Solar panels are far better now .

dragonfly1 wrote:

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Get on to Bitdeals on eBay German panels 200 watt $179 we have had them on our motorhome for eight years and no trouble and they are good to deal with 

Dragonfly1

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 Agree Bitdeals do have good panels however there not 100% German.  I believe the cells are German and the panels are manufactured (assembled) in China to specifications of Rich Solar which is an Australian Company. 

I've bought close to 15 panels from them over the last 6 or so years and installed them for myself and family/friends, I've never had any issues with their panels. With Solar Controllers however I do reccomend doing some research and buying a better known brand as I've seen a few of these fail.

Hi

Not counting the panels on my house I have bought 11 panels and 4 tiny battery top up ones from ebay mostly or Gumtree, and all cheapest or close to it on price with delivery included, from good sellers in Australia. I have checked them in the backyard under load with amp and voltage meters and ALL HAVE BEEN UP TO SPEC. All worked OK till I sold the camper or till today if I still have them. Even the tiny ones at about $30 for 4 of them. So much for the crap about you only get what you pay for 

 But feel free to pay twice or three times as much at the retailer of your choice if it makes you feel better.  I would choose to put twice or three times the number of panels on ! As I have put different leads on them all, IE heavier cables, I am not so worried about that part and the regulator should be at the battery anyway to work well. 

Cheers jaahn 

-- Edited by Jaahn on Saturday 7th of January 2017 09:14:18 PM

Kyocera is a Japanese company but the panels are made in Korea, some brands are made in the US but not RV suitable panels as they specialise in the more high tech stuff, the rest are made in China no matter what the company selling them claims.
If you are buying for the advertised life time warranty then buy from a company that has a well known name so there is a chance they will still be there if you need to make a claim. The alternative is to buy panels at half or even 1/4 the price and if they fail then just replace them.
A different way to look at the equation, if the panel cost $1 watt and lasts for 5 yrs and another brand cost $4 watt and lasts for 20 yrs which was cheaper? The $1 watt panel as the technology is improving so fast that the panel you paid $1 watt for 5 yrs ago will be 50 cents a watt, or $1 watt will buy a much better panel as far as output to panel area goes.
Just watch the Vmp is 17v to 18v @c25*C for a lead acid 12v battery, 16v is ok for lithium batteries but too low for lead acid of any type (flooded cell, AGM, Gel, Lead Crystal) 12v is no use for anything much and they are out there :lol: Remember I is the Vmp not the Voc you are looking for, there is no output (amps) when the panel reaches the Voc (open circuit voltage)

T1 Terry

macka17 wrote:

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3 Kyocera Terry.
2 on Caravan (Offf roader,) One on Prev Yacht.

That one 20ish. Still bouncing round on transom frame,
somewhere near Fiji last I heard.with a Bosch German.

Van ones are around 14 now.

You MAY save a few dollars over time with cheaper ones.
But, equal total outputs over that period of time??. hmmm.
And the hassles of replacing on roof or van or boat .
How many times.

Don't think so. Unless you really tight.

I just buried a 40w BP panel.
20 yrs on boat 14ish on carport.
Still giving 2.2 till one side dropped out. (It's mate still ticking over so far)

AVERAGE 12v panels give around 21v. reduced to 17ish through reg.
14ish at battery ends.

I think I'd stick with the more reliability and more output for my dollars thank you.
With a lot less hassles.

Basically a "take your pick".
A bit like false economy.

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 Not actually how it works Macka17, the solar panel open circuit voltage is 20v to 21v on average, but no amps available at that point, max amps available at around 17v @ 25*C but as the panel gets hotter (not the ambient temp but panel internal temp) that 17v reduces by 0.4% per degree above 25*C. Internal panel temp can exceed 70*C and in full sun and doesn't stand a snowballs chance in hell of remaining at 25*C so the 17volts Vmp is just a test figure from a lightbox, not the figure they run at out in the real world. With a PWM type controller the solar voltage close enough matches the battery voltage until the battery reaches the preset voltage inside the controller, that is when the controller starts to limit the voltage by limiting how much current it lets through to the battery. This is achieved by rapidly turning the link between the solar and the battery on/off/on, the longer the off part of the cycle the less current (amps) flow through to the battery and as a result the battery voltage remains at or below the controllers preset target voltage.

 

As far as quality and life span, I have 10 x 70w Solarex (pre BP solar days) that date back to the '60's and still have 85% of their output, but the area they take up compared to $1w Ebay panels is less than 50% efficiency/output per mtr sq) and that is the real difference. I don't have the area available on top of my motorhome to waste, I can fit enough $1w solar to deliver a fairly constant 700w during the peak sun hrs, the same area using the old Solarex panels would give me less than 350w. They have lasted well but technology has left them behind, so is it really a good value judgement to buy expensive panels?

 

T1 Terry

Hi Macka,
The wiring has the most to do with panel effectiveness and very few "professional" installers seem to be able to get it right. When the factories start producing 250w 12v nom. panels and fit 4mm sq solar cable you just have to shake your head and wonder who designs this stuff. Then you see a roof full of 12v panels connected in parallel using the 2 into 1 couplers between each panel to a single 5 mtr run of 4mm solar cable and you wonder which Corn Flakes packet they get their qualification tickets from cause they obviously don't have a clue.
Helped wire up an off grid house that already had 1.6kW of solar and the owner had just installed another 1.6Kw. When I pulled out the 6 B&S cable he looked a bit stunned, when I said we needed at least 2 runs it was all to much for him. He pointed out the solar install peoples run of 4mm sq solar cable running from each 800w group and told me they didn't get hot so that was plenty heavy enough. I ran one run of 6 B&S cable and in the winter sun the cable got that hot it was hard to hold, so he relented and allowed the second cable run. He has since fitted a split system air con so the solar now works a lot harder and the 2 runs of 6 B&S are now getting hot, yet the 4 mm solar cable isn't....... because most of the current can't get out of the panel

T1 Terry

macka17 wrote:

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You must have different installers down there, or diff, State reg's?

I checked mine. next door and daughters roof systems going up.

Don't know those measurement figures you lot use
but it was all Dual core\double sheathed.
and EACH copper core thickness "dia,) is 7 or 8mm with Vernier.

Reasonably heavy stuff for 4 and 5 KVA systems. I thought.

I have a 6 mtr offcut he gave me to use on 200w panel I got for this van
(One of these day)

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All cable is rated by the cross sectional area of the conductor as the actual cable diameter varies with the thickness and number of layers of insulation. 7mm or 8mm copper conductor would mean it was either 1AWG gauge or 1/0AWG gauge, 42.5mmsq or 53.5mmsq section, that is battery starter cable size, huge for solar use and no idea how it would be joined at the panel.

Are the roof systems you mentioned series or parallel connected? Back to battery or grid tie?

 

T1 Terry