Sam's Club Solar Set-Up

[Mwilliamshs]

So Sam's Club has these kitsI was looking at. $649.00 locally. They're "Grape Solar" kits but just component kits assembled of Xantrex stuff and somebody's panels, I don't think Grape Solar makes anything. No, they're not the best of everything. No, they're not smokin' hot deals $690 @ Amazon tho... so maybe $640 is not too shabby. Yeah, they're interesting and reasonably priced. They come with 2 panels, 100W each and a Modified-Sine Wave inverter, the Xantrex Xpower 450, a solar charge controller, the Xantrex C35, and cables. Looks like MC4 connectors and some battery leads but I might be wrong on that part, just looking at pics.


2 each of 100W Polycrystaline Panels @ Grape Solar (not priced @ Grape Solar's site)
18.0 V @ 5.56A (MPPV @ MPPC)
13.88% Efficient

Xantrex C35 @ Grape Solar ($129.99)
Xantrex C35 Spec Sheet (pdf)

Xantrex Xpower 450 Inverter
Continuous AC Rating: 360 Watts
5 minutes max rating: 450w
MAXIMUm surge rating: 700w
Modified Sine Wave
Xantrex Xpower 450 @ Grape Solar ($99.99)
Xantrex Xpower 450 Spec Sheet (pdf)

So if you go by Grape Solar's prices on their site, $130 for the Charge Controller and $100 for the Inverter means the panels and cables make up $420 of the kit price ($650). Call the cables $20 and the panels $200 each. That's not TOO bad, right? I know $1/w is supposedly the going rate but I think it's gone. I checked the specs on the Charge Controller and it can actually handle 1 extra panel, like if you bought the kit @ Sam's and another panel separately from Grape Solar or $149.99 @ Amazon, with 1 Volt of Max Power rating to spare and let's face it, no panel is gonna be at MPPV much if ever...plus there's always this kit which is 300 watts of the same panels and a 2000 watt pure-sine inverter plus the same C35 controller on Amazon for $1,299.99. At previously mentioned prices ($150 for the extra panel) that means going from 200w and modified-sine wave to 300w and pure-sine costs $650...or the same as another kit (could have 400w of solar and 2 modified-sine inverters for the same money). Is the 2000w pure sine inverter worth the $500 difference? Guess not, $355 @ Amazon.

The real reason I was shopping at Sam's though was these batteries. Energizer Premium GC2 6v Deep Cycles for $112.68 each, locally. 48.5 cents per AH.

My thoughts are if I bought two of the batteries, the 200w kit, and some 25' 2 gauge jumper cables (cut the ends off, use to wire batteries), plus fuses and what-not, I could have a pretty darn decent, easy, solar set-up for right at $1000 bucks all purchased locally and from a store that's fairly good about returns, etc.

Thoughts on the C35 controller? Anybody know if it's able to charge @ 14.8v and/or @ what amps? Not looking for a PWM vs MPPT debate just opinions of the C35 specifically. I know the Inverter isn't pure sine wave but the only thing I'll have in the van that cares is a laptop (dc-dc charger is my preference, this is a back-up) and it can have it's own smaller inverter (might be handy if I get a nice camera too) so the big one can be turned-off when I'm just using the computer (or camera) and it'll save me the expense of a Pure-Sine Wave Inverter big enough for everything else (which ain't much, as far as AC goes). Thoughts on the Xpower 450 Inverter itself? Again, not looking for Pure vs Modified sine-wave discussions, just this particular inverter's good and bad. Any thoughts on the panels themselves? THAT I'm all on ears on!

 

[dwh]

Your link to the C35 spec sheet isn't. It's actually a link to the X450 spec sheet.

Here's a link to the C35 manual:

http://pdf.wholesalesolar.com/controller pdf folder/XantrexCSeriesManual.pdf

According to the manual (page 22) it has potentiometers to adjust voltage set points.

Page 42 describes how to adjust the voltage set points. Bulk charge can be set anywhere between 13.0v and 15.0v. Float is between 12.5v and 14.5v. Don't see anything offhand about adjusting Absorb voltage.


The X450 should be just fine. I don't think Xantrex makes any crap. The only issue I see with it, is that it can possibly draw up to 20a on the 12v side, and that might be too much for some cig lighters' fuses.

 

[dwh]

As for the panels - they're 36 cell polycrystalline. Should be pretty easy to find comparisons.

You say they are 13.88% efficient, but the page you linked to says 16.8%.

 

[dwh]

Oops, forgot this...

and let's face it, no panel is gonna be at MPPV much if ever..

Never with PWM.

The Maximum Power Point is probably going to be somewhere between 16v and 18v, and without an MPPT controller, the PV voltage will be at whatever the battery voltage is - and that won't ever rise above the bulk stage voltage set point.

 

[Mwilliamshs]

Link fixed. I had too many tabs open at once and did too many edits too late at night I guess. :snorkel: The efficiency says "approx. 16.8" in one place close to the top of that page but under Electical Specifications it says "13.88". Scroll down and you'll find it. The "approx. 16.8" seems more like a theoretical or mathematically derived # where as the "13.88" seems more likely to have been measured considering it's not listed as an approximation and the greater significant digits but really who knows how accurate either number is on any one panel. I just picked the lesser value to improve likely realism. Small differences either way. Yeah the pmw won't hit mppv ever, kinda my point. I've compared lots of panels online but would like to find someone who's used these specific panels.