Best products from r/solar

We found 71 comments on r/solar discussing the most recommended products. We ran sentiment analysis on each of these comments to determine how redditors feel about different products. We found 218 products and ranked them based on the amount of positive reactions they received. Here are the top 20.

10. CHAFON 40W Portable Solar Charger with Foldable Panel,18V DC 5521 Output for Portable Power Station Solar Generator,Laptop Tablet,5V/2A USB Port Compatible with iPhone Xs Max/XR/X/8/iPad/Galaxy s9

  • HIGH PERFORMANCE SOLAR PANEL: With a high conversion efficiency up to 22%, Chafon 40W mono-crystalline solar charger can absorb strong sunlight and charge your devices, energy saving and eco-friendly. With 2 adjustable kickstands, it can be placed to catch the sunlight at an appropriate angle, and be hanged at your tent or rv via the 2 holes as well.
  • WIDE COMPATIBILITY: Equipped with 1*DC Output, 1*USB QC3.0, and 10-in-1 connector kit, this flexible folding solar panel has a wide compatibility to power your phones, power banks, tablets, laptops, GPS, digital cameras and most portable power stations and solar generators.
  • FOLDABLE, PORTABLE & LIGHTWEIGHT: With a lightweight of 4.85lb and a solid handle, the foldable solar panel can be folded into a handbag with a portable size of 13.4 x 9.8 x 2inches, convenient to be carried wherever you go. The solar panel is IP65 water-resistant to bad weather conditions.
  • HIGH DURABILITY AND WATERPROOF: ApowKing portable solar panel is made of PET laminate, sturdy and durable. The main-board is designed with IPX4 waterproof materials, suitable for some bad weather conditions, suitable for outdoor life and even unexpected power outages. NOTE: The junction box is not waterproof and please keep it dry.
  • WHAT YOU WILL GET: 1* 40W Solar Panel, 1*5ft DC charging cable, 1*10-in-1 connector kit, 1*user manual, 7*24 friendly customer service. This solar panel does not store a charge, and the output may be less than 40 watts at different angles or in cloudy weather. Any problem, please feel free to contact us.
CHAFON 40W Portable Solar Charger with Foldable Panel,18V DC 5521 Output for Portable Power Station Solar Generator,Laptop Tablet,5V/2A USB Port Compatible with iPhone Xs Max/XR/X/8/iPad/Galaxy s9
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19. 20A Solar Charge Controller Solar Panel Battery Intelligent Regulator with Dual USB Port 12V/24V PWM Auto Paremeter Adjustable LCD Display

  • ☀☀☀20A Solar Charge controller : Binen solar charger controller are UL 1741 certified,the solar charger controller compatibility with 12V 24V system. Discharge Current: 10A,build-in industrial micro controller, automatically manage the working of solar panel and battery in solar system. Dual USB output 5V/2.5A (max), to support mobile phone chargeing.
  • ☀☀☀Multiple Protection Functions: Binen solar controller has short-circuit protection, open-circuit protection,reverse protection, over-load protection. Fully 3-stage PWM charge management, improve system efficiency and prolong the life span of the battery.
  • ☀☀☀Battery Type: The charge regulator is only suitable for lead-acid batteries: OPEN, AGM, GEL, it is not suited for nickel hydride, lithium, Liions, or other batteries. For protecting the lifespan of your battery, once the voltage of the battery drop below 8V, the solar controller will turn off automatically.
  • ☀☀☀LCD Display: Comes with a display that can clearly indicate the status and data, it can be conveniently switched modes and parameter configuration, suitable for home, industrial, commercial etc.
  • ☀☀☀Easy to Install and Operate: The charge controller should connect the battery first, then the solar panel, and finally the load! The disassembly sequence is contrary to the wiring order.Dual mosfet Reverse current protection, low heat production. ( Note: The charge controller will heat up when it is running. Please be careful to install the charger controller on a flat, well-ventilated place)
20A Solar Charge Controller Solar Panel Battery Intelligent Regulator with Dual USB Port 12V/24V PWM Auto Paremeter Adjustable LCD Display
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Top comments mentioning products on r/solar:

u/rosinall · 5 pointsr/solar

Hi, this is simple if your expectations are in line, and unworkable if not.

If you want to run devices that heat or cool with electricity, such as coffeemakers, hotplates, A/C, toasters, hair dryers, etc., you will not make your numbers or anywhere near them. Give that all up. There is a reason whole-house systems cost $30-40k, it is heating and cooling.

Now for the awesome: IT WORKS. I ran 30 feet of LEDs, a laptop, a small but nice stereo, a PoE wireless antenna, a wireless hub, iPhones and iPods, 18v DeWalt battery packs, a fan — plus whatever I am forgetting — off of 2 x 100W solar panels and 2 x 100Ah marine cells for ten weeks. I went dry twice, but with a fully charged laptop, stereo and phone.

First you must go ahead and do all the math of your usage, because we are are still at the stage where we must all do all the math, and math is good, but when you are doing all the math to the third significant digit, and looking up the model of that rechargeable flashlight you like for its charging amperage requirements, maybe say fuck it and start with half that; one beefy panel, one solid battery. You could easily add another panel and battery later.

As to wiring, your charge controller will have connections that include a legend where to hook up your batteries, panels and inverter, so easy peasy there. See the link below for an example. I recommend spending the extra on an MPPT controller, which converts some of your extra juice (the 12V panel below can run almost 19V) that normally is dumped when charging into increased amperage of the charging current. Do the math of your expected load, it's possible you will want a 20A. If it doesn't include fusing directions, go online and find a schematic of where to add inline fuses that, if that are not included, you will get at the auto parts store.

YOU WILL WANT TO DO THE MATH on wire sizes. There are calculators online. For your small setup, the important run is going to be between the battery and the charge controller. This is where the fires start. If you think you will EVER add another battery dig deep and wire for it.

For inverters, I feel better about everything by getting a well-respected pure sinewave unit. I run a Xantrex 600W in my 4Runner and a Cotec 350W for the solar, and they feel bulletproof. You could save a ton, and maybe in this case you should, by getting a cheap modified sinewave one and seeing if it meets your needs. Either way they will have outlets on them, so you don't need to wire it further.

Also, no SLA batteries inside the vehicle unless properly secured, sealed inside, and vented outside.

I also recommend the /r/vandwellers subreddit, it is excellent. This comes up there a lot, although this is the better place for the question.

Solar panel:

Charge controller (10A likely okay, do your math, I got the 20 amp)


u/brianwski · 2 pointsr/solar

I spent a week in an RV “off grid” with the following solar setup to charge electronics and power electric blankets at night for warmth while sleeping:

Battery with three prong outlet plus USB charging ports:

NOTE: I paid $350 for that battery, but it looks like it is no longer sold. This one looks even better for $175:

Solar panel to recharge battery:

I paid $120 for the solar panel.

I don’t know if it is the cheapest solution, but it worked wonderfully and didn’t require ANY complicated integration, just plug together and done! If the solar panels did not keep up the charge, my backup plan was to run the generator built into the RV to charge up this battery, but it was never necessary!

This particular battery pack comes with an LED light, kind of a flashlight with a gigantic battery. I originally thought that was silly, but I ended up liking the feature for off grid living -> if you get up in the night and need a bit of light, toss the light switch and you can see what you are doing.

After my “off grid” camping trip, I turned the setup into a UPS for my computer, and it works great for that also. Plug the battery into a wall outlet, and computer into the battery, and when the power goes out, the computer still runs off of the battery for a few hours. I even used the solar panels to charge it back up during a 20 hour residential power outage a couple of weeks ago.

What I learned: normal computer UPS (Uninterruptable Power Supply) batteries are lead based which is heavy and clunky, and this battery pack is lithium ion so smaller and lighter. But lithium ion costs more for the weight savings.

u/graffix01 · 2 pointsr/solar

This is basically what I have. I bought a different battery and inverter because I have an account at batteries Plus but this is a widely accepted quality battery and a decent inverter. I would recommend buying at least the battery local as shipping them is expensive.

NOTE I did not include fuses/breakers in this list but you definitely should build these into your design.

Depending on what you really want to power this may be way more than you need. You really should start by figuring out the load you want to power and then design your system around that number. This is a great little tool for figuring out how much power the devices you want to power will use and it's certainly cheaper than buying too much system and finding out you could have done what you wanted with half as much as you bought.

I'm certainly not an expert at solar but am learning so feel free to PM any other questions.

u/joergonix · 1 pointr/solar

Thank you so much! That is incredibly helpful information.

Hypothetically if I were planning to spend about $700 on the solar setup and batteries do you think I would be smarter to save a bit of money on the controller by going PWM rather and MPPT and put it into an extra panel? I could do 3 panels, and 2 of these: AGM 12v 100ah batteries. Price would be similar to the golf cart batteries. Would this setup be an improvement?

Also found a good deal on a DC fridge that consumes about 4.2amps which at 12v would be about 50watts and should theoretically be awesome for my setup right?

Do you think

u/traveler19395 · 3 pointsr/solar

You need to stay within the amperage limitations of your wiring and charge controller.

For instance, this is a good charge controller that can do 75v and 15 amps, so in theory you would think it could do 1125 watts. But that's not the way it works. You need to keep peak voltage and amperage under 100/15, and load voltage and amperage will be a good bit less.

You could run three 300w panels like this in parallel with a charge controller that can handle 40v 30 amps, or you could run the same panels in series with a charge controller that can handle 120v 10 amps. The wiring needs to handle the amperage, so much smaller wiring would be needed for the latter.

If you did more, smaller panels, like six 150w panels, you could do a series/parallel combination for something like 80v at 15-20 amps. That would go very nicely with this charge controller.

And then there's the decision of how likely you are to want to expand the system and if you should buy equipment that can handle more panels.

Create a short list of your preferred charge controllers and their capacities, then start shopping for panels and do the quick math. If the panels were the same dollar-per-watt I would probably do six 150w in series/parallel with the controller I mentioned above. If you think it's likely you may expand capacity, I would go with three 300w panels in parallel with this controller, then you could add 6 more of the same (2700w total) in series/parallel without changing your charge controller or wiring.

u/davy_crockett · 6 pointsr/solar

Watts are a measure of power

Watt-hours are a measure of energy


Add "kilo" to the front of each unit and it gets multiplied by 1000.


Power is instantaneous and energy is power over a period of time. Think of them like speed and distance. Just like a faster car will go farther in the same amount of time, a solar panel with a higher kw rating will generate more energy in the same time than a lower kw panel (assuming sunlight conditions and orientation are the same).


When a solar panel is rated for, say, 100 watts, that means that under certain laboratory conditions (a certain amount and intensity of sunlight, a certain temperature of the solar cells), a brand-new panel will produce 100 watts of instantaneous power. However, in the real world, the amount of sunlight varies, the temperature varies, and that same panel will often produce less than 100w or sometimes more than 100w.


If you want to get a sense of how much a watt and watt-hour really is, then I recommend getting a Kill A Watt meter. It's something that you put between an appliance and a wall outlet and will measure how many watts and watt-hours that appliance uses for however long you have it connected. You can also check the electricity bill for your house, which will show how much energy (measured in kilowatt-hours) your house uses in different months of the year.

u/chopchopped · 1 pointr/solar

This has been fun but I have some things to do. Here's a good book to read

Solar Hydrogen: Fuel of the Future

Renewable hydrogen produced using solar energy to split water is the energy fuel of the future. Accelerated innovation in both major domains of solar energy (photovoltaics and concentrated solar power) has resulted in the rapid fall of the solar electricity price, opening the route to a number of practical applications using solar H2...more

u/gsasquatch · 1 pointr/solar

I want the cheapest, lightest, smallest, best way to get 3 amps at 12 volts 24 hours a day for 7 days straight at 47 degrees latitude in the summer in the US. How would I do it?

My thinking is 100watt panel at $150 I kind of like the flexible for my application, and lighter is better here:

This could work, but the metal and glass and weight will be harder to mount:

A second panel, esp. flexible is not out of the question.

A mppt controller at $100 I'd like the controller to have the possiblity of a second panel.

Can I get away with one of these:

Or is something like this better:

How close can you run the controller to the limit, is a 20amp controller good for 200watts of panels, or is it better to not be so close and go to 30amp?

A 4x10 amp hour 12v in parallel, LiFeP04 bank at $500 (battery might be a bit small, but 3 amp constant might be a bit exaggerated and a dark period might be ok) 17lbs

SLA could work probably x2 Can you run the SLA as far down as a LiFEPO4? 3x the weight, but 1/3 the cost. How does the life compare?

Am I thinking wrong, or missing something significant other than wires and connectors?

Are their controller considerations if looking at LiFEPO4 vs. SLA?

u/geman220 · 1 pointr/solar

I did read through that website. However, the battery bank does have pass through. I tested first by connecting the battery bank to a normal wall outlet to charge, and connected my controller / servo. It was able to charge while also running the controller. I was using this solar panel.

As far as solar here is what I've found doing tests:

  1. Controller + Servo + Battery connected to wall outlet. I was able to run "forever". I also drained the battery a bit and re-connected it to the wall and it charged back to full while running.
  2. Controller + Servo + Battery (Full Charged) + Solar. I was able to run for ~50 hours. I didn't have an exact time that it died but it did pass 48 hours before dying.
  3. Controller + Servo + Battery (Full Charged). I was able to run for around 24-ish hours. Again I didn't have an exact time.

    My solar panel is probably only getting 4 hours of direct sunlight, so my assumption is I'm getting 4 hours of "free energy" with a bit of charge.

    Is there a reason why 6W Voltaic panels are so much more expensive? Thanks for the help.

    EDIT: Just realized the link you sent for Voltaic is in New Zealand, that explains the cost. Do you think I would need a 6W or a 9W?

    Here are my findings for power consumption, keeping in mind 90% of the run time will be idle. When the servo does run it only rotates for about 1 second. So you can estimate 4-5 seconds of servo run time per day.

  • Servo draws 0.00A connected but not rotating
  • Servo draws .5A max (sometimes less) when turning only
  • Controller draws .13A max observed (usually .09A) this is a constant load
  • Absolute max draw I could find when turning the servo (with controller connected) is .43A rounded up to .5A @ 5V = 2.5W power draw.
  • Idle time with just the controller is .13A max .09A average @ 5V = .65 W higest observed .45 W average

    Let's assume no solar panel to get a baseline. .45W x 24hr = 10.8Wh for 1 day of idle usage. If I assume 4 hours of good direct sunlight I need 10.8Wh / 4h = 2.7W. I also need .45W for the 4 hours to run the device so .45W x 4h = 1.8Wh. Finally add the two for (refill 24 hours of battery)2.7W + (run for 4 hours)1.8W = 4.5W. So essentially I need a panel that will provide a solid 4.5W for 4 hours to fully charge my battery + run the controller. Is this correct?
u/pyromaster114 · 1 pointr/solar

So, you don't want the cheap PWM controllers they sell in those kits. They're inefficient and can't handle nearly the load you're looking for, from the sound of it.

Charge Controllers:

Yep, additional panels will require a much heavier controller. You're looking at a quite sizable system to run an air conditioner.

I'd recommend a Midnite Classic 150 or one of the larger Victron charge controllers.


As far as panels, I'd recommend you look into ordering a pallet or two of utility-scale, 60 cell panels. There's a lot of brands out there, but all perform almost equally. The real decider is price per Watt and warranty coverage, at least for me. I've got a lot of different panel brands, Canadian Solar, Trina Solar, Renogy, some Solar City ones iirc. I don't really have too much brand loyalty here.

Don't buy the 100 Watt panels designed for RV mounting though... they're expensive per Watt. You want to be around ~60-70 cents per Watt or less when buying panels.


Don't buy marine batteries like the one you linked to. You want at the very least, purpose built deep cycle AGM ones like these:

Again, unless I'm misunderstanding what you want to use this system for, a single flooded marine battery is not going to cut it.


The battery you linked to needs at least ~300 Watts to 'normally charge' it, in South Florida on a sunny day. But again, that's with no load on it. It doesn't really make sense to talk about charging a battery without establishing what your loads are first.

u/Watada · 4 pointsr/solar

If you only need power for a day or two you would probably be better off with a USB charger for those batteries and a huge battery bank. Something like this would charge each of your devices up to three times.

Assuming you need to charge each one a full time every day with a solar panel you would need something like this and it would require between 3 hours and 9 hours in direct sunlight to provide enough power. The panel needs a clear day, to be pointing at the sun, and to be kept cool to provide enough power in 3 hours.

u/buddhra · 0 pointsr/solar

Here's another option for a peltier cooler A/C.

250W peltier cooler - $30 -

3 100W 12V solar panels - $415 -

2 heat sinks and fans - $26 -

add some wire and some mounting odds and ends - $100

So for around $500 you mount this little contraption in a window with the cold heat sink on the inside and the hot heat sink on the outside. When the sun starts shining, the panels will start powering the fans and peltier and you can enjoy that sweet solar A/C.

Of course, a peltier is only about 10% efficient, so it's only going to move about 25W or 85 BTU/hr, but it's free energy right!

u/SegFaultX · 1 pointr/solar

I have these they both work great. Eceen works better in low light, while anker works better with bright direct sunlight. I have tested anker to give the output of 1.3A which was the max my phone could take in before in the afternoon. However I've never actually used them much since I bought them more so for emergency since I don't camp or anything.

u/mydarkerside · 1 pointr/solar

You'll want an AGM deep cycle battery, not standard car battery. Doesn't really matter what the terminals are like since you can always buy different terminal types. I bought two of these from Amazon for about $170 each before tax and have been happy with them. I've also looked into used lithium batteries from medical devices, but it gets more complicated because you need a battery management system.

It gets expensive if you build a 400ah system, so I would look more into energy efficient devices or solutions. I did a google search for raising chickens in cold weather and it actually says don't over insulate or heat the coop. You said oneconcern is the water freezing, so maybe just focus on that.

u/mo_jo · 2 pointsr/solar

I've never used them, but Flycrates says they will ship to places that Amazon sellers won't. According to this page, the main problems are extra shipping costs, customs forms, and import duties that have to be paid. Flycrates will supposedly do that for you and let you know what import duties will need to be paid up front.

AllPowers makes a flexible 100w solar panel that sells on Amazon, and there are other companies that also sell flexible panels.

I purchased an AllPowers flexible+foldable 80w solar charger panel and a Suaoki 150Wh Solar Generator (lithium battery+inverter) for camping, and it's worked well. It will run a few lights and power a laptop. I did have to custom-make the connector cable between them to charge the Suaoki, however.

Hope that helps!

u/arrayofeels · 2 pointsr/solar

Well it just seems strange to have way more inverter capacity than generating capacity. So in this case you have a battery that has 900Wh of capacity, so your little 50W panel will take 18h of full sun to charge it (figure you can get 3 or 4 equivalent hours of sunshine a day, so we are talking most of a week) if you don't have any other load connected. Then if you connect your 1kW inverter and use it at full capacity, you'll discharge the thing in less than an hour. In some specific cases this may be desirable, but in general you need at least as much generating capacity as you have loads, or even more, depending on the load profile. But maybe in your case it makes sense just to have the ability to run the odd 110V appliance off your battery every once and a while, while mostly running DC loads like your light and radio

But I think your biggest problem right now is that you are pairing a panel with 18V Vmp with a 6V battery and a 12V inverter. At the least you need to switch to a 12V battery to use that inverter, but even then you will be wasting alot of solar power by forcing the panel to work at 12V (ie you'll only get around 30W out of it), so you would be better off finding a panel intended for use at 12V, like this one

Edit: you may want to look at this exchange from a few days back. /u/MrCloggy was offering some helpful advice to someone looking to set up a system similar to what you want. Actually, now that we've summoned him, perhaps he'll chime in over here.

u/boom_shaka_lakaa · 1 pointr/solar

I think this is a great idea, and as my contribution, I'd like to recommend this awesome textbook:

I normally hate textbooks, but this one is amazing giving real life examples for all concepts discussed. It doesn't assume any prior knowledge and walks you through the basics of electricity before moving into utility scale power systems and how renewable energy sources connect to the utility. As someone in the solar field, if you complete the electricity and solar parts of the book, you're going to way ahead of most people starting out in solar. Seriously check it out!

u/cmonpplrly · 1 pointr/solar

Hopefully this is the right place. I'm working on wiring my camper and have this 225Wh, LiFePO4 battery pack. I would like to pair it with something like this, a preferably flexible 100w panel. The only way to charge the battery pack is via a 15V 4A wall charger. My battery pack is made to charge via solar, albeit with their proprietary panels. I would have contacted the manufacturer about what peripherals I need to get and ask them if/how I could use 3rd party panels, but the company has gone out of business. My question is, can I buy this solar panel, splice a DC charger tip on to it and charge my battery? Or am I missing some critical steps? I believe the battery pack has a built in charge controller, but I'm not sure. Any help would be awesome. Thanks!

u/majjam13 · 1 pointr/solar

your solar charge controller should have a 12v or 24v output. usually the max on the chargers is 120w. each fan needs 15w.. so u could run a few...

but i would think of adding a battery, to help with keeping the voltage constant.

​ this one has a nice diagram

u/communityDOTsolar · 1 pointr/solar

Ah thanks /u/eliborg. If you know anyone who is just getting into solar, I recommend this book which contains good design and work flow process fundamentals to anyone getting into the industry.

u/ButchDeal · 1 pointr/solar

so you have two 15Ah batteries and two 12Ah batteries
Are you sure they don't have a higher voltage charging options.

So you are going to want to charge 4 devices at once at 7amp (2 + 2+ 1.5 + 1.5). you also need a bit over sized as it is going to take some time so you need to be able to accept light longer (more area).

I have a similar set up for my camping and you get this:
now that has only ONE USB port But you can easily make another with :


NOTE that the USB car charger needs to be able to go up to 24V on the input side as the Solar array will put out 18V
Also the lighter adapter is wired backwards for the array so take it apart and reverse the wires.

With this rig you can charge 5 USB devices, though only at 3.4a total. The solar module only has a max output of 3.4A which is half peak charge rate for all 4 batteries so you could go larger. It will be large enough to charge even if a bit overcast. You can also charge a laptop (though not at the same time as all 5 USB devices).

u/42N71W · 1 pointr/solar

Realistically, the solar panels you can attach to your backpack while hiking through a forest, no.

The easiest solution is to find lower power electronics that will do whatever you need. If you really need a lot of solar power, I'd recommend getting one or more of the biggest folding panel you can, like this, and planning a long siesta in your hiking schedule where you'll find a place to position them optimally for a few hours.

u/nyc4life · 2 pointsr/solar

22w folding panel should be enough for daily phone charging and occasional camera & tablet charging.

#1 seller on amazon:

large battery pack with an lcd display and pass-through charging:

in order to charge your chromebook and a more serious tablet you'll need a bigger solar panel and a bigger battery. /u/dij-8al's solution would be a better fit.

u/CJOttawa · 2 pointsr/solar

Best in class:

Anker PowerPort 21-Watt folding array.

If you don't need 21-Watts, they offer a 15-Watt version that deletes one panel.

GoalZero stuff is well made but extremely overpriced on a dollar-per-watt ratio and larger than necessary for not using the latest cells. Anker is using SunPower cells.

Example: GoalZero Nomad 20, a 20-Watt folding array: $200 MSRP, compared to the $50 or so for the 21-Watt Anker PowerPort.

The only upside to the GoalZero stuff is it seems to output enough voltage for things like laptop or storage cell charging; with Anker, it's USB only.

I would also suggest one of these:

It's universal USB charger and power pack. The included 18650 Li-Ion battery can provide power to USB devices and the charger will charge most battery chemistries and sizes. (NiCad, NiMH, Li-Ion, AAA, AA, C, 18650, 18350, 10440 etc) Charge that with the solar array and then use it to power devices when the sun isn't out.

u/creekyoffgrid · 2 pointsr/solar

I really like the new Victrons. Blazing fast mppt. And you can add bluetooth monitoring/programming. Which is really nice.

u/nolyfe27 · 2 pointsr/solar

My system specs are: 8 12volt 100ah AGM batteries wired in series parallel to 48volts


Charge controller is Epever 80 amp mppt

It sounds like when you add milk to rice crispies cereal.... I have read AGM should make no noise. Thanks for the response.

u/tangakalol · 2 pointsr/solar

I have a 2018 ford transit van. We take this with us camping ( I camp about 20 times a year, 2-3 day trips ) .


I am looking to get a small electric generator / battery and a simple solar panel to charge it. This will be used just to run a water pump for once a day quick shower, power some low energy fans at night and charge devices.


I already own this power source -


I was debating getting this solar panel -

Is it compatible and will charge the power source listed above or is there a better one? Am I missing any critical components to get this to work?


I plan to mount it on top of the van as a permanent structure.

Thanks in advance.

u/drbudro · 2 pointsr/solar

Regular car batteries are made to have a lot of cranking power, and then stay on a trickle charge once the alternator gets going. Running the battery voltage down each night and charging it daily will kill the life of your battery (if it's not deep cycle).

Honestly, charging a phone (5w), running some small LED lighting (8w), and a couple 12VDC fans (6w) can all be done through your cigarette lighter port and won't be drawing more than 20watts. If you ran that all night, you would only be using 15amp/hrs or so of your battery; and if you get 8 hours of sunlight, you only need a 30watt solar panel to charge it back up. Whenever you are talking about solar though, you should plan on doubling your capacity to account for non-optimal performance, cloudy days, long winter nights, etc.

kieranmullen gives a pretty good rundown of what you would need to setup a separate 12v system but seems like overkill for what you are asking (and would run you about $300-400).

Personally, I would get a 100 watt panel, 7 amp charge controller, the cheapest 12v deep cycle marine battery from walmart, and maybe a 3-400w inverter (for a laptop charger or any other AC devices). Also, I'd put an inline fuse between my charge controller and load, and maybe another between the battery and charge controller.

u/rudykruger · 1 pointr/solar

Are you within the Amazon return window? Send it back.


That is almost certainly not a real MPPT charge controller, and it is way overpriced for what it is. The "PV Off" setting is where charging stops and the battery goes into float. A single setting is not enough, with this controller you will always undercharge and eventually ruin the battery prematurely.


A proper charge controller (MPPT or PWM) allows you to set a level for Bulk charge (i.e. approximately 80% charged), Absorption charge (the remaining 20% to full) and Float charge (trickle charge once full).


If you are on a budget, on the cheaper side get Epever or Renogy. This 30A Epever is a proper MPPT controller and is more than enough charge controller for your setup (with a 30Amp MPPT you can go up to ~400W of solar if you are charging a 12V batttery system).


With a 100W panel you don't need a 40Amp controller, or even a 30Amp controller. A 100 watt, 12V nominal panel (i.e. 18-20V PV) will produce around 5.5 amps, and a real MPPT controller might raise that to 7 amps charge to the batteries. This 15A Victron controller is vastly superior and can handle up to 200 watt solar when charging 12V batteries.

u/asanano · 6 pointsr/solar

500,000 tons of coal ~ 4 billion kilowatt-hours. Say solar panel lifetime is 30 years, producing electricity 8 hours a day. That means you need 45 kilowatts of solar panels. That means you need 22.5 Watts per pound of sand. A 100 Watt solar panel is [16 lbs] ( That would mean ~ 25% of a solar panels weight was silicon. Seems about reasonable.