. As an electronics engineer, I have some tips for improvement.
1) safety: please cover the battery terminals to avoid accidental short circuits. Also I cant see any fuses. Lead acid batteries of this size can and do produce immense short circuit currents and may explode due to overheating of the electrolyte when short circuited. Spraying sulfuric acid into a campsite is not exactly nice... And dont forget that lead acid batteries produce hydrogen and oxygen gas during charge. Keep them away from open fire and anything that can generate sparks. Do not charge them in an enclosed container. Best solution for storing the batteries would be your milk crate with a lid.
2) You connected the batteries in parallel with two cables. These have a certain resistance (in the milliohm range). Your inverter will draw about 80 Amps when going all out. Now the lower battery in your photo will deliver more power than the upper, since the cables increase the internal resistance of the upper battery. This leads to unequal discharge of the two batteries. Solution: connect the red wire of the inverter to the positive terminal of the upper battery. Now both batteries have one cable each as additional resistance in series and deliver equal amounts of power.
If you want to connect everything in a safe and idiot proof way, I can recommend Anderson power-pole connectors. They are the standard in the telecom industry for battery connections.
Greetings,
Rainer
-
Solution: connect the red wire of the inverter to the positive terminal of the upper battery. Now both batteries have one cable each as additional resistance in series and deliver equal amounts of power.
If you want to connect everything in a safe and idiot proof way, I can recommend Anderson power-pole connectors. They are the standard in the telecom industry for battery connections.
Great suggestions! = Resistance and inline fuses would certainly help to be more efficient and safer
thanx!
-
Is there any Solar controllers that work with LiIon or LiPoly batteries?
-
Thanks for the feedback, everyone!
Just back from Telluride Bluegrass Fest where we used this rig to keep about 30 cell phones charged all week, to light the party/picking tent every night and to run a coffee grinder in the mornings. In full sun, the 85 watt panel fully charged the batteries by noon, which was amazing.
To answer Ian's question, I ordered the solar panel from UL Solar in Las Vegas. They sell them on eBay but I ordered the same panel for the same price off their website, and also ordered a 30-ft pair of MC4 cables so I could have flexibility in positioning the panels in the sometimes shady campground.
The Kyocera panel to which H2O posted a link is priced at $425. UL Solar's 85watt panel was $195, including shipping. There's probably an efficiency difference between the brand name panel and the no name Chinese stuff, but it worked well for me last week. The 30-ft MC4 cables ran me another $40 or so.
http://www.ul-solar.com/ (http://www.ul-solar.com/)
Ian, can you recommend a more efficient inverter? The one I'm using is standard crap from the Pep Boys, so I know it's creating some drain by itself. Had no idea I could find one that's more efficient, but I'd like to do that.
For Kleiner Rainer, thanks for the safety suggestions. The whole rig was covered with a tarp all week to prevent it from getting wet. But covering the terminals sounds pretty necessary. Thankfully we didn't have any shorts last week and very little moisture (until we woke up in a inch of snow Monday morning!). Would gaffers tape do the trick or should I be using something more substantial to cover those terminals? Also, where would you insert a fuse in line and what amperage fuse should I be using? I wanna get this rig totally dialed in. I'll research the Anderson power pole connectors for sure.
And thanks for the suggestion about connecting the positive clamp to one battery and the negative to another. D'Oh - I shoulda figured that out myself.
Really appreciate the input, folks. Happy taping this summer!
Bevin
-
Bump...
Getting ready for my big festival trip of the summer so I'm bumping this back up to seek advice from folks with more knowledge than me...
Based on a recommendation above, I bought a fuse holder to insert a fuse into the system for additional safety. Gonna upgrade to a new battery(ies) as well.
It's my understanding that the solar charge controller has some sort of circuit breaker/overload protection, and that the inverter also has a built in fuse.
So if I'm going to insert an additional fuse in line somewhere for short circuit protection, where is the best place to locate that fuse? Maybe in between the batteries? Or in between the battery and the inverter? And what size fuse? I have an automotive-style blade fuse holder and I was thinking 5amps would be about right. If I'm drawing 5 amps off of a battery via an inverter, then I'm probably running to much load on the system anyway. Thoughts?
Charge controller features were stated like this, so I wonder if I really need a fuse:
Overload protection (automatic restoration)
Overcharge protection
Short circuit protection (automatic restoration)
Thunder protection
Reverse discharge protection
Reverse polarity connection protection (automatic restoration)
Reverse Polarity Protection for Battery
Reverse Polarity Protection for Solar panels
When the current of the load exceeds the rated current of the controller, the controller will activate the protection mode and lock up.
When the load short circuited, the controller will activate the protection mode and lock up.
Any advice is greatly appreciated. Wanna keep it simple and safe. Thanks!
-
To increase efficiency of the system you need to do two things:
- cut a wedge for each side that holds the panel at 40 degrees which is ideal for Colorado (in Louisiana its 30 degrees of pitch)
- attach a compass to the panel and aim it 180 degrees aka due south.
-
You could also make it the wedge adjustable with self leveling feet on each corner of the wedge/frame. that way when you head north or south you can adjust the angle for optimal performance.
-
If anybody else is thinking about doing this. I highly recommend making an adjustable tilt rack for the panel to sit on. Every latitude has as different angle to set your panel to. If you click on this link and then select your state, then closest city, you can get a report of the ideal angle for your panels.
http://rredc.nrel.gov/solar/calculators/PVWATTS/version1/
so for Boulder its 40 degrees of tilt
and for further south around Alamosa, its 37.5 degrees of tilt
So when you travel with your festy solar system you can set it to the correct tilt.
-
Excellent info - thanks! I hadn't thought about the specific angle for aiming the panel although of course it needs to be pointed at the sun. It'll be set up in a sometimes shady campground and will need to move the panel around a couple of times during the day. The wedge you describe would help keep things efficient as the panel moves to avoid shade.
Cheers
-
no problem. I work for a solar company so I figured I could help when I saw your post. Great idea btw. I am going to have to do something like this for my pop up camper.
-
If anybody else is thinking about doing this. I highly recommend making an adjustable tilt rack for the panel to sit on. Every latitude has as different angle to set your panel to. If you click on this link and then select your state, then closest city, you can get a report of the ideal angle for your panels.
http://rredc.nrel.gov/solar/calculators/PVWATTS/version1/
so for Boulder its 40 degrees of tilt
and for further south around Alamosa, its 37.5 degrees of tilt
So when you travel with your festy solar system you can set it to the correct tilt.
Hey Louie, are those degrees of tilt calculated for permanent installs? If so I'd image they may be a compromise between summer and winter declination, maybe favoring winter angles for more efficiency in those less solar energetic months? If that's the case, then less tilt for a temp summer setup might be optimal, especially up North. Yeah I know, splitting hairs and all that. Just currious, you know better than I.
-
If anybody else is thinking about doing this. I highly recommend making an adjustable tilt rack for the panel to sit on. Every latitude has as different angle to set your panel to. If you click on this link and then select your state, then closest city, you can get a report of the ideal angle for your panels.
http://rredc.nrel.gov/solar/calculators/PVWATTS/version1/
so for Boulder its 40 degrees of tilt
and for further south around Alamosa, its 37.5 degrees of tilt
So when you travel with your festy solar system you can set it to the correct tilt.
Hey Louie, are those degrees of tilt calculated for permanent installs? If so I'd image they may be a compromise between summer and winter declination, maybe favoring winter angles for more efficiency in those less solar energetic months? If that's the case, then less tilt for a temp summer setup might be optimal, especially up North. Yeah I know, splitting hairs and all that. Just currious, you know better than I.
yep. for fixed installations so it is an average for the whole year. if you hit the calculate button based on your system it will tell you the output based on the month. once you know that you can try increasing or decreasing the tilt to show what the effect is on the the production for the month in question.
-
the bottom line is anything is better than it laying flat.
-
the bottom line is anything is better than it laying flat.
....or upside down.