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Old 03-20-2021, 10:54 PM   #1
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MPPT Choice?

I have 6 100 watt solar panels. I am not sure if I will be going with AGM or Lithium batteries yet.

These are the panels I have.

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Would this MPPT be a good choice to use? I want some wiggle room of course.

https://www.amazon.com/EPEVER-Contro..._t1_B081JWQJZL

Thanks for any help or opinions. My head is spinning learning all of this.

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Old 03-21-2021, 12:01 AM   #2
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I struggle with this too, but from a very basic electrical math perspective, it seems that if you have 6 x100w panels, that gives you 600w max.

600w / 12v = 50a, so seems you would need a charge controller that can handle at least 50a.

Since you are not sure what battery type you're going to use, a controller with selectable type, which most seem to have, is a good way to go.

I have two general rules when it comes to buying things that are expensive.

1) Over-buy. Example, I can get by with a 2000w inverter/charger at $900, but for $1200 I can get a 3000w. So, for 33% more $ I get 50% more wattage. Seems like a smart upgrade. If I never need it, oh well, but if I do, then I don't need to scrap my $900 investment and shell out another $1200 ($1400 with inflation) later.

Since you have 6 panels at 100w, and you may find you want more wattage down the road, it would be very easy for you to swap out the 100w for say 200w panels. Now you are pushing 100a. So, while you want 50a min with your current setup, you may want to consider a higher amperage controller for efficiently managing your 50a setup and be expandable down the road.

2) When it comes to buying a product that is not necessarily name brand, even if it is, I look at the percentage of 1 and 2 star ratings. Anything over 10% of the total is automatically eliminated. Especially if there's very few reviews.

Your listed mppt controller has 107 reviews, of which 14% 1/2 stars.

So, in answer to your original question, I'd say no, that's not a good controller.

Hope this helps.

Best of luck.
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Old 03-21-2021, 12:28 AM   #3
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Your listed mppt controller has 107 reviews, of which 14% 1/2 stars.

So, in answer to your original question, I'd say no, that's not a good controller.

Hope this helps.

Best of luck.
Thanks for helping. I guess I am back at square 1 for the 4th time. Now I have no idea what MPPT controller to buy.

I kept hearing that that brand was the best bang for your buck. Hmmm...

I have looked at Victron MPPTs but the price of that brand is through the roof.
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Old 03-21-2021, 12:52 AM   #4
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Depending upon what your budget is, I find that the Midnite Solar Classic charge controllers are hard to beat. Rock solid, well designed, and gorgeous (if that matters). We use them in our builds, where we can. The Classic 150 is just a touch over $600 new, but there are used ones on eBay and I wouldn't hesitate to buy one used. Their quality and support are hard to beat.
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Old 03-21-2021, 01:02 AM   #5
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I feel ya.

Try this, middle of the road.

https://www.renogy.com/rover-60-amp-...gaAsYCEALw_wcB

Goes with your panels. If you have issues, hopefully since they are the same brand you'll get better service. Or, you can call and ask for some guidance.

Buying my bus at $2,300 was in some ways the cheapest part of my build!

$2,500 for different gearing.
$1,3000 inverter/charger
$350 furnace
$300 two starter batteries
$300 two (initially) house batteries
$200 for my cooktop
$700 - 1000 for a 12v refrigerator/freezer...if I go 12v. $200 if 110v.
$250 for new fluids and filters all around.

Undetermined amount for the propane system, all those damn pex pieces, foam for my cushions, cloth for my cushion covers, etc..

Thankfully I live in a target rich craigslist area for my flooring and cabinet plywood, kitchen sink and faucet, free dresser that I reused the drawers from.

I haven't even gotten to solar yet. But, I'm guessing $1,000 for the mppt controller and panels. That doesn't count all the little do-dads (shunt, battery switch, fuses, big wires).

BUT, compared to what it would cost to buy a fully set up RV, especially a diesel pusher like mine, I'm still coming out way ahead, maybe $10,000ish total.

Oh, but then there's the fuel, tires, maintenance and insurance....and that's if all goes well. Wait, am I talking myself out of this?? Naw. I'm too far in.

Plus, all the fun of researching, being frustrated, learning and still not feeling like I understand, no extra time to do fun stuff (upside of covid...bus time!), my relationship (meaning with my bus). Yes, some sarcasm included.

I really found out who my friend was (yes, singular). Thankfully he loves diesels engines and knows a ton (commercial refrigeration specialist) about plumbing, electrical, gas (propane) design, etc..

And, wouldn't you know it, I have the one dog who absolutely hates my bus. She literally runs away from it. All her dog friends bound up and love being in it.

Bottom line, if you don't have the money to go name brand, go no-name, just balance the reviews with the money...otherwise, it could easily be pay me now or pay me later.

Best of luck.
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Old 03-21-2021, 01:16 AM   #6
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Thanks I added the Renogy to my list of possible. But strange thing. I go look at it on Amazon and it has 14% 1 and 2 star reviews too. I wonder if MPPTs naturally have high 1 and 2 star reviews?

https://www.amazon.com/Renogy-Solar-...-garden&sr=1-1
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Old 03-21-2021, 02:13 AM   #7
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Victron is dirt cheap compared to the other quality brands

and their pricing model gives amazing flexibility.

Maximise your wattage **actually into your bank** per square foot.

Anything cheaper than Victron will not cut the mustard, not in efficiency nor in features and programmability in caring for whatever chemistry you want to buy over the years.

Rather than buying an SC to match your panels, IMO better to go the other way.

Say 75/15, look for a solid house style panel at 40+Voc, up to 250W or even a bit more if you find a real bargain locally.

1:1 ratio is best for handling any partial shading.
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Old 03-21-2021, 08:25 AM   #8
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Roy, you do not say what voltage you are going to work with.
I have EP solar and it works fine with me.

There are some new thought from a company electrodacus that does not use charge controllers at all.

If so inclined ,read up yourself, and make your own judgement.

In general I try to buy equipment that can be repaired or at least is not potted. Everything will fail at some moment

Withe current much higher efficiency cheap solar panels it is cheaper to add an extra panel then be worried about the most efficient charge controller.

Autorange charge controller will go to the lowest voltage if you accidentally drain your battery down to "nothing".
I had that happen when our 24v lead acid got drained down to 4 volt after snow covered the panels for several weeks and I was not there for a check up. It charged backup to the 12 volt setting and I had to give it a jump before it recognised a 24 volt bank...

Anyhow, you will find many opinions here, read up as much as you can.. diysolar,..will prowse,. And others can give you a good start to learn the lingo.

Good luck,
Johan
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Old 03-21-2021, 11:47 AM   #9
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If you plan on boondocking in dry/dusty conditions, like I want to eventually, anything that is fan-cooled will probably have a shorter life than equivalent items without fans. In those conditions fans make everything inside very dirty, and this could affect its function and reliability. For this reason I chose two Morningstar TS-MPPT-60 charge controllers for my solar array - they have large cooling fins that easily dissipate whatever little heat they produce.

I suggest buying a reputable brand that has good customer support in this country, in other words not the here-today-gone-tomorrow brands with unpronounceable names that only Amazon and Alibaba sell!
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Old 03-21-2021, 12:07 PM   #10
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In addition to the Midnite Solar I mentioned, I second Iceni_John's recommendation of Morningstar. I've installed both brands (along with Outback) in remote village electrification systems in India, where reliability was key. I highly recommend all three of those brands.
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Old 03-21-2021, 12:15 PM   #11
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Quote:
Originally Posted by RobOfYork View Post
I have 6 100 watt solar panels. I am not sure if I will be going with AGM or Lithium batteries yet.
I think you should make the battery decision first before deciding on the MPPT. What do you think your budget would be for batteries? Depending on how hands-on you are willing to go, lithium can be cheaper than AGM- and I don't just mean over the life of the pack or cost per watt-hour. I'm helping another forum member build out a 24V system with a custom 8S LiFePo4 bank. It was lower cost up front than the 12V AGM configuration they were looking at with higher capacity.

I'm slowly moving from the camp of "its silly not to look at lithium" to the camp of "its silly to even consider AGM if lithium is an option". Of course the 12V "drop in replacement" LiFePo4 batteries are still really expensive but some people want the warranty and convenience. Me, I'd rather do it myself, get the extra bang for buck, and have extra cells on hand to do my own service instead.

Quote:
Originally Posted by RobOfYork View Post
Would this MPPT be a good choice to use? I want some wiggle room of course.

https://www.amazon.com/EPEVER-Contro..._t1_B081JWQJZL
I'll be the second to say that Victron is probably one of your better options.
https://www.amazon.com/s?k=victron+mppt+50a
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Old 03-21-2021, 04:32 PM   #12
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After reading thread after thread and doing more research I think I am going to bite the bullet and just buy the following MPPT for my 600 watts of solar panels. Hate spending so much but...

Victron SmartSolar 150v 60a tr model at $540.00 ouch

https://www.amazon.com/Victron-Smart...garden&sr=1-13
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Old 03-21-2021, 04:43 PM   #13
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Originally Posted by RobOfYork View Post
After reading thread after thread and doing more research I think I am going to bite the bullet and just buy the following MPPT for my 600 watts of solar panels. Hate spending so much but...

Victron SmartSolar 150v 50a tr model at $540.00 ouch

https://www.amazon.com/Victron-Smart...garden&sr=1-13

The 100V version is far less costly, do you plan on wiring all of the panels in series or something?

https://www.amazon.com/SmartSolar-MP.../dp/B073ZJ43L1

I would recommend figuring out your batteries first, then choose an MPPT. If you went with 24V system for instance, you'd only need something capable of 25A.
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Old 03-21-2021, 05:27 PM   #14
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Had a typo in my post. 50 amp should have been 60 amp.

Batteries will most likely be Lithium setup as 12 volt unless budget gets in the way.
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Old 03-21-2021, 06:42 PM   #15
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Listen to katzukai... Why such a high solar voltage. More lower voltage panels in parallel is better for shading.. 24v battery is better for the inverter wiring and efficiency.

Good luck, Johan
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Old 03-21-2021, 07:19 PM   #16
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Listen to katzukai... Why such a high solar voltage. More lower voltage panels in parallel is better for shading.. 24v battery is better for the inverter wiring and efficiency.

Good luck, Johan
I am not wiring all 6 panels in series. I'm wiring each set of two panels in series. Then the 3 sets in parallel.

I know nothing about 24 volt systems. When I was researching solar the only things mentioned have been 12 volt. That's what made me choose 12 volt. Had to quit researching and start doing or it will never get done.
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Old 03-21-2021, 07:27 PM   #17
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Roosvtaylor, got to ask, especially because my wife is from India.. how did you get involved in India and where?
Johan
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Old 03-21-2021, 08:14 PM   #18
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I know nothing about 24 volt systems. When I was researching solar the only things mentioned have been 12 volt. That's what made me choose 12 volt. Had to quit researching and start doing or it will never get done.
Didn't sound like your research was over

Higher voltage systems do come with lots of advantages at the cost of some additional complexity (to power 12V appliances you need something to convert the higher battery voltage down to 12V). Price of cabling/components is an advantage:
Like I mentioned, you could get away with a 30A MPPT on 24V. Lower current draws, and therefore more efficient components is an advantage. Better efficiency from your batteries is an advantage (typically your battery's capacity rating is at a specific C-rate or lower discharge).

EDIT: A particular disadvantage (of 24V) with the panels you chose is that you'd have to wire at least two panels in series, 3 parallel to reach charging voltage. This means you would always need to have an even number of panels.

Not saying its for everyone. If you are looking at AC or DC loads, or charging at or greater than 1200W, or you expect current draws > 100A at any point in the system, or have an inverter 2000W or greater, its a good idea to at least look into a voltage bump. If you're just charging devices, running lights and a pump is probably not worth it.
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Old 03-21-2021, 11:27 PM   #19
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Everything I am using is 12 volt. I won't have anything 110 AC that is on for any length of time. Maybe a Insta Pot for 5 minutes every few days. Draws 1000 watts.

I am going with a 2000 watt inverter for the rare AC needed.

If I had the luxury of time I would keep learning for several more months. But I don't. I need to finalize the build and get it started.

I do appreciate your help. It gets me thinking.
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Old 03-22-2021, 12:07 AM   #20
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Roosvtaylor, got to ask, especially because my wife is from India.. how did you get involved in India and where?
Johan
What part of India is she from? It's an amazing country of extremes...and I loved my time there. I had two cycles of a 5-year business visa for India, where I was doing work for a wind turbine manufacturer...in my second career. I did project management and training, for both wind and hybrid (wind/solar) projects. In Rajasthan, out in the desert south of Jaisalmer, I worked on wind powered telecom projects for Bharti Telecom. In the south, I worked on village electrification projects funded by the Tamil Nadu state...in areas around Chennai and Coimbatore. And I taught classes to technicians in Delhi, Bangalore, and Mumbai.

A funny story your wife might appreciate. Cricket is huge in India and the Captain of the New Zealand cricket team, at the time, happens to share my name... Ross Taylor. And during the off-season's IPL league play, Ross Taylor served as the Captain of the Delhi Daredevils cricket team. So, everyone knows his name. I spent years disappointing hotel staff, who'd see that Ross Taylor was checking in...only to find me arriving.

Okay...back to discussing MPPT controllers!
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