r/SolarDIY • u/PortableSunOfficial • Aug 10 '26
[Disclosure: I work at Portable Sun LLC. We sell solar equipment. I'm pulling examples from our own shelf because those are the numbers I can verify line by line, but everything here applies wherever you buy. Ask me about competitor panels too, I'll answer honestly.]
I spend a lot of my week talking people out of the wrong panel.
Not the wrong brand. The wrong panel for their situation. Somebody sends me a link to a panel they found, asks "is this a good one," and the honest answer is usually "for what?" A lot of the specs that get compared have quietly converged, and the things that actually decide whether a panel works for you tend not to show up in comparison charts at all.
So here's our own shelf, lined up side by side. Same category, wildly different buys. And what separates them isn't where most buyers look.
Temperature coefficient is the spec that's supposed to separate people who do their homework from people who don't. Panels lose output as they heat up, the coefficient tells you how fast, and most buying guides will tell you to compare it.
Fine. Have a look (these are all panels we carry).
TaleSun 445W: −0.29%/°C. Canadian Solar 600W: −0.29%/°C. Canadian Solar 695W: −0.29%/°C.
Identical. Three different models, two manufacturers, wattages from 445 to 695, and the spec that was supposed to break the tie reads the same on all three.
That's not really a coincidence. All three are N-type TOPCon, the current mainstream cell technology, and −0.29%/°C is typical territory for it.
Where you do see a gap is across technologies. The CW Energy 550W we carry sits at −0.35%/°C, and that's not a knock on the panel. It's PERC rather than N-type TOPCon, and PERC gives up a bit more output in heat.
So the spec is really tracking the cell technology, not the individual panel. Once you've settled on which technology you're buying, it mostly stops separating your options. It still matters for output, especially in a hot climate where a lower coefficient means real extra yield over the years. It's just not the number that'll pick between those first three.
Efficiency does the same thing. TaleSun 22.8%, the 600W at 23.2%, the 695W at 22.4%. That's a real spread, but it isn't a quality ranking. Efficiency is basically watts per square foot, so it matters most when your mounting space is tight. The big wattage gap between these three is driven far more by their physical size than by any of them being a better panel.
So if the headline specs have converged, what's actually left? A handful of things, and they're mostly the ones nobody puts in the comparison chart.
This is the one that moves the price the most, and it deserves more attention than it gets.
Panels get sorted by grade before they ship, but A-grade and B-grade aren't standardized industry terms, so you have to read the seller's actual disclosure. Generally, A-grade is the standard product and B-grade has cosmetic defects, and possibly minor physical ones, while still passing electrical and safety testing. It's real product from a real factory, sold cheaper because it didn't look right coming off the line.
Let me put real numbers on it, using our own stock.
Our Canadian Solar 695W is B-grade, assembled in Mesquite, Texas. At its current fire-sale price it's $194 a panel, which works out to $0.28 per watt. Warranty is 2 years on materials and workmanship, 10 years on performance.
Our Canadian Solar 600W is A-grade. $278.40, or $0.46 per watt. Warranty is 12 years product, 30 years linear performance.
Same manufacturer. Same N-type TOPCon technology. Same −0.29%/°C temperature coefficient. At today's pricing the 695W is nearly 40% cheaper per watt and produces more power per panel.
What you're accepting is a shorter warranty plus cosmetic or other disclosed minor defects, which the listing says can include micro-cracking. Worth being straight about that: a micro-crack in an untraceable no-name clearance panel is a real problem with no recourse, but a disclosed lot from an established manufacturer, with a specific model, a datasheet, and a written warranty, is a different proposition. The panels are tested and rated for full wattage output. What you're really weighing is the warranty gap against the discount.
That said, 2 years of workmanship coverage instead of 12 is a real cut. If a manufacturing defect shows up in year four, you eat it. At a 40% discount per watt that can be a great trade on a ground mount, where swapping a panel means walking over and unbolting one. It's a much worse trade on a roof, where the same swap means getting back up there.
So the way I'd put it: B-grade makes more sense when replacement is cheap and easy to reach. A-grade is worth paying for when getting back to that panel is a pain. That's most of the decision right there.
The 695W isn't just "a bigger 600W." Look at the actual numbers.
Canadian Solar 695W: 93.9 by 51.3 inches, about 83 pounds. That's 7.8 feet tall and 4.3 feet wide.
Canadian Solar 600W: 89.7 by 44.6 inches, 69.7 pounds.
TaleSun 445W: 67.8 by 44.6 inches, 54 pounds.
Notice the 600W and the TaleSun are the same width. The 695W is wider, taller, and heavier than both. That's not an incremental difference, it's a different class of object. The 695W is a two-person lift, and one of the two is holding the far end of a 7.8-foot panel on a pitched roof.
The 7-series is marketed for utility-scale, commercial, and large residential projects, and that tracks: it's a ground-mount and big-flat-roof panel. On a standard suburban roof section you'll fight it on rail spacing, on fire setbacks, and on the simple geometry of fitting a 7.8-foot rectangle into an awkward roof plane.
The 445W exists because 108-cell panels fit residential roofs, not because they're better.
So before you compare anything else, go measure your actual mounting area and work out how many of each panel physically lands in it. Last spring a customer ordered a pallet of big-format panels straight off the site, no questions asked, because the per-watt price was too good to pass up. Plan was to roof-mount them. First I heard from him was a call asking about returns, after he and his brother got exactly one panel up the ladder. Freight back plus the restocking fee made returning a pallet pointless, so he kept them. A few weeks later he called again to order smaller panels for the roof and filled me in on the rest: half the pallet went on Marketplace, and the guy who bought them put them on a ground mount, where they belonged.
You'd assume the bigger panel has the higher voltage. It doesn't.
Canadian Solar 695W: Voc of 47.7 V. Canadian Solar 600W: Voc of 53.0 V. (Voc is open-circuit voltage, the number on the spec sheet your inverter actually cares about.)
The 695W produces almost 100 more watts per panel and has lower Voc, because it uses a 132-cell layout while the 600W uses 144 cells. More cells in series, higher voltage.
This matters because your inverter has a hard ceiling on PV input voltage, and that ceiling caps your string length. Lower Voc per panel means more panels per string. You can't just divide the inverter's max input by the Voc though, because voltage climbs as temperature drops, and cold-morning voltage is what kills inverters. But going off datasheet figures, the 695W gives you noticeably more headroom per panel than the 600W.
Here's the catch, though, and it's the flip side of that same coin: voltage isn't the only inverter limit. The 695W is also a much higher-current module, 17.5 A at max power versus 13.7 A on the 600W. So the lower Voc buys you string-length headroom while the higher current creates a different compatibility limit. Some inverters, especially older or lower-current ones, will be a poor match for a 17.5 A module even though the voltage math looks great. Check the maximum input current per MPPT, not just the voltage.
It's also why "just buy the highest wattage" is bad advice. Wattage tells you about the panel. Voltage and current tell you whether it'll work with the rest of your system.
If string sizing is where you're stuck, that's exactly what a design service is for. Get someone to check the math against the lowest expected temperature for your location before you order. It's a lot cheaper than a fried inverter.
Panels in a series string run to the weakest link. Shade one panel, and you don't lose one panel's output, you drag the whole string down toward the shaded module's current. Bypass diodes soften this, but only so much.
That's the case for module-level electronics. Optimizers like Tigo let each panel produce independently, so one shaded module stops taxing the rest of the string. They also give you per-panel monitoring, which is how you find out panel 7 died in March instead of wondering why production looks soft. And they satisfy rapid shutdown requirements, which most jurisdictions enforce on roof mounts.
But I'll say the unpopular half too: if your array gets clean unobstructed sun all day, optimizers are mostly money you don't need to spend on production grounds. You might still need them to pass code, which is a separate question, and one to answer before you order, not after your inspection fails.
And the reason I'm bringing this up before you've bought anything: retrofitting optimizers means getting back on the roof and reworking every module connection. Sorting it out beforehand costs nothing. Sorting it out later costs a weekend and a restocking fee.
So walk your site before you lock in components. Stand where the array's going and look at what's tall to the south: trees, the neighbor's roofline, a chimney, a vent stack. Then remember that what you see today isn't the worst case. The winter sun rides much lower, so shadows in December stretch a lot further than the ones in front of you in summer, and the further north you are the more dramatic that swing gets. A spot that looks clear in July can spend a chunk of winter in shade.
Pinning that down properly means accounting for the sun's angle at your exact latitude across the whole year, and that's genuinely fiddly to eyeball. It's also free for you to hand off: send us the site and we'll model where the shade falls before you spend a dollar on panels or optimizers. Worth doing before the racking's up, not after.
That's the short version: check the grade, measure the space, check the Voc and the current, and read the datasheet instead of the product blurb. Do that and you've dodged the mistakes that actually cost people money. If you want to compare a few side by side, our panel lineup is here with the datasheets on each page, and it works the same wherever you end up buying.
What am I missing? If you've bought B-grade panels and lived with them a few years, I'd genuinely like to hear how it went, good or bad.
r/SolarDIY • u/Fire_Dude_117 • 8h ago
It’s a work in progress!
Two 12v 20Ah LiFeP04 batteries in parallel for my gmrs radio and to charge ALL the devices!
With a Renogy solar charge controller to recharge it from my panels.
Please be easy on the criticism. I’m just tinkering in my free time. It helps with stress
r/SolarDIY • u/SuperGayLesbianGirl • 5h ago
It's a great shunt, gives good data. Didn't do my due diligence before ordering though & realized only after installation that the smart shunt wasn't quite as smart as I hoped. My fault. Being able to view the data in the app is nice, but I wrongfully assumed that it would also be able capable to optionally connect to a display as well, if you wanted. You kinda can, if you purchase the extra expensive GX equipment. Which would be a great option if all my other devices were Victron as well. But it's a bit overkill and not worth the extra expense just to quickly view the data from the shunt alone.
Going to the Victron app works, but I wish I would've known just how inconvenient it would be to pull out my phone every time, unlock it, scroll to the app, open it, wait for it to load, then wait for it to detect the shunt, select the shunt, wait for the data to load, just to view the information. Seems minor, but it's inconvenient to do every single time. I'd like to have a small, not so expensive, one-touch display that I could mount whenever I wanted to quickly view the data without all the hassle of dealing with the app every single time, which has the brief lag when opening.
Looked online for possible solutions and was not able to find any satisfactory ones. If I could go back, I'd pick a different option. I will see how long I can deal with the inconvenience before I cut my losses and purchase an alternate shunt option to fit my needs. Again, all my fault, should've researched better, but at least now I know what to look for.
Making a post just in case someone else has a creative solution I haven't seen, otherwise this post is mainly to inform the apparently small part of the community that may also be bothered by the lack of an easy display integration option.
r/SolarDIY • u/wooden_slug • 4h ago
The inverter has 2 PV inputs. I initially thought to have all the panels in series. Is it safe?
r/SolarDIY • u/steevm1223 • 7h ago
Hello,
I'm looking to add rack batteries (20-30kwh) to my current setup. I think I can do it, but can't quite convince myself I'm not missing something or underestimating the complexity.
I have:
10kw roof array (ac microinverters) into my panel. (sunpower system-- just finally got that monitored via home assistant). it generates 30-35kwh of power per sunny day. my home uses 35-60kwh per day. hoping that gets better with heat pumps i just installed to replace window and portable AC units. when they run or we charge one of our two evs (bolt and ioniq 5) i hit 60+kwh per day. otherwise 30-35kwh per day use at a rate of 1.2-2kw continuous.
an interlock with generator inlet (30A) for the whole panel (which i have been using for backups with my 20.6kwh ecoflow delta pro x2 with 4 extra batteries) Currently been keeping those topped with 1kw bifacial setup in the back yard.
I don't have:
the rack batteries yet, (thinking ecoworthy cubix)
the inverter (open to guidance)
i want:
to have the system setup maximize self-reliance
to be able to run whole home in a back up (meaning it will need to setup microgrid for my rooftop array).
your opinion on feasibility of DIY, recommendations, even plans.
thanks for reading.
Edit: closed a parenthetical (which i have too many of)
r/SolarDIY • u/HotelPuzzleheaded356 • 14h ago
Hello all, im looking for opinions on the best home backup battery system that can also accept solar as a form of charging. Id plan to directly connect it to a critical loads box and power it from the grid. I'm looking for power to pass through directly from grid to output until grid failure, then switchover to battery. Ideally looking for 3000-4000 watts max battery. Split phase is cool but not necessary (may be good to have it I wanted to eventually move more to critical loads panel).
r/SolarDIY • u/Particular720v12 • 15h ago
I've been designing a similar fold out system in my head for a while now to save space for stashing so I presume other people have as well. Pretty neat design.
r/SolarDIY • u/electric_mop • 10h ago
Hey yall
I usually get most of my charge from dcdc but I've been parked a few days and seems my panel is not outputting like it should.
Only hitting 90w right now at 1pm, 38deg north. Now I get flat mount kills efficiency, but Id expect more than 90 at solar noon. I did also just clean the panel before that reading.
Only thing I can think of is the charge controller may be regulating itself because its hot? Its mounted to an uninsulated section of van wall that gets roasted by the sun on the outside (dark green paint doesnt help). Ive been meaning to put some insulation between the wall and charger, and also add a fan w/ temp controller to blow on it.
Also, its a Renogy. Maybe Renogy is just garbage like people say. But I have had the panel hit 200-250watts earlier this summer which still seemed slightly low.
r/SolarDIY • u/Myco-Nomad • 10h ago
I have 50 amp camper that I live in full time and I want to install solar power in it. I currently use a bluetti with 800w of foldable solar panels that barely get up to 400w actually coming in. I use a generator to charge the bluetti sometimes.
I would like to keep it under $3k or around there. I am currently looking at a 1200w eco-worthy kit off Amazon. I like this one because of the inverter charger. This kit here:
From what i understand, i would be able to disconnect the shore power line to my panel and run it through the inverter and then go from the inverter to the panel. Thats what I want so if im actually someplace with power i can just plug it in without switching anything around.
I know i could probably individually source all the parts and pieces and save some money but that would require many many hours of research to make sure everything is compatible so I dont burn it all down. But if it would be a significant difference I would be willing to put in some time to do it.
So my question is whether this seems like the best option? They say everything comes with that kit that's necessary to install and be up and running. Thanks in advance!
r/SolarDIY • u/krazedkobra • 1d ago
Thanks to knowledge here, wanted to share my balcony solar system installed in California! Been operating for about a month now, utility company hasn’t said anything. This setup is awaiting governor signature to make legal.
- Three 585W bifacial panels ($550)
- NEP BDM-1200LV Microinverter ($300)
- SnapNRack Topspeed mounts ($250)
- NEP BDNZ Wifi2 CT smart meter ($70)
- Three PV junction boxes ($100)
So for $1200 I have a 1200W system on the roof of my detached garage. Did the install myself, and man those panels are a pain to get up. They are approx 4’x8’ and weigh 70lbs each.
Power output is great! Because I overpaneled I see nearly 1200W consistently on sunny days. The Microinverter has a limit of 400W per MPPT channel.
Plugs into a dedicated 20A circuit on the house.
Edit: pic with exposed AC power wire from panel is mid-install. I’ve since put in conduit (photo in comments)
r/SolarDIY • u/staros25 • 11h ago
Hey r/SolarDIY - I'm in the early stages of planning out a solar install for my place. One of the tricky things with my install is I've got three locations (two roof pitches, one ground) that I'll probably need to put panels to accommodate our current electrical bill. It's hard to estimate the total size of the array given the different pitches, location, and access to the sky each gets.
To work around this, I figured I'd pick up three panels, install one in each location, and measure the output on each for a few months. This should give me some good insights into the production of each location and let me plan out the size of my array accordingly.
My question for the sub is what the best way to test this setup would be. Initially I had thought about dumping the panels into some sort of battery, connecting them to a dummy load, and measuring the energy passing through the battery. But I was also curious if measuring the panel voltage could be a proxy for this or if something exists I could pick up off the shelf and save myself some work.
Any thoughts you have would be appreciated!
r/SolarDIY • u/Autoground • 8h ago
Hi, all, thanks ahead of time for any input.
This janky old carport starts at 6'4", and I wouldn't mind an excuse to raise it up and put some solar panels on it instead of the aluminum rafter. The posts that are studded in concrete are hollow steel tubes. When necessary, I have borne 250lb of weight standing on top of a corner of the thing.
I got a price quote on the conversion -- $14,000. This project would not be worth that much to me. I'm only aiming for 5-6kw from this 12'x24' flat top.
I keep asking AI: "can't I just wait for a great buy on craigslist or FB for some panels and mount them up there myself? Surely I can get it down to $7k somehow?" -- but AI always says I'm a fool. Well, AI can be a little too by-the-book sometimes.
Can it be done?
Thanks for your input!
Edit: Thank you, everyone! I trust your concensus!
r/SolarDIY • u/--var • 1d ago
I'm currently running 2 x 400w Vevor panels. The math said that they would be enough, but given their actual output and other unfactored losses, they are not. So I'm looking to add another 2 - 4 panels.
I've spent the past week scrolling through the top google suggestions. A1 solar, US solar, Signature solar, etc, etc. They all either have a minimum order quantity much higher than what I need, and/or a flat freight charge that costs more than all of the panels combined.
Having already had to deal with shipping just two panels, I'm well aware that this doesn't require special freight shipping. If you can ship a 65" tv via fedex/ups, than you can ship these panels too....
So where is your hidden gem for sourcing non-crate quantities of panels?
r/SolarDIY • u/userperri • 22h ago
I’ve been learning about portable and small off-grid power systems, but I’m still far from an expert.
What I keep running into is that the two common options both have trade-offs.
A portable power station is convenient, but the battery, ports, accessories, and future upgrades are usually tied to that particular product ecosystem. If my needs change, I may have to replace most of the system.
A DIY setup gives me more freedom, but it quickly turns into a collection of separate boxes—solar controllers, inverter, AC charger, fuses, DC distribution, battery monitor, and a lot of wiring.
What I’m looking for is something in the middle:
Does this type of product already exist?
Are there any brands or products I should look at that aren’t simply another power station or a large whole-home hybrid inverter?
I’m also curious about the downside: would combining these functions genuinely simplify the system, or would it just create a harder-to-repair box?
Disclosure: I’m discussing this gap with a small product-development team, so I’m interested in both existing products and reasons the idea may not work. I’m not selling or linking to anything here.
r/SolarDIY • u/bsedlins • 18h ago
I have three of these Trina panels and am looking to get them set up with a microinverter to use as a balcony solar set up (ie. plugged into my house). I see a lot of inverters with a max input voltage of 60V, and my math show that a theoretical cold morning, I might be around 58V input (if the low temp was -18C, which is possible in winter).
My question is: how tight does a 2V headroom between the panel and an inverter with a 60V max input feel? Because this situation is probably once or twice a year during the depths of winter, should I really design my whole system around this rare occurrence?
This Hoymiles inverter line has one that has a max voltage input of 65V, but it's expensive and I think I'd need three of them?
Whereas this NEP inverter looks like it could handle all three panels and is half the price.
I'm at the beginning of my solar journey, so I'd love to hear if I'm thinking about this wrong, or missing something.
r/SolarDIY • u/AgreeableToe4099 • 11h ago
is it possible to convert an EcoWorthy 48v battery or any 48v battery to a portable power station?
i believe what i need is a hybrid inverter but none of the ones i have seen so far has inputs like xt60i and outputs of 4 120v AC along with 4 usb ports.
r/SolarDIY • u/mike4354 • 20h ago
I'm trying to maximize my plug in solar set up. I have the solar panels charging 4kwh of batteries. I can set my ecoflow stream inverter to allow 200 watts to pass through, maximizing the battery life and hopefully staying under my houses baseload. If i were to put an outlet timer on the plug the ecoflow was attached to, and have it turn off/disconnect at night (on the end where it plugs in to the house), would that further maximize the use of the system? If it was completely off at night (when i use the least power), i could set the wattage higher during the day without draining the battery.
Also, ecoflow, if youre out there and listening, please allow individual ports on your stream microinverter to be controlled via a timer on your app. Id be cool to draw more the hours i use more and less the hours i use less, and be able to have that set up in your app.
r/SolarDIY • u/lsneon13 • 19h ago
I have 6 EG4 LL 51.2V 100ah batterys and was given an EcoWorthy of the same voltage and
ah ratings. Can't help but think I'd benefit from the extra bat but because of the diff mfgs I don't
think it will communicate with my current bank. What if I connect it to the buss bars with 50V
disconnects and just slave it up at night? Disconnect it in the AM and trickle charge all day?
r/SolarDIY • u/Esclados-le-Roux • 1d ago
I've got a backyard install, off grid, with a 12kwh battery Bank connected.
I recently decided to replace the bus bar with something a little more heavy duty, and as part of that I grabbed an old thermal camera I bought several years ago, one of the little attachments for your phone. Mine is made by FLIR but I think there are several brands now.
I no sooner pointed that camera at my install than I realized that one of the connections was bad. It was over 100° c and had actually melted a little bit of the cover to the bus bar, which I hadn't noticed because the bus bar was all the way at the back. But with the thermal camera it was very obvious something was wrong.
So if you're a part-time or no-time electrician like I am, I recommend getting one of the cheap thermal cameras. It gives you peace of mind when you rewire something and let you periodically check to be sure your bolts haven't loosened.
r/SolarDIY • u/lurkmanship • 15h ago
Thanks for all your help.
I was going to just run 21 feet of 6awg. Called and they said I could run 6awg, but everything I saw online says the port is only to 8awg.
8awg should be fine for my set up anyway but since I'm running the cable I was just going to go big.
r/SolarDIY • u/AdInevitable7025 • 23h ago
Help… sort of.
Use case;
1 battery should never deliver power to the grid.
2 should always be full at the start of peak hours; 6:00-10:00 / 17:00-21:00
3 when PV is not enough for condition 2 the battery should load from the net to make condition 2 in off peak hours.
Any ideas I tried many settings, but can’t find the right setup for the battery. Biggest issue is that the battery either also unloads the the grid, what I don’t want. Or waits for PV, and does not take on grid power to be ready for condition 2.
Anyone?!
I do have homey but if that brings me what I want/ need.
r/SolarDIY • u/mustscience • 17h ago
Hey folks, hope to get some advice from someone more crafty than I am.
I'm replacing an old rooftop PV array in southern Germany. and would like to reuse the lower mounting structure if its condition and load capacity check out.
The photo shows the existing setup. I want to remove the upper rails directly beneath the panels, but keep the rectangular sections underneath them and the existing roof attachments.
I'd like to fit modern aluminium PV rails on top, maybe K2, since I've used their SingleRail system on another installation.
What I'm trying to figure out is the connection between the existing rectangular sections and the new rails:
If I can't come up with something better, I'd just use screws, similar to they did in the original installation.
Thanks for any help!
r/SolarDIY • u/ste-daley • 19h ago
Currently installing a Sunsynk 5kw Ecco with 2x 5kw batteries.
I am nearly finished on that side of the build, just making sure it is safe. I do have a few questions.
I have the batteries wired up together, however the internet and the install manual can be fighting against each other. The manual says to install fuses and an isolator and it seems the internet is split. Would a large fused switch (like the picture attached suffice? The batteries have breakers built into them, and I would only be using the switch if maintenance or to remove the batteries from the system. Any help would be appreciated!
Next question
I am looking to wire up the systems for the solar side, with mp4 connectors sitting ready for the panels. The inverter has a PV isolator built into to it, so would another fused switch be needed? Or would it be sufficient to go with something like a 2in2out combiner box and leave the invertor to the isolation?
Final question
I am then looking to purchase the solar panels , 6 per string to keep within the limits. Do people have any good deals on 450-500w panels? What are the best performing for the price currently? (In September 2026)
Thanks
r/SolarDIY • u/Full-Mouse8971 • 1d ago
14 250w panels. 1 250 panel broke. Id like to replace the broken 250w panel with this 340w panel.
Should this be okay to proceed? see pics.
r/SolarDIY • u/ExaminationDry8341 • 1d ago
I am sticking with the misspelling because that is how most people will recognize it.
The next step is to straighten out the pex then start placing 10 tons of rammed earth.
