Author Topic: Critique this controller  (Read 5656 times)

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Harold in CR

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Critique this controller
« on: January 13, 2015, 02:18:57 PM »

 Hopefully have a job coming up, where I can afford to buy 4 Solar Panels and am thinking an MPPT controller.

 Found this 40A on Ebay, (Yeah, I know, it's ebay) BUT, it's affordable for me, if it functions as I need it to.

 LINK

 I can't afford to mess up batteries, etc., so, is this worth taking a chance ?

 Thanks,  Harold

gww

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Re: Critique this controller
« Reply #1 on: January 13, 2015, 03:02:16 PM »
One thing that bothers me right off the bat is am open voltage maximum of 48 volts.

I wonder what they mean by the statement "mppt, charging is pmw"

I don't know but you need a 12 volt system and the cold wheather voc better not go above 48 volts. 

I really don't know
gww

Mary B

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Re: Critique this controller
« Reply #2 on: January 13, 2015, 03:21:41 PM »
The old saying, "you get what you pay for" comes to mind. Is saving $70 on a real charge controller worth frying a $100+ battery?

Harold in CR

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Re: Critique this controller
« Reply #3 on: January 13, 2015, 03:54:19 PM »

 As I said, money is VERY tight. I am always around to keep an eye on things, so, this is a learn and observe item.

 I know NOTHING about these things, and, just buying one from a store is much different than trying to find something I know nothing about, out here, in the jungle.

 As always, recommendations are extremely welcome, so I don't fry a battery. What can I get for that $70.00 more ? Please explain?

 The description says 12-24V. That's what I will have, in the beginning. It is lasted at 40A max, so, that will also be below my needs in the beginning.

 Thanks

gww

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Re: Critique this controller
« Reply #4 on: January 13, 2015, 04:09:52 PM »
i am not making fun, I have a $12 one with homemade solar panels on two car batteries at a rv parked at a creek.  I just know some of the cheeper IE: not made for pmw charging, solar panels have a voc of 44 volts.  48 volts is not far from 44.  I hooked the cheep one I have and it ain't blew up.  I just don't trust that you link is true mppt and I am not smart enough to figure it out for you so I am looking at it as if I wanted it.  I try some pretty wierd stuff cause I am cheap and some times it doesn't work out and I have to eat it.   Somebody might be able to tell you what you are buying.  I only noticed that one thing,  maximum open voltage of 48 volts.

No matter what, If you do end up with it I hope you give us your opinion after you have a chance to use it.  I am always scared cause I keep reading on these forums that sellers on ebay are calling chargers mppt that are not mppt.
That scares me but I don't know crap.

I wish you the best.
gww

joestue

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Re: Critique this controller
« Reply #5 on: January 13, 2015, 04:11:35 PM »
i'm not convinced its actually an mppt charger.

look closely and the photos show the comparison between it and the tracer2210, which weighs twice as much.

mab

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Re: Critique this controller
« Reply #6 on: January 13, 2015, 04:31:08 PM »
Well the Tracer has a big toroidal inductor and big capacitors - which is exactly what I would expect to see in an MPPT ; they're conspicuously lacking on the cheap controller, so I don't see how it can be MPPT.

I'd save my money and buy a cheaper PWM controller (that isn't pretending to be MPPT) and put any saved money towards more PV.

Harold in CR

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Re: Critique this controller
« Reply #7 on: January 13, 2015, 04:37:17 PM »
 I take no comments as making fun. I asked for Critique, and, that is what I am getting. I know nothing about this stuff, so, value any and all input. I truly appreciate all input, and, this is leaning heavily to NOT what it seemed to be.

 Thanks for all input. I did learn a couple of things, so, I have a little better feel of what TO look for.  The search continues.  8) ;D

 Mab, thanks for your input. Learned a little more from your input.

gww

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Re: Critique this controller
« Reply #8 on: January 13, 2015, 07:01:42 PM »
cr
This won't answer your question but is still being discussed and maby something will come up.

http://forum.solar-electric.com/showthread.php?26002-Cheap-MPPT-regulator-from-China-true-and-not-fake&p=210304&posted=1#post210304

gww

Harold in CR

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Re: Critique this controller
« Reply #9 on: January 13, 2015, 07:53:54 PM »
Thanks. I will keep an eye on that thread.

gww

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Re: Critique this controller
« Reply #10 on: January 13, 2015, 07:57:59 PM »
Did you see where bb said the one in the vidio is actually mppt?  100 bucks but maby only made for 12 volt bank.  I didn't watch close enough to remember but I do respect "bill" the guy that made the statement.
gww

Harold in CR

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Re: Critique this controller
« Reply #11 on: January 13, 2015, 08:03:25 PM »

 For $100.00, I would look for a name brand for a bit more. That cheapy was cheap enough to learn on, as I mentioned earlier. I will reread that thread.

 I really envy you guys that understand electronics.

phil b

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Re: Critique this controller
« Reply #12 on: January 13, 2015, 08:23:31 PM »
Harold,
If your solar panels are a little above the battery voltage and your going to be around the area, why not skip the charge controller? Hook them up directly to the batteries. Batteries can clamp the panel  voltage. On a 12 volt system, I look for panels that output ~ 20ish volts on an open circuit.

Phil

Flux

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Re: Critique this controller
« Reply #13 on: January 14, 2015, 02:00:25 AM »
The cheapest mppt controller that works is the Victron Blue Solar 75/15. I think it is way out of your price ( 90  in uk ). If you can't afford that then buy a reliable pwm controller and make sure your panels are suitable for direct connection and use heavy wire, the mppt is brilliant for reducing cable loss but on small systems the gain is otherwise marginal.

I bought something on ebay that was so cheap it seemed incredible , it was not mppt and I would never trust it for anything. There may be things that work at a bargain price but if cost is a big issue then it is a risky experiment. If you have a bit of money to gamble you may hit it lucky but if money is tight then don't risk it unless you can find someone who has tried it.

Flux


Mary B

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Re: Critique this controller
« Reply #14 on: January 14, 2015, 03:00:35 PM »
The Chinese copy a product design then start looking at it and removing components. By the time they are done it is not longer the same thing but they still use the original name. So I really doubt it is true MPPT and os more likely a PWM controller. PWM is fine for learning and can always be used as a load controller when you upgrade if you make sure it supports that option at purchase time like this one https://www.solarblvd.com/product_info.php?cPath=6_48_104&products_id=794

Harold in CR

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Re: Critique this controller
« Reply #15 on: January 14, 2015, 03:16:35 PM »

 Thanks for that link, Mary. I was around when the Japanese did then, what the Chinese are doing now. I don't like buying Chinese, only because everything is cheapened down to barely working items. A LOT of this is demanded by the people that want Chinese factories to build as cheaply as possible. I don't blame the Chinese nearly as much as the Companies ordering bulk stuff and being as tight about money as is possible.

 I am nearly ready to put the Lenz2 Turbine up, so, I will need a controller for that, also. Would like to find something where I can eventually run 2-3 wind machines, a hydro turbine and Solar PV, all on 1-2 battery banks. Then, use whichever has more available charge capacity. I can build wooden towers with wood as strong as steel, so, cost is low.

 Just need more batteries, before I get serious about turbines and panels. I'm working on Battery searching, now.

littleharbor2

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Re: Critique this controller
« Reply #16 on: January 04, 2017, 08:09:31 AM »
While I realise this thread is 2 years old I comment for the sake of anybody reading it now.
This is NOT am MPPT controller. I bought one knowing full well it probably wasn't so I could prove it to myself. If you for example connect a 24 volt 5 amp panel and a 12 volt battery you would expect 10 amps or thereabouts charging output, if true MPPT. It will in actuality charge your 12 volt battery something less than 2.5 amps. It is a decent PWM controller though with a very informative lcd readout.
2100 watt Suntech array, Midnight classic200, NEW (commissioned 2015) Trace SW 4024, 700 Ah @ 24 volt AGM bank, Bogart Trimetric and tons of Baja Sea of Cortez sunshine.

OperaHouse

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Re: Critique this controller
« Reply #17 on: January 04, 2017, 09:14:43 AM »
I grabbed this image somewhere.  Hey the board says MPPT, but there are no capacitors and inductors to store energy or transform it.  It is actually built pretty well, just not MPPT.  This footprint is typical of many cheap converters on ebay. 

littleharbor2

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Re: Critique this controller
« Reply #18 on: January 04, 2017, 02:36:48 PM »
Agreed.  In this case it appears that MPPT is just a brand name, for lack of a better term. "That's just what we call it, that doesn't mean it is multi power point tracking". LOL
2100 watt Suntech array, Midnight classic200, NEW (commissioned 2015) Trace SW 4024, 700 Ah @ 24 volt AGM bank, Bogart Trimetric and tons of Baja Sea of Cortez sunshine.