Solar Panel Open Discussion/Debate/Review

[Lanlubber In Remembrance]

I don't run an inverter at home. Everything is 12 volt.

GHB 20A 12V 24V Solar Charge Controller Auto Switch LCD Intelligent Panel Battery Regulator Charge Controller . It was about $30.00. I haven't had any issues.

This one is in my trailer, Valterra Power Us, Llc GP-PWM-10-USB Solar Controller 10A Digital

There are plenty of good ones. I own 3.. Don't get analysis paralysis.

The Valterra Power is only 10a. I thought you were recommending a 30a controller if I have more than 100w solar panels. ???

 

[Lanlubber In Remembrance]

Me too LOL! Again, I don't need a charge controller yet but will grab one if a decent one goes on sale for Prime day tomorrow, didn't find anything today!

I think every solar panel needs a charge controller to protect the battery from overcharge. It's the inverter that isn't necessary as long as you don't need 110v service. If I'm wrong some please straighten me out.
Lanlubber

 

[OtherOrb]

I think every solar panel needs a charge controller to protect the battery from overcharge. It's the inverter that isn't necessary as long as you don't need 110v service. If I'm wrong some please straighten me out.
Lanlubber

Every Array needs a controller that can accommodate that array's output. If you have three 12V, 100W panels that each put out 5.5 Watts, and your array has the panels in parallel (12 Volts, 16.5 Amps), you need a controller that can handle at least 16.5 Amps.

If you wire your panels in series (36 volts, 5.5 Amps), then your controller needs to handle a minimum of 5.5 Amps.

Or you can wire a controller to each panel and then connect those controller in series or in parallel.

 

[Lanlubber In Remembrance]

Every Array needs a controller that can accommodate that array's output. If you have three 12V, 100W panels that each put out 5.5 Watts, and your array has the panels in parallel (12 Volts, 16.5 Amps), you need a controller that can handle at least 16.5 Amps.

If you wire your panels in series (36 volts, 5.5 Amps), then your controller needs to handle a minimum of 5.5 Amps.

Or you can wire a controller to each panel and then connect those controller in series or in parallel.

Well yes, I have four 25w s. panels that forms an array of 100watts. I have one charge controller that is connected to each 25w solar cell panel. My assumption is: I must have a charge controller between the s. panel array and the battery. My kit came with the c. controller attached to the back side of one of my 25w panels. All the panels are plugged into the c. controller. Once connected the lead wires (positive and negative) from the controller goes to the battery from the c. controller. It will deliver 100 + - watts of 12v power @ somewhere around 6a to the battery. If I want 110v power then I must place an inverter between the c.controller and the battery. In summerizing this I need a controller that is in excess of 6a, mine is 10a so I am good. Now if I add 2 more 100w s. panels, about 12a added to the original 6a, it adds up to 18a. Knowing this I need a 20 a c.controller to handle the 18a going to the battery. To be safe and prudent I would buy a 30a c. controller in case I add another 100w panel. Is that a true assumption or not ?
Lanlubber

 

[Viking1204]

I think every solar panel needs a charge controller to protect the battery from overcharge. It's the inverter that isn't necessary as long as you don't need 110v service. If I'm wrong some please straighten me out.
Lanlubber

Remember, my Flexopower has a Lithium battery with built in MPPT Charge Controller. I'm just watching Amazon's Prime Day deals in case I want to grab a controller for my future plans.

 

[Viking1204]

Alright, if anyone has questions about Charge Controllers Will does a pretty good job of comparing them and explaining things!

 

[Road]

Well yes, I have four 25w s. panels that forms an array of 100watts. I have one charge controller that is connected to each 25w solar cell panel. My assumption is: I must have a charge controller between the s. panel array and the battery. My kit came with the c. controller attached to the back side of one of my 25w panels. All the panels are plugged into the c. controller. Once connected the lead wires (positive and negative) from the controller goes to the battery from the c. controller. It will deliver 100 + - watts of 12v power @ somewhere around 6a to the battery. If I want 110v power then I must place an inverter between the c.controller and the battery. In summerizing this I need a controller that is in excess of 6a, mine is 10a so I am good. Now if I add 2 more 100w s. panels, about 12a added to the original 6a, it adds up to 18a. Knowing this I need a 20 a c.controller to handle the 18a going to the battery. To be safe and prudent I would buy a 30a c. controller in case I add another 100w panel. Is that a true assumption or not ?
Lanlubber

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I think your assumption is correct on the charge controller, yes, IF your added new panels top output is 6amp. Not all panels are equal in output. My 120w folding panel, for example, can put out 7amps regularly and will even exceed that at times. Generally speaking, less expensive panels with less efficient cells produce less amps. See below for a link to a chart comparing solar panel efficiency for 2019.

If you get more panels, bypass the controller on your four panel setup and place your new, better, charge controller close to the battery. Closer to the battery is better.

Better charge controllers will provide more info, too, as to amp input, Amp hours (Ah) stored in session, voltage, and are much better at sensing battery condition, and can be set for battery type (AGM, etc). They will charge in stages, ending in a float charge to keep a battery topped off, and will equalize all batteries in a system to ensure they are equally charged. See the posts in the thread Solar Power 101 here on OB for more info on charge controllers, set ups, and links to items and products mentioned in the post.

There is also a good article at AM Solar with Frequent Questions: Charge Controllers. Though the article is from three years ago, it has some great info on use of multiple charge controllers and other points.

BUT, YOUR INVERTER, @Lanlubber , should you choose to install one, should not go between the charge controller and battery if you want consistent power and longer inverter life. It should be hooked to the battery (or battery bank), just as it would be if there were no solar system attached. Hooking directly to the charge controller, though technically can be done, would lead to potential intermittent power to the inverter as the sun appears/disappears.

Choosing panels: Some panels produce far less amps, or none, if one of the cells in a panel is shaded. Better panels will still produce power if one of the cells in the panel is shaded. It really does pay to research a new panel before purchase, and see if you can determine where they get their cells. Some vendors will shop around. The cells they used last year may not be the cells they use this year. Currently, solar panels from Sunpower Maxeon are the most efficient, as rated independently. Here's a great page with info on solar cell efficiency with a chart comparing, if you scroll down: Solar Panel Efficiency.

Good luck with your set up.

.

 

[Viking1204]

Anyone with the cash and want a good Lithium 100ah battery should check out Amazon's current deal on the Renogy battery! Price is $688.49 when you go to Prime Deals page and search for 100ah Lithium Battery, not sure why link won't stay at that price or take you to the same place.

 

[smritte]

Nice chart. To make it better, I have a Sun Power panel. Buying that was pure coincidence. I'm only a little surprised about how inefficient some of the panels are. When I first started learning solar, most of the cheap panels were under 12% efficient and some being closer to 10%. The better being 14%. The cost was very high. Then several years ago, solar evolved and it evolved again not long ago. Panels are better and less cost.
I'm hoping in my lifetime, I see panels pulling close to 100% available energy from the sun. Were getting there slowly.

 

[Road]

Nice chart. To make it better, I have a Sun Power panel. Buying that was pure coincidence. I'm only a little surprised about how inefficient some of the panels are. When I first started learning solar, most of the cheap panels were under 12% efficient and some being closer to 10%. The better being 14%. The cost was very high. Then several years ago, solar evolved and it evolved again not long ago. Panels are better and less cost.
I'm hoping in my lifetime, I see panels pulling close to 100% available energy from the sun. Were getting there slowly.

.

Yep, greater efficiency and prices coming down. I have SunPower Maxeon cells in my panels, too, and may get two 100w panels of the same if they become available again, and make my own portable 200w setup for deep cycles in the van. Then I'll have redundant gear and will be able to be away from basecamp for long as I want in the van and still be able to keep my food cold, charge my bike and camera gear and assorted batteries and lights and power packs, and run the vent fan just about anywhere I go.

.

 

[bmwguru]

Anyone with the cash and want a good Lithium 100ah battery should check out Amazon's current deal on the Renogy battery! Price is $688.49 when you go to Prime Deals page and search for 100ah Lithium Battery, not sure why link won't stay at that price or take you to the same place.

That deal might be expired. They are currently on sale direct from Renogy for $720 Renogy Lithium-Iron Phosphate Battery 12 Volt 100Ah

 

[Lanlubber In Remembrance]

Remember, my Flexopower has a Lithium battery with built in MPPT Charge Controller. I'm just watching Amazon's Prime Day deals in case I want to grab a controller for my future plans.

Oh, okay, makes perfect sense. There was a good posting on solar today and I was glad to find out I was right about the storage of energy being more important that the number of watts the solar will produce. So it's onward and upward for me on my solar. I ordered my 1100 - 2200 inverter yesterday, picked up my second battery from wally world, received my duel batter cables in the mail, receiver my 5a solar battery tender for my other vehicles that don't get driven enough, will receive tomorrow my front winch plate for my planned front bumper build, going to Albuquerque on the 5th to pick up my custom safari roof rack, received my 1" wheel spacers for a better stance on the LRD2. I probably missed a few things but sitting at home all day staying off my feet allows to just spend and spend on the internet.
Lanlubber

 

[4wheelspulling]

One thing not mentioned yet is having the right “type”of charge controller. With some solar panels, you have to use a MPPT charge controller, to get full efficiency ! My home is setup off-grid. I have been using my current setup for 7 years, still putting out the same amps of power as when new. Also, I know everyone thinks they need a sine wave inverter, when buying one, but in truth, most people would be served just as well with a Modified wave inverter. I run everything, iPads, cell phones, radios, TVs and more and never have had a problem, on a modified wave inverter. I take that back, my wife had a heated hair straightener, that did not work. But that is it! I set my brother up with a solar system 20 years ago, he is still using everything, but has replaced the batteries of course!

One problem I see over and over are people using the wrong crimping tools when making connectors. The crimpers you get at your local automotive parts store are junk. Most don’t understand when you should use solder and when you should not! It would amaze people how much power is lost by poor crimping and wrong technique. Do any of you check your connections with a multimeter? You should be doing so. Vance.

 

[Viking1204]

One thing not mentioned yet is having the right “type”of charge controller. With some solar panels, you have to use a MPPT charge controller, to get full efficiency ! My home is setup off-grid. I have been using my current setup for 7 years, still putting out the same amps of power as when new. Also, I know everyone thinks they need a sine wave inverter, when buying one, but in truth, most people would be served just as well with a Modified wave inverter. I run everything, iPads, cell phones, radios, TVs and more and never have had a problem, on a modified wave inverter. I take that back, my wife had a heated hair straightener, that did not work. But that is it! I set my brother up with a solar system 20 years ago, he is still using everything, but has replaced the batteries of course!

One problem I see over and over are people using the wrong crimping tools when making connectors. The crimpers you get at your local automotive parts store are junk. Most don’t understand when you should use solder and when you should not! It would amaze people how much power is lost by poor crimping and wrong technique. Do any of you check your connections with a multimeter? You should be doing so. Vance.

So those of you off grid with a true solar system what kind/brand of batteries do you recommend? My goal is to build an off grid house on some land before I retire so trying to learn as much as I can now. Been watching a show called Building Off Grid that I've been recording and enjoying those shows but they don't ever go into what kind of solar panels or batteries they're using. Seen some pretty amazing stuff, one guy used mushrooms to insulate a cottage he built and a couple of them now have used straw bales for their walls, apparently they have an R35 insulation value. Seems like a lot of work! I like the guys that buy a bigger piece of wooded property and bring a portable sawmill on site and cut their own trees and mill the wood and build their house from the wood on their property!

 

[Lanlubber In Remembrance]

So those of you off grid with a true solar system what kind/brand of batteries do you recommend? My goal is to build an off grid house on some land before I retire so trying to learn as much as I can now. Been watching a show called Building Off Grid that I've been recording and enjoying those shows but they don't ever go into what kind of solar panels or batteries they're using. Seen some pretty amazing stuff, one guy used mushrooms to insulate a cottage he built and a couple of them now have used straw bales for their walls, apparently they have an R35 insulation value. Seems like a lot of work! I like the guys that buy a bigger piece of wooded property and bring a portable sawmill on site and cut their own trees and mill the wood and build their house from the wood on their property!

Scott, just for now go with what works for your camping. By the time you retire everything will have changed in the solar industry. That's why I am not interested in buying the best, the best is yet to come. Buy cheap and learn, anything you buy now will be obsolete before to long in that industry. Being a building designer I know about that sort of stuff. Straw bales are a tough build (too complicated) and can only be built with dry conditions. Concrete filled 12" foam block is the best and easiest method of construction next to stick framing for a DYI build.. You'll need to know exactly where you are going to live to decide on your construction materials. Log houses are great in mild to humid areas, good in dry areas too if you want a lot of upkeep. (Lumber shrinkage) Good to plan and dream but you can only go so far in planning without more knowledge of where you will live.
Lanlubber

 

[Viking1204]

Scott, just for now go with what works for your camping. By the time you retire everything will have changed in the solar industry. That's why I am not interested in buying the best, the best is yet to come. Buy cheap and learn, anything you buy now will be obsolete before to long in that industry. Being a building designer I know about that sort of stuff. Straw bales are a tough build (too complicated) and can only be built with dry conditions. Concrete filled 12" foam block is the best and easiest method of construction next to stick framing for a DYI build.. You'll need to know exactly where you are going to live to decide on your construction materials. Log houses are great in mild to humid areas, good in dry areas too if you want a lot of upkeep. (Lumber shrinkage) Good to plan and dream but you can only go so far in planning without more knowledge of where you will live.
Lanlubber

No worries, that's what I plan to do. Right now I'm just learning and asking questions to help me learn. My youngest Seth graduates High School in 7 years, my goal by then is to just have the property. I know what you mean, I imagine Solar by then to be a lot more efficient and come down in price a lot. It seems like right now Solar is starting to become more mainstream and something more and more people are getting interested in it. I pretty much have most of what I want for camping and hunting this fall except for the RTT, have to save for the next couple months and hopefully get one when REI has their fall member sale or sooner if I find a good deal on one I like.

 

[Lanlubber In Remembrance]

No worries, that's what I plan to do. Right now I'm just learning and asking questions to help me learn. My youngest Seth graduates High School in 7 years, my goal by then is to just have the property. I know what you mean, I imagine Solar by then to be a lot more efficient and come down in price a lot. It seems like right now Solar is starting to become more mainstream and something more and more people are getting interested in it. I pretty much have most of what I want for camping and hunting this fall except for the RTT, have to save for the next couple months and hopefully get one when REI has their fall member sale or sooner if I find a good deal on one I like.

I have to agree with an article posted recently about the need for solar if your only out there for a few days (up to three). Solar is for when you are not driving enough to keep your batteries charged from your auto. That is why I am using two batteries for my camping, not connected to my car battery. I plan camping for up to 14 days without driving my rig. I will be able to go six days without a charge with two batteries. A solar will benefit me to keep my batteries charged instead of depleting. My 100w solar will do that as my only major use of electricity is for the refer and a few hours of internet when it's available.
Lanlubber

 

[Road]

So those of you off grid with a true solar system what kind/brand of batteries do you recommend? My goal is to build an off grid house on some land before I retire so trying to learn as much as I can now.

.

Not sure what you mean by a 'true' solar system. What would make it an untrue system?

I have a solar system with which I go off grid for most of every year.

Last adventure was eight months long in a variety of locales and situations, from open desert to swamps and bayous to dense woodlands. I would not hesitate to use the same exact system if I was living off-grid in one place, homestead-style, though may increase my storage capacity. I'm planning on doing just that with redundant setups in van and trailer that can work together or apart.

I use two Odyssey AGM Deep Cycle, Performance series. They are the same as the Odyssey Extreme series without the CCA (cold cranking amp) needed for starting engines. Because I already have twin starting batteries for my diesel van with high CCA, I don't need that feature in my deep cycle storage batteries.

Having gone off-grid for seventy-five percent of the last two years--meaning living without using conventional 110 from electric companies for any of my power needs--I've learned what I need and don't need. I believe most people use far more than they truly need because it's right there in the wall, convenient to use and easy to waste. Most folks do not think about where the power comes from or at what cost.

When you live off-grid and depend on yourself to generate your own power, you're much more aware of your needs, how to obtain it, how to store it, and how to use it wisely. With my small system, I regularly keep my food cold, all my photography, bike, computer and other device, flashlight, and all other batteries charged and ready. I also run my water pump, air compressor, on-board LED lights, and supply power to a 1000W pure sine 110 inverter if I have something that needs 110v, not 12v.

My panels get moved around when I'm in intermittent sun, angled for efficiency throughout the day. When in 24hr open sun or when driving, the folding panel is stored on the rooftop ten shell, gathering energy in a flat position.

I also have a small Honda Generator for back up, which I have converted to run on propane or gasoline. I had it for over a year before I ever used it, and then for helping power a small community festival at which my trailer was HQ.

I've experimented endlessly with my power needs and supply capacity. This is the same exact system I'd use in an off-grid homestead, just mobile. In fact, my intention when choosing a trailer and designing my setup was to use my trailer and it's power supply as foundation for any more permanent off-grid homestead, while retaining the ability to move if needed.



Power Center with two Odyssey Performance Deep Cycles, each 50Ah and on their own shelf, Blue Sea 6 Circuit fuse box (on the right wall) to fuse and distribute power from the batteries, and NOCO Genius 2 Battery Minder (on the near wall), which allows me to plug into 110 if available, to also charge and equalize the batteries. I've used the NOCO mostly to plug into my dual fuel Honda Generator in times of extended inclement weather or when deep into heavy forest cover.


Desert Borderlands photography bunker, in which I stayed for over a month, providing all my own power for fridge, camera batteries, ebike, lighting, etc.



New England woods camping.

 

[Road]

That's why I am not interested in buying the best, the best is yet to come. Buy cheap and learn, anything you buy now will be obsolete before to long in that industry.

.

I can't always agree with buying cheap as being the best way to learn, @Lanlubber. I've bought cheap and I've bought the best I could afford. Too many times having the cheapest of something can be frustrating and doesn't help me learn well. Not saying you, or anyone else, has to be like me, but I've found that getting the best I can afford is less expensive in the long run and lasts a lot longer, creates a far greater understanding of what I'd hoped to learn, and is way less exasperating in trying to understand how something works.

There may be something better to come in future, but having the best I can afford now has always been the wisest choice for me.

.

 

[Road]

I have to agree with an article posted recently about the need for solar if your only out there for a few days (up to three). Solar is for when you are not driving enough to keep your batteries charged from your auto. That is why I am using two batteries for my camping, not connected to my car battery. I plan camping for up to 14 days without driving my rig. I will be able to go six days without a charge with two batteries. A solar will benefit me to keep my batteries charged instead of depleting. My 100w solar will do that as my only major use of electricity is for the refer and a few hours of internet when it's available.
Lanlubber

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The best independent system uses a variety of power input and is flexible depending on need and situation. I've found over the years that solar is my primary input for power, as I tend to basecamp for weeks at a time. I depend on both solar and my van's alternator when underway to charge my deep cycles. I rarely use my generator to provide power to top off my deep cycles or for direct power, but it's there if the need arises, like an insurance policy. I even more rarely use shore power, such as 110 hookups at house or campground and don't even bother making it a consideration when I stop anywhere.

The point is, there are no absolute rules about how many days for this or that or if it's more than three you have to do this. Create a flexible, multi-sourced system you can adapt to the situation.

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