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Old 25-02-2015, 09:05   #1
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Chinese Knock Off Solar Panels

Here is an excellent article about comparing the real deal Solbian with genuine SunPower Cells vs the Chinese knock offs. Must read for anyone considering going this route if you want to make an informed decision.

Essentially there are a lot of panels that look like the SunPower Cells but they are not all made with the same quality controls and they don't handle the bending as well. Articles like this is why we struggle with the decision to go with a lesser brand vs. the Solbians. In the end we went with Renogy semi-flex panels ordered from Amazon that were Prime eligible for free shipping. We paid $197 each for two 100 watt panels. More panels will be added in the future but these are the two to go on the bimini.

One thing my research pointed to was that testing the panel once you get them is imperative to getting good performance out of the array. On line I have read reports of people ordering two panels and getting one in excellent shape while the other had oxidation and damage. Others had received panels that looked the same but performed very different. So I did a thorough inspection of the panels when I got them. One thing I noticed right off the bat was that the connection on the Renogy panels, compared to the Solbians I had seen at the boat shows, were a little underwhelming. The Solbians have a nice junction box but the Renogy had a cheaper plastic connection filled with sealant to make it waterproof. I like the Solbian approach better but you get what you pay for.



After I was satisfied with the initial inspection, I moved on to testing the performance. It took a couple of weeks to finally get decent enough weather to do the test. It was cold and very sunny when I set up the panels for testing. Using a saw horse I angled the panels towards the sun and ran a couple of tests. The open voltage readings (multimeter connected directly to the MC4 connectors for the panels) on the panels were 23.4 and 23.5 volts. Next I hooked them up to a Group 27 AGM battery we had for work. The battery had been depleted to roughly 50% state of charge. The negative lead for each panel was connected directly to the negative battery post. The positive leads went to a cheap "A/B" style switch I had for work stuff. The common side of the switch was connected to a multimeter positive lead and the negative lead was connected to the battery post. A second multimeter was connected to the battery to get voltage readings. This setup allowed me toggle between each panel and see if they were performing the same. (Sorry, its unlike me but I forgot to photo the setup.) For both panels I was getting 16.2 volts at the batter with a current of 6.3 amps. I let each panel run to the battery for about 15 minutes before recording the reading.

These results put my readings slightly above the I-V Curve published by Renogy. I wasn't too surprised to out perform their curve because it was only 20 degrees F when I was doing the test. The published curve is for 77 degrees F. And since heat reduces the efficiency of the panels I expected to be on the high range of the curve, being just outside the curve gives me some hope to get close to the curve in a real world application.

Next step will be to mount the panels to the bimini and wire them up with the charge controller. Unfortunately that will have to wait another month or two. My Bride has been working to replace the window in the bimini that broke last year. That is complete and she has repaired some other areas as well. But we can't put the bimini up to check the panel placement until we take down our winter biodome (aka clear shrink wrap). In the mean time I can work on installing the charge controller (I was able to get one of the last Rogue MPT-3048 charge controllers available thanks to Compass Marine) and getting the rest of the install ready.

In the meantime, onto to other projects on the Epic To-Do List. This weekend I will be changing the macerator pump. That will be a shitty job (pun intended).
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Old 26-02-2015, 20:58   #2
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Re: Chinese Knock Off Solar Panels

I put a pair of Renogy 100ish W panels on Voyageur mid-summer, before a cruise. On sunny days, we drew essentially 0 from the house batteries when underway. In September, the Xantrex inverter/charger developed a ground fault and would no longer work without tripping the boat's master breaker, so I simply disconnected it and relied on the solar panels to keep the batteries charged when we were off the boat. Again, no problem. I have Renogy's MPPT charge controller, but I'm not convinced that it implements the charge function properly for the quartet of AGM house batteries. It seems to "reset" to maximum charge rate every time the sun comes up, regardless of battery state. It's all dismantled for winter storage, so it will be another 2ish months until I can investigate further.

My panels were temporarily rigged atop the bimini, with cord holding them in place. A new bimini, with holes to facilitate the attachment of aluminum mounting bars to the bows, to support the panels, will be delivered this spring.
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Old 01-03-2015, 19:25   #3
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Re: Chinese Knock Off Solar Panels

Just purchased the 100w renogy starter kit from Amazon. Hard panel rather than flexible, and I understand the controller is trash, but I'll update with my experience.


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Old 01-03-2015, 19:49   #4
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Re: Chinese Knock Off Solar Panels

Quote:
Originally Posted by brownoarsman View Post
Just purchased the 100w renogy starter kit from Amazon. Hard panel rather than flexible, and I understand the controller is trash, but I'll update with my experience.
Same kit I have on mine, and used all summer with zero issues, multiple weekend trips with plotter, VHF, lights, charging my phone, and also using a 24" LED TV to stream Netflix from time to time. No issues from me (each experience will differ of course - I just sail around a lake, I'm not out in the big stuff)
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Old 01-03-2015, 20:16   #5
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Re: Chinese Knock Off Solar Panels

Good to hear Charlz! I'm in a similar situation: only electric loads are phone, laptop, tiller pilot, and cabin/running lights. I really only need 60w, but can't find a panel that small on Amazon, and I don't like using eBay!


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Old 01-03-2015, 20:22   #6
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Re: Chinese Knock Off Solar Panels

I'm not convinced by the Solbian propaganda. They compare a broken cheap panel to a hand picked panel of theirs. You'd need an independent company to randomly select at least 10 panels from both the cheap and the solbian stock, and then compare them.

We use Renogy panels and have no complaints so far!
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Old 01-03-2015, 21:37   #7
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Re: Chinese Knock Off Solar Panels

Going back to Monte’s issues:
Put that power hog on a diet and trim consumption underway to less than 200 amp hrs/day
a. Replace all incandescent with LED’s—especially tricolor and cabin halogens
b. Replace 3 amp laptop with 1 amp netbook for AIS/Charts/Communications/entertainment
c. Turn off cockpit refrigerator
d. Turn off chartplotters on open ocean passages
e. Minimize radar use
f. Buy every piece of equipment with an eye on power consumption—for example VHF standby draw can range from 0.2 to over 0.5 amps.
Recognize that for every amp-hr you draw out of the batteries you need to put back 1.2 amp hours
a. Only run the water maker when the engine is going.
Maintenance free lead acid batteries are the absolute worst for boats—set your regulators to regular lead acid(14.4v) and throw the maintenance free batteries away if they can’t take it
Internal and temperature regulated alternators are the worst for sailboats. However, you have enough solar to keep a normal boat charged unless you have several cloudy days in a row.
Understand how batteries charge and discharge. If you are drawing 10 amps and your voltage drops below 12.0, they are getting too low and it’s time to add another charging source. If you are at 14.3 volts and your batteries are only taking 20 amps of charge, they are near full, and it’s time to turn off the engine, no matter what the battery monitor says. If the batteries are charging at 13.4 volts and 10 amps, they are usually a long way from full.
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Old 02-03-2015, 10:58   #8
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Re: Chinese Knock Off Solar Panels

Charlz-how did you mount yours and what hardware did you need outside of what was in the packet? My pushpit is pretty narrow, so I would need to offset them out of the way of the ladder and probably have a side support; or put them on the coach roof; in which case I'll probably have to clamber over them on passage. Bimini mount is a no go as are davits.


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