12V solar panel system

Anything electric, AC or DC

12V solar panel system

Postby vitya-velik » Mon May 02, 2016 9:49 pm

I decided to go with just 12v 35amp hour batteries and 100W solar panel as my only power supply for my teardrop.
I think I'll just buy a kit from ebay with the charge controller and everything.
I am trying to power 3 led lights, 1 fan, a couple 12v sockets for power and a couple usb ports.
Should I use 12 or 14 gauge wire? What kind of of circuit breakers?
I want to order all this online. Can someone come up with all the components that I'll need. Thank you!

Sent from my LG-H343 using Tapatalk
vitya-velik
Teardrop Advisor
 
Posts: 50
Joined: Sun Oct 25, 2015 11:07 am

Re: 12V solar panel system

Postby noseoil » Tue May 03, 2016 7:40 am

You should be fine with that system. I would gauge the wire to the load, plus a bit more. The LED lights draw very little current, so small wire is good (14-16 ga). The USB ports will not be drawing much current either, so small wire again will work. The fan I run (MaxxAir 10 speed) uses about 4.7 amps on high, but we don't run it that fast. 16 ga is good here as well.

The main draw will be the 12 volt sockets. They can draw up to 15 amps each, so a heavier wire for each one would be best. Wire is figured as a function of load & distance for 12 volt stuff. Here's a good chart to look at for your stuff. http://www.rcgroups.com/forums/showthread.php?t=2132883

I would just look online for a 12 volt fuse block & go to a home center store to get a grounding buss to use to tie the grounds together (it's just a metal piece with some holes drilled in it). Basically, you are running the positive battery lug to the connection at the fuse block for feeds & the negative post to the ground strip. Remember, when selecting fuses you are protecting the wire that runs the circuit. Run the hot out & the ground back from each circuit.

I would use 15 amp fuses for the 12 volt outlets & 5 amp fuses for the other stuff. 5 amps is OK for the fan, typically.
Build log: viewtopic.php?f=50&t=60248
The time you spend planning is more important than the time you spend building.........

Image
User avatar
noseoil
1000 Club
1000 Club
 
Posts: 1278
Images: 66
Joined: Sun Apr 27, 2014 8:46 am

Re: 12V solar panel system

Postby Shadow Catcher » Tue May 03, 2016 9:33 am

A 35 AH battery give you very little usable power to keep it above the 50% state of charge necessary to give it a long and happy life.
http://www.solar-electric.com/deep-cycle-battery-faq.html
User avatar
Shadow Catcher
Donating Member
 
Posts: 5611
Images: 192
Joined: Sat Apr 11, 2009 8:26 pm
Location: Metamora, OH
Top

Re: 12V solar panel system

Postby bonnie » Tue May 03, 2016 9:36 am

Shadow Catcher wrote:A 35 AH battery give you very little usable power to keep it above the 50% state of charge necessary to give it a long and happy life.
http://www.solar-electric.com/deep-cycle-battery-faq.html


I'm looking at this too. When you have 2 wired to make one 70 AH battery (lifting one 70 AH would be impossible for me) would the same hold true?
Remember, the turtle won. :)
User avatar
bonnie
Donating Member
 
Posts: 1346
Images: 107
Joined: Sun Jul 24, 2011 4:14 pm
Location: Belleville IL
Top

Re: 12V solar panel system

Postby vincigj » Tue May 03, 2016 4:32 pm

I use a 32ahr battery. Porch led lights, cabin double led same as kitchen light. Fan and incandescent reading lights and kindle and cell phone charging. Charging through a 5amp charge controller with 20watt panel. No problems. All depends on how much load and how long you use it between charges. Possible but worse thing one can do is as a last resort charge using car.
vincigj
Teardrop Advisor
 
Posts: 69
Images: 8
Joined: Tue Jun 14, 2011 8:29 am
Location: Eastern CT
Top

Re: 12V solar panel system

Postby noseoil » Wed May 04, 2016 7:43 am

I think 2 of the 35 AH batteries makes a lot of sense in a trailer. Weight is one consideration, as was mentioned above. With the AGM wheel chair batteries, you can take them down below 50% regularly & not hurt them at all. A large battery can just be too heavy to handle for many people.

Let's say you have a fan running & are reading at night. The fan will be on low, usually, so let's say it draws 1.5 AH when running, the lights might total another .5 AH. You have a total of 2 AH in this case. You fall asleep with the lights on and the fan running!

If this goes on for the entire night, let's say for 10 hours, it will total 20 AH in the morning. With 2 of the 35 AH batteries, it would mean you have used up about 57% of the total battery capacity. With a 100 watt solar panel, it would take about 3 hours to replace what's been used. No problems!
Build log: viewtopic.php?f=50&t=60248
The time you spend planning is more important than the time you spend building.........

Image
User avatar
noseoil
1000 Club
1000 Club
 
Posts: 1278
Images: 66
Joined: Sun Apr 27, 2014 8:46 am
Top

Re: 12V solar panel system

Postby dales133 » Wed May 04, 2016 2:23 pm

What do you recon your tv consumes?
I was thinking of 100ah battery but im not commited to anything just yet
User avatar
dales133
4000 Club
4000 Club
 
Posts: 4570
Images: 1
Joined: Mon Oct 13, 2014 5:26 pm
Top

Re: 12V solar panel system

Postby bobhenry » Thu May 05, 2016 7:27 am

dales133 wrote:What do you recon your tv consumes?
I was thinking of 100ah battery but im not commited to anything just yet


http://energyusecalculator.com/electric ... isplay.htm

15 17 and 19 inch seem to be the most efficient. And in a tiny these are plenty large enough for viewing at 4-5 feet away !

So you should be able to run your 15" LCD tv for 3.33 days around the clock! :beer:
Growing older but not up !
User avatar
bobhenry
9000 Club
9000 Club
 
Posts: 9880
Images: 2280
Joined: Fri Feb 09, 2007 7:49 am
Location: INDIANA, LINDEN
Top

Re: 12V solar panel system

Postby noseoil » Thu May 05, 2016 7:46 am

The 22" uses just a bit more juice, but the real draw is the sound bar at 39 watts. Unfortunately, our sound bar has to run at 18 volts, so I use an inverter for power to the sound bar, TV & BluRay player. I figure with all of it up & running it's more like 80 watts with everything cranking. I guess I could use a meter to look at the actual draw, so I might do that at some point.

Still, a movie at night for 2 hours doesn't make much of a dent in the battery. It always charges back up the next day no matter what we do with the TV, fan, lights, stereo, etc.
Build log: viewtopic.php?f=50&t=60248
The time you spend planning is more important than the time you spend building.........

Image
User avatar
noseoil
1000 Club
1000 Club
 
Posts: 1278
Images: 66
Joined: Sun Apr 27, 2014 8:46 am
Top

Re: 12V solar panel system

Postby JaggedEdges » Thu May 05, 2016 9:14 am

Could probably run the sound bar off 12V but it would distort above about 2/3 volume.

Edit: Same might go for other things like TVs that have an external AC adapter, they "just" work if you don't have the volume or brightness too high. Notebooks can often run off 12V but they won't be able to charge the battery.

Edit II the re-editing: Though you know what, solar panel output probably climbs closer to typical notebook supply voltage in full sun in middle of the day, so you could arrange a tap before your house battery charge regulator, to hook up your notebook to charge. (Basically it's gotta get above what the notebooks own battery voltage is, plus a few percent inefficiency)
Jack of all trades, Doctor of rocket surgery and fellow of the noble college of shadetree meddlers. "in argentum tenax vinculum speramus"
JaggedEdges
Teardrop Master
 
Posts: 224
Joined: Mon Apr 06, 2015 5:32 pm
Location: Niagara Region, Ontario
Top


Return to Electrical Secrets

Who is online

Users browsing this forum: No registered users and 2 guests