Solar set up

Submitted: Thursday, Feb 09, 2012 at 07:49
ThreadID: 91756 Views:2691 Replies:7 FollowUps:12
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I'm about to purchase new panels and I'm looking for an MPPT controller. I am putting a 32a amorphous panel on the roof and want a mono folding panel as portable. Firstly, does anyone know anything about or recommend the following..ebay seller? They seem pretty cheap (too good?). I'm after 160w or greater.

Second, a member has MPPT controllers going for $100. Does anyone have any feedback on them? I'd rather buy from a member if possible.

Cheers,

Mark
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Reply By: Member - Phil G (SA) - Thursday, Feb 09, 2012 at 08:03

Thursday, Feb 09, 2012 at 08:03
I bought a 120W folding panel from the same seller last year. Very happy with the value for money - panel works fine. The cheap controller it came with regulates to 13.7V which I think is a bit low, so I run it through a Ctek 250S with MPPT controller. The leads it came with were too thin, so I upgraded it to 12Ga marine twin cable. And the self tappers holding the hinges together looked like they'd rattle apart so I replaced them with rivets. Panel itself works very well, looks to me to be pretty solid.
AnswerID: 477329

Follow Up By: silkwood - Thursday, Feb 09, 2012 at 08:17

Thursday, Feb 09, 2012 at 08:17
Excellent feedback (and fast too!).

Thanks for that Phil.

Cheers

Mark
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Reply By: Member - Niss42 - Thursday, Feb 09, 2012 at 11:01

Thursday, Feb 09, 2012 at 11:01
G'day Mark.
Mono much more efficient than Amophorous.

http://www.energymatters.com.au/choosing-solar-panels.php

What roof are you installing the 32A Amophorous panel on ?

Cheers,
Barry
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Follow Up By: silkwood - Thursday, Feb 09, 2012 at 22:11

Thursday, Feb 09, 2012 at 22:11
Depends how you define "efficient" Barry. If you mean power per m2 then yes, the mono are far more efficient.

What roof? On the top of my Delica. They're tall and skinny so, being closer to the sun the amorphous panel will increase in efficiency! ;-)

Cheers,

Mark
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Reply By: Battery Value Pty Ltd - Thursday, Feb 09, 2012 at 15:39

Thursday, Feb 09, 2012 at 15:39
Hi Mark,

so that's a 12V/32W amorphous panel right?
If that's it, then just parallel it with the 12V/160W folding panel.

Because the two types have different max power voltages, neither the amorph nor the other panel will actually yield max power, but pretty close to it nevertheless.

The member who sells state of the art MPPT solar regulators, can only recommend his product, which is the one and only unit having all relevant features.

And to bag Phil G's MPPT regulator: it's overpriced, and secondly it'll ruin any good battery in the medium term under the right(wrong) conditions.
Yes, that's right, it'll over-charge the battery if there's a surplus of solar energy available from the panels, with any small loads like fridges running concurrently.
This unit can't handle load currents during solar charging, which is a design weakness.

cheers, Peter
AnswerID: 477360

Follow Up By: Member - Phil G (SA) - Thursday, Feb 09, 2012 at 21:23

Thursday, Feb 09, 2012 at 21:23
A good business member doesn't bag the competition's products.
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Follow Up By: Battery Value Pty Ltd - Thursday, Feb 09, 2012 at 22:01

Thursday, Feb 09, 2012 at 22:01
Don't worry Phil, you probably were mislead by a fair amount of hype and misinformation surrounding most products in the leisure 'industry'.

And I'm sorry that I don't fit your definition of a 'good business member'....

BTW, we prefer to pass on real information over hype and deceit, when selling our gear.

Fair dinkum never dies with some.

cheers, Peter
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Follow Up By: silkwood - Thursday, Feb 09, 2012 at 22:01

Thursday, Feb 09, 2012 at 22:01
Pretty sure I agree with Phil here, there are better ways to put your point I think. Still.

Here's something I hadn't heard before, both panels attached together will mean neither achieves maximum power? Would it be better, then, to simply unplug the permanent panel before attaching the portable? Or would the two together outweigh the loss?

Peter,I notice you have 125ah AGM batteries. Would this be a good match with my Remco 100ah?

Thanks for the info people, After getting feedback and doing a (little) research I've ordered the 240w panels from Ebay. Here's hoping!

Cheers,

Mark
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Follow Up By: Battery Value Pty Ltd - Thursday, Feb 09, 2012 at 22:36

Thursday, Feb 09, 2012 at 22:36
Hi Mark,

problem is the dissimilar makeup of the silicon - one's in crystalline, and the other in amorphous state.
This results in slightly different thermal properties, causing different max power point voltage variations with temperature.
Instead of one camel back, you get two, and the MPPT solar regulator tracks the bigger one.
To answer your question, It's probably better to have them both connected, because the taller of the two peaks gets pushed up somewhat by the additional power (although not max power) from the smaller panel.
But once both panels are connected, you can use the optional display which gives you current, voltage, and Ah and Wh figures on the solar input. By momentarily disconnecting one panel, you immediately get to see the change in incoming power. And you also get to see the change in charging amps (the most important figure to watch when tuning the system).

And yes, our batteries are exactly the same chemistry as the Remcos, so no probs wiring them in parallel.
I just noticed you bought 240W of folding panels....
Our true MPPT solar regulator has an electronically limited max charging current of 10A, so it can't access the full 14A peak which would be available during peak insolation. It'll just truncate the top 4A.
One workaround if you don't want to waste this 4A would be to have two of our true solar regulators wired in parallel at the battery end, and have each panel feeding into it's own regulator.

cheers, Peter
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Follow Up By: Member - Phil G (SA) - Thursday, Feb 09, 2012 at 23:18

Thursday, Feb 09, 2012 at 23:18
"you probably were mislead by a fair amount of hype and misinformation surrounding most products in the leisure 'industry'"

Hehe, you like to put the boot into fellow Exploroz members too!

The only hype I've seen is from you today about your regulator. Haven't seen any hype about the D250S - I read the product information pdf and thought a 20A DC-DC charger which isolates the batteries and has inbuilt MPPT solar panel input was great value for $276 delivered.

I know nothing about your regulator except that you need two of them to handle Mark's panels and it doesn't isolate batteries, and doesn't provide DC-DC charging, which is why I needed the Ctek.
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Follow Up By: Battery Value Pty Ltd - Friday, Feb 10, 2012 at 00:37

Friday, Feb 10, 2012 at 00:37
Ok Phil, let's look at this unit of yours a bit closer:

Incoming solar panel voltage is limited to 22V, meaning you can't use 24V or higher rated panels with their associated efficiency gains.
It's lacking a DC/DC buck (down) converter with a wide voltage range, which is the hallmark of true MPPT solar regulators.
BTW, it has become fashionable in the solar regulator business, to call a plain PWM regulator an MPPT one. And I wouldn't be surprised if this unit can't actually track the maximum power point at all - it may be fixed to around 17V.

When both solar panel and alternator deliver power, the solar panel voltage is being dragged down to the alternator voltage, away from the panel's maximum power point. Now the unit offers the same low solar charging efficiency as a simple PWM or on/off solar regulator.
On the other hand, a dedicated true MPPT solar regulator does its job independently of any additional charging sources. It'll always track the max power point, for maximum charging amps from the panels.

Absorption/float switch over condition:
no data given
But from the D250S it can be seen that it's probably 0.4A/12hrs.
This is hard on the battery connected to it, during which any small loads also draw current, by unnecessarily prolonging the absorption stage up to 12 hours. Expect battery dry-out down the track.

Any mention of a display for Ah/Wh/A/V in/out, adjustable temperature coefficient, or different charging voltage setpoints for different battery chemistries?

cheers, Peter
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Reply By: silkwood - Friday, Feb 10, 2012 at 08:13

Friday, Feb 10, 2012 at 08:13
Why does the mention of solar or fridges always start a bunfight? Now I've purchased 240w of panels I don't think I'll need to rig up the additional 32w panel. Can anyone recommend an MPPT controller which can handle the full power of the panels (without having to rig up two controllers)?

Cheers,

Mark

ps: thanks for the recommendation Phil!
AnswerID: 477395

Follow Up By: Battery Value Pty Ltd - Friday, Feb 10, 2012 at 09:48

Friday, Feb 10, 2012 at 09:48
Hi Mark,

don't worry, there's no real 'bunfight', and on the upside, there's some good information coming out of these friendly banters.

And here's some food for thought.

Look, we're in the battery business for a number of years now.
From day one on, it became crystal clear, that the single most important factor determining a battery's life span, is the way they're being charged under less than ideal (i.e. laboratory) conditions.

Now, when a battery seller, like us, intends to build up a good reputation for their product, the last thing he would sell you is suboptimal charging gear.
So how many businesses are there, selling charging gear, but no batteries - and the other way around?

Heaps.

And how many businesses are there selling both, at a down to earth price?

One, two?

And there's a reason for this.
The charging gear seller easily blames it on the battery seller's product if something malfunctions down the track - and the other way around.

Now, from a buyer's point of view, what better way to ensure the quality of the whole system is up to scratch, by simply buying the lot from one and the same seller who actually knows his product?
This is how it works in other industries which deliver systems for more mission critical applications - the whole lot is commissioned from one supplier who starts it up and irons out the initial hiccups for the customer.

cheers, Peter

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Reply By: Member - Bucky - Friday, Feb 10, 2012 at 14:46

Friday, Feb 10, 2012 at 14:46
silkwood

Click on the link below, it may help a little

Click here Mate




AnswerID: 477427

Reply By: energy marty - Friday, Feb 10, 2012 at 15:19

Friday, Feb 10, 2012 at 15:19
Without getting in to the bun fight, the one thing I notice on the ebay sellers site is the misinformation when comparing mono & polycrstalline panels.

Theoretically, mon's should be more efficient, but in the real world, the polycrystalline are more efficient.

For independent real time feedback on what amount of power different types/brands of panels are producing, go to http://www.dkasolarcentre.com.au/ to find our what really happens with your panels out in the real world.

mh
AnswerID: 477428

Reply By: silkwood - Saturday, Feb 11, 2012 at 09:02

Saturday, Feb 11, 2012 at 09:02
Very appreciative of all the input, thanks. One more question then..

I now have a folding 240w panel set (so two 120w panels) and will soon have two 100ah or greater batteries. Either I can look at an MPPT controller which will sufficiently handle the load from these panels, in which case, still asking can anyone recommend one?

Other option- if I get two of the $100 MPPT controllers I can wire each separately to the two panels. This of course means two lots of wiring running from the panels. However if strapped together (though heavier and bulkier) this would mean less resistance loss to each controller, no? Is my reasoning correct?

Cheers,

Mark
AnswerID: 477475

Follow Up By: Mandrake - Wednesday, Feb 15, 2012 at 12:07

Wednesday, Feb 15, 2012 at 12:07
If you run two controllers to the same battery connection they will fight eachother - Each one will read the others output instead of the battery voltage and one will stop working .. Parallel connect the panels to a single controller preferably as close to the battery as you can fit it for the best results.
Cheers
Steve
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FollowupID: 753153

Follow Up By: silkwood - Wednesday, Feb 15, 2012 at 19:14

Wednesday, Feb 15, 2012 at 19:14
Thanks, Steve (not seen you post on here for a while). My problem now is I may have purchased too large a panel, as most of the reasonably priced controllers top out at 200w panels. Live and learn. If anyone knows a reasonable workaround I'd be grateful.

Cheers,

Mark
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FollowupID: 753218

Follow Up By: Mandrake - Wednesday, Feb 15, 2012 at 23:03

Wednesday, Feb 15, 2012 at 23:03
Without being too obvious here - send me an email and i can point you in the direction of a 30 Amp MPPT ... That should be good for 540 Watts of Solar ?? And it will be less than $200 !!

Cheers

Steve
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FollowupID: 753241

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