FAQ:Solar Panel without the Technical Stuff

Anything electric, AC or DC

Re: FAQ:Solar Panel without the Technical Stuff

Postby MtnDon » Sun Nov 23, 2014 3:34 pm

The battery tender is not really needed, unless you park the trailer in a garage or under cover, The PV panel and CC should be all that is needed to keep the battery charged fully. A battery tender is not much use for actually recharging a depleted battery, but you may already be aware of that.
Our 6x12 deep vee nose cargo trailer camper conversion... viewtopic.php?f=42&t=58336

We have a small off grid cabin we built ourselves in the NM mountains; small PV solar system; 624 watts PV, Outback CC & inverter/charger ... http://countryplans.com/smf/index.php?topic=2335.0
User avatar
MtnDon
1000 Club
1000 Club
 
Posts: 1939
Images: 6
Joined: Sun Aug 19, 2012 10:57 pm
Location: New Mexico

Re: FAQ:Solar Panel without the Technical Stuff

Postby MtnDon » Sun Nov 23, 2014 3:37 pm

BigBlueToe wrote: The charge controller has a place on it for powering lights (it cautions to use low power.) Is that where I draw the power for all my stuff? I was thinking it made more sense to get the power from the battery, but the Renogy how-to videos talk about getting power for lights off the charge controller.


The load terminals will have a maximum load spec'd; maybe the same as the amp rating of the CC, maybe less.. Stay below that and all is fine. By low loads they mean, do not connect and inverter there.
Our 6x12 deep vee nose cargo trailer camper conversion... viewtopic.php?f=42&t=58336

We have a small off grid cabin we built ourselves in the NM mountains; small PV solar system; 624 watts PV, Outback CC & inverter/charger ... http://countryplans.com/smf/index.php?topic=2335.0
User avatar
MtnDon
1000 Club
1000 Club
 
Posts: 1939
Images: 6
Joined: Sun Aug 19, 2012 10:57 pm
Location: New Mexico

Re: FAQ:Solar Panel without the Technical Stuff

Postby felixx » Fri Jan 02, 2015 1:58 pm

Is this a good buy?
Image
thats about $87 US

I will be running LED Lights and maybe a couple of PC fans only
felixx
Donating Member
 
Posts: 644
Images: 22
Joined: Sun Nov 30, 2014 3:01 pm
Location: Christchurch, New Zealand
Top

Re: FAQ:Solar Panel without the Technical Stuff

Postby bc toys » Wed Feb 18, 2015 12:45 pm

Ok its time I want a solar panel this is what I want to do with it charge 1 battery, run D/C lights, run D/C fan, and watch a auto DVD player witch is D/C. So what size panel do I need I would be using it only when camping about 1 time a month in sunny area Nv Az and Cali All help would be grateful. Want to stay around 250 to 300 dollars area
bc toys
2000 Club
2000 Club
 
Posts: 2163
Images: 42
Joined: Sun Jun 28, 2009 2:45 pm
Location: LAS VEGAS NV
Top

Re: FAQ:Solar Panel without the Technical Stuff

Postby tony.latham » Wed Feb 18, 2015 2:26 pm

only when camping about 1 time a month


Don't take this as a smart-ass answer, 'cause it's not ment to be. When you say "1-time", how many nights are we talking here? Also how many amp-hours is your battery?

I use LED lights in my fixtures and they draw so little, I can't even measure the amperage. My Frantastic fan draws 2-4 amp/hours. My DVD player draws about 4 amps (and we seldom use it). My battery is a Group 27 that when new has about 50 useable amp hours... I don't plug my folding 60 watt panels in until about day three and that's probably 'cause it makes me feel good. When I park; my battery is charged up and by the time I'm home, it's recharged.

Having said that the panel has been maintaing my battery all winter. I stole bosborn's folding panel DIY concept off his website here and have about $125 into them:
http://home.comcast.net/~bdosborn/Boxca ... Solar.html


Tony
Image
User avatar
tony.latham
Silver Donating Member
 
Posts: 2285
Images: 17
Joined: Mon Jul 08, 2013 4:03 pm
Location: Middle of Idaho on the edge of nowhere
Top

Re: FAQ:Solar Panel without the Technical Stuff

Postby bdosborn » Wed Feb 18, 2015 8:04 pm

bc toys wrote:Ok its time I want a solar panel this is what I want to do with it charge 1 battery, run D/C lights, run D/C fan, and watch a auto DVD player witch is D/C.


I ran the same loads easily off an 80w panel.

Bruce
2009 6.5'X11' TTT - Boxcar
Image
Boxcar Build
User avatar
bdosborn
Donating Member
 
Posts: 4214
Images: 450
Joined: Wed May 05, 2004 11:10 pm
Location: CO, Littleton
Top

Re: FAQ:Solar Panel without the Technical Stuff

Postby bc toys » Sat Feb 21, 2015 10:01 am

Tony 4 nights at a time Im looking at a 100w foldable unit, I'm not sure on that I'll look today and see got to go down to trailer anyway
Bruce thanks for responding
bc toys
2000 Club
2000 Club
 
Posts: 2163
Images: 42
Joined: Sun Jun 28, 2009 2:45 pm
Location: LAS VEGAS NV
Top

Re: FAQ:Solar Panel without the Technical Stuff

Postby Bill n Robi » Sun Mar 15, 2015 8:43 am

So here is a weird question.
I changed my mind a bit about my solar setup and was looking for some parts. I found, on only one web site, a grounding stake for lightning to protect your solar panels. I would think if there was that kind of storm I would pack up the panels just because of the wind and rain. Maybe if you had permanently mounted panels it might be something to get. In all reality it sounds like a scam as I have never heard of the issue or seen them for sale before.

Is this a real issue?

Bill
2015 T@G Max
2015 Toyota Tacoma TRD Sport 4 Door Short Bed
User avatar
Bill n Robi
Teardrop Master
 
Posts: 240
Joined: Mon Dec 01, 2014 4:32 pm
Location: San Diego, Ca
Top

Re: FAQ:Solar Panel without the Technical Stuff

Postby bdosborn » Sun Mar 15, 2015 1:55 pm

Nope. It might be something that would be useful for a utility size array but it's not going to do much for a single panel. Lightning protection systems actually draw strikes to the building they are protecting, the idea is to direct it to a low impedance path to ground. Unfortunately, lightning doesn't always follow the rules. I've seen a strike to a building that was right by a LPS rod. I don't think I'd want to be in a teardrop that drew lighting strikes to it!

Bruce
2009 6.5'X11' TTT - Boxcar
Image
Boxcar Build
User avatar
bdosborn
Donating Member
 
Posts: 4214
Images: 450
Joined: Wed May 05, 2004 11:10 pm
Location: CO, Littleton
Top

Re:

Postby Kaz » Sun Mar 15, 2015 3:36 pm

This is a good deal too. !00watt panel on a good day will get you a good recharge.You want to look for an MPPT type solar controller.

http://www.ebay.com/itm/100-Watt-12V-Mo ... 418019d07c
Kaz
User avatar
Kaz
Silver Donating Member
 
Posts: 217
Images: 121
Joined: Tue Sep 23, 2014 3:27 pm
Location: Hanson. MA
Top

Re: FAQ:Solar Panel without the Technical Stuff

Postby MtnDon » Sun Mar 15, 2015 5:57 pm

A single 100 watt panel won't gain much from use of an MPPT charge controller. IMO, not enough gain to spend the extra money compared to a PWM charge controller. Small solar systems can work well with PWM.


I would not bother with a ground rod on a TD or any RV for that matter. If it storms stay inside, especially if the unit has a metal skin. That will keep the lightning charge on the exterior skin. It would be interesting to see the ad and read how they are promoting it.
Our 6x12 deep vee nose cargo trailer camper conversion... viewtopic.php?f=42&t=58336

We have a small off grid cabin we built ourselves in the NM mountains; small PV solar system; 624 watts PV, Outback CC & inverter/charger ... http://countryplans.com/smf/index.php?topic=2335.0
User avatar
MtnDon
1000 Club
1000 Club
 
Posts: 1939
Images: 6
Joined: Sun Aug 19, 2012 10:57 pm
Location: New Mexico
Top

Re: FAQ:Solar Panel without the Technical Stuff

Postby Bill n Robi » Sun Mar 15, 2015 6:09 pm

They were promoting it to 'save your investment", I don't think I bookmarked that particular but I probably can find it again.

My TD is not metal covered but I figure if there is that much storm activity I don't want to be parked under a tree or be an attractor out in the open. Pack it up and move.

Bil
2015 T@G Max
2015 Toyota Tacoma TRD Sport 4 Door Short Bed
User avatar
Bill n Robi
Teardrop Master
 
Posts: 240
Joined: Mon Dec 01, 2014 4:32 pm
Location: San Diego, Ca
Top

Re: Re:

Postby bdosborn » Sun Mar 15, 2015 7:52 pm

Kaz wrote:This is a good deal too. !00watt panel on a good day will get you a good recharge.You want to look for an MPPT type solar controller.

http://www.ebay.com/itm/100-Watt-12V-Mo ... 418019d07c



The panel includes a controller, which BTW, is a positively grounded.

Please Note: This is a Positive Ground Charge Controller. If grounding is necessary, it must be completed on the positive line. If the controller is to be used on a vehicle which has battery negative on the chassis, loads connected to the controller must not have an electrical connection to the vehicle body.


Pretty useless for a teardrop and TV that is negatively grounded. It's typical to throw in a low quality or oddball controller on these ebay deals. I'd buy a panel only and then invest in a quality controller. As Don said, its not worth the extra expense for MPPT on a single panel like this, especially since the panel voltage is appropriate for a 12V PWM controller. The PWM controller will be at least a hundred dollars cheaper than MPPT and will only be around 10% less efficient.

Bruce
2009 6.5'X11' TTT - Boxcar
Image
Boxcar Build
User avatar
bdosborn
Donating Member
 
Posts: 4214
Images: 450
Joined: Wed May 05, 2004 11:10 pm
Location: CO, Littleton
Top

Re: FAQ:Solar Panel without the Technical Stuff

Postby Esteban » Tue Mar 17, 2015 1:50 pm

If you search Amazon.com for a mppt controller you'll find many choices available. However some low cost ones may not really be mppt controllers.

One mppt controller with good reviews is the MPPT Tracer1210RN Solar Charge Controller Regulator 12/24V INPUT 10A that is currently priced at $71.00.

Specification:

* Model No: Tracer-1210RN
* Nominal System Voltage: 12VDC | 24VDC Auto work
* Rated Battery Current: 10A
* Maximum Battery Voltage: 32V
* Max. Solar Input Voltage: 100VDC
* Max. PV input power: 12V/ 130W 24V /260W
* Self-consumption: <10mA(24V)
* Charge Circuit Voltage Drop: <=0.26V
* Discharge Circuit Voltage Drop: <=0.15V
* Communication: TTL232 / 8pin RJ45

It is rated for a maximum PV input up to 130 watts at 12 volts. More than enough capacity for a single 100 watt 12 volt solar panel. It might be worth it to pay a little more for a mppt controller than a pwm controller to more efficiently harvest power from your solar panel when roof top real estate on a teardrop is a limiting you to just one solar panel.
Steve - SLO, CA
Esteban
Donating Member
 
Posts: 1538
Images: 15
Joined: Fri Jul 28, 2006 4:39 pm
Location: California, San Luis Obispo
Top

Re: FAQ:Solar Panel without the Technical Stuff

Postby bdosborn » Tue Mar 17, 2015 10:12 pm

Esteban wrote:If you search Amazon.com for a mppt controller you'll find many choices available. However some low cost ones may not really be mppt controllers.


Head over at the NAWS forum and do some research on cheap MPPT controllers. I haven't looked at controllers in awhile but when I did I found that 99% of cheap units they tested were junk. Post a link if you find something they recommend as I'd be interested in it.

http://forum.solar-electric.com/forum

Esteban wrote: It might be worth it to pay a little more for a mppt controller than a pwm controller to more efficiently harvest power from your solar panel when roof top real estate on a teardrop is a limiting you to just one solar panel.


The math on MPPT is pretty lopsided for a little panel. I can buy a good PWM controller for $40. A cheap MPPT controller (that actually WORKS) will be at least $200, probably more. It will boost your output by 15% tops and you'll only get that when your battery is deeply discharged and it's a cool day. Most of the time it's around 10%. That means you just paid $160 for 15 extra watts out of a 100 watt panel. That's almost $11/watt when you can find panels for $1.50/watt. I'd rather spend that money on an additional ground mounted panel and a controller sized for two panels. My portable panel always outperforms my roof mounted anyways as I can't help but point it at the sun whenever I walk by. That would be MPTB technology (Maximum Power Tracking by Bruce) :lol:

Bruce
2009 6.5'X11' TTT - Boxcar
Image
Boxcar Build
User avatar
bdosborn
Donating Member
 
Posts: 4214
Images: 450
Joined: Wed May 05, 2004 11:10 pm
Location: CO, Littleton
Top

PreviousNext

Return to Electrical Secrets

Who is online

Users browsing this forum: No registered users and 5 guests