Best, cheap MPPT charger controller?

[brahmon]

Hi guys.  Thank you all for saving me from potential disaster with my proposed upside-down roof mount ac project.   

I originally started with a 100 watt renogy solar kit with PWM but been quickly adding panels.  I'm up to 400 watts and will probably add 2-300 more.   

Looking for recommendations on a cheap good MPPT.   There's a bunch on Amazon for $30-$50.   What's a good one?

Thanks!

 

[Trebor English]

Beware of internet, eBay, and Amazon ads for controllers called MPPT.  If they are under $60 they are probably not MPPT.  Look for products over a pound with a fan for cooling.  MPPT controllers have substantial electronics that cannot be done in a 3 ounce product.  The electronics will dissipate heat.  It is possible to dissipate the heat with good fins and no fan.  My cheap controller is PWM, doesn't dissipate much heat, yet it has real looking cooling fins.  They are plastic, not functional and very light.  An actual fan costs money and it is unlikely they'll put one in if it isn't needed.  

MPPT controllers take higher voltage and make more amps out of those watts.  You might think that a product with a 40 volt input limit must be MPPT.  My cheap PWM has a high input voltage limit.  Using my PWM controller with a 60 or 72 cell panel will work.  The efficiency would by horrible.  There would be no additional amps.  Read the ads critically.  Ask yourself if a PWM controller could fit the description you are reading.   It would be a shame to pay $50 for a controller worth $12.  

Just because a controller 1) claims to be MPPT, 2) weighs two pounds, 3) has a fan, 4) has a price over $60, meeting all the points on my list, doesn't assure that it really is MPPT.  If it misses any one point I can assure you it is probably not MPPT and you will be disappointed.  Victron and Epever make some real MPPT controllers at low prices, $120 and up.  There are some under $100.  Other people will give recommendations.

 

[brahmon]

Thanks for the good info Trebor.  I also just watched Bob's new video.Perfect timing!   

I think I'll take yours and
Bob's advice and buy American!   Gonna buy the Renogy Rover on sale for $131!

 

[wmyers4u]

I would strongly consider a 40 amp MPPT that will work with 12 and 24 volt panels. It'll give you so many upgrade options you would probably never outgrow it.

 

[highdesertranger]

ah Renogy is not made in the USA. highdesertranger

 

[Trebor English]

In another thread jimindenver made this recommendation:

There are MPPT controllers that sell for under $100. My favorite is the Eco-Worthy 20a MPPT controller that can be had for $69. I have used them for over 5 years.

 

[B and C]

OP is talking about up to 700 watts in panels. A 20 amp unit won't cut it or will need to buy another one and run them in parallel.

 

[jimindenver]

The Eco-worthy 20a MPPT is $69 on their site. The Eco-worthy 40 amp MPPT is $96.32. It does not have the bilt in display but not only can it use a remote panel, it has blue tooth like Victron's do. Pay attention to the 50 Voc limit.

Eco-worthy 40a MPPT

 

[terranaught]

I've got an 2 40amp renogy rover, and another that looks the same and works the same but different color and name.
they all work very well, I have one with 1200 watts of panels feeding a 24v bank, 4 facing ESE and 8 facing S.
one is in the van with 400w 12v bat, and one in the shop 600w 12v bat all nominal 48v string.
no problems with any of them so far ( 2years total for all 3).
I think the battery connections should be more robust.

 

[Weight]

going with that much solar why cheapen out on a controller? Go to Morningstar MPPT.

 

[grahampa]

I did end up going with the eco worthy 40a plus bluetooth just last night. Hopefully will get it set up this weekend. Let you know how it goes. Was about 40$ cheaper than other models with Bluetooth functionality

 

[brahmon]

Isnt this "CHEAPrvliving?"   lol

My wallet is not deep so I am frugal by necessity.

 

[B and C]

Sometimes being cheap leads to pay me now or pay me later. In this case it could be a lot shorter battery life so that would be a pay me later scenario.

Sometime cheap means putting in more up front for longer lived products.

 

[brahmon]

You're right.   But it's all relative.   To me, I weigh the cost v benefits and value.   A $500 Morningstar cc is not 4X better than a "cheap" $135 Renogy.

 

[Weight]

Yes they are.

 

[brahmon]

please tell me how.   i'm a noob and willing to learn.

 

[Weight]

It's a long story. short version, there is a limited amount of energy captured by solar panels. Quality charge controllers get more of that energy into the battery bank. quality controllers use quality, more robust, components. Morningstar is a quality manufacturer, Renogy, while making decent products, is the lower price spread.

 

[brahmon]

What are the numbers?   Does the Morningstar convert 50% more than the renogy? 

You gotta do better than that bro.

 

[B and C]

You asked for advice and we are giving advice.

You can do as you please with it.

 

[brahmon]

jimindenver, thx for the recommendation on the eco worthy. will it work if you decide to add more panels?

thx all for all the good tips. im still learning and sorry for all the dumb questions. it's exciting to learn from you all and then execute that new knowledge!