I have asked about solar in the past and never have done anything with it. I was just reading on the truck camper forum and somebody mention this panel.Deal on Competition Solar panerThis looks like a pretty good price to get started and figure I could mount 3 of these on my roof and have a decent amount of solar to get started. I realize the controller is probably not great, but figure I could always upgrade later. Is it ok to have 3 or 4 separate controllers? I would be feeding 4-6 volt batteries.For all of you who know a lot more than me about solar is this a decent setup to get started, especially the panel or am I wasting my money and should I wait and get something better.There is also a little more details of this same set up on the home depot website at the following link.ClickyI am in no way associated with any of these retailers or the product, I am just wondering if this is a good relatively cheap way to get started with solar.Thanks for your input.

145w with a controller and shipping for $125. Can't beat that with a stick.I'd like to see more on the panel specs and about the controller. Then again if the controller is junk, you can replace it for very little with a known unit.

Well, not to say that I'm the one "who knows a lot" about solar, but hopefully enough to answer some.1) I am just wondering if this is a good relatively cheap way to get started with solar? Yes. $125 for 140W panel with free S/H is a good price even if it were a panel alone. Consider that you're buying just a panel. Amazon has never been a good source for panels or controllers. Description like "... blocking diode and a bypass" is funny. What "bypass"? Like a highway around big city :)? I would guess that our not-so-learned Chinese friends meant "bypass diode", but then the question is - how many? Let people who really know "a lot" about solar, analyze this cryptic text and make educated guesses. I prefer buying good panels from reputable brands. With known number of diodes and good frame. There exist good Chinese domestic brands, if you're on a budget.2) Is it ok to have 3 or 4 separate controllers?No. Besides, what you're getting here is a cr-ap of controller, so getting 4 of them will 4 times increase the chances that system will cr-ap out when you expect this the least. If you buy 3 of those, throw controllers out and get a single 30A controller of PWM type. If you buy 4 - then get 40 or 45A controller. The wiring is easier with one controller, this is reason big enough for me.3) This looks like a pretty good price to get started and figure I could mount 3 of these on my roof and have a decent amount of solar to get started?Yes, good price for 140W panel. If you get 3 - then get a proper 30A controller.Consider the panel size. Make a template of that size and see if 3 of them fit on the roof and there is at least 8"-10" to air conditioner and/or vent lid, so they won't shade the panels. Here is a popular source for panels: Solarblvd. Their 140W panels are square, 3*3 ft, this may or may not work better than those panels from Amazon.Don't want to pour too much info onto your head at once, but with 420W roof-mounted solar array people usually go for 2*200 or 2*250W panels. Those are roughly 3*5 ft and weigh 40 lbs each, no matter if it's 200 or 250W, same size and same weight. The biggest difference from your planned panels is that they have a higher nominal voltage - 24V - so they require a different type of controller, it's called MPPT and costs more than PWM. With 420W array made of 24V panels I would buy Rogue 3048 controller. There are cheaper 30A MPPT, but there isn't anything better. Not to say that you HAVE to have 420W made of 24V panels and MPPT. You may as well have 420W made of 3* 12V panels like the one from Amazon, and PWM controller.

The price is sure right. I'd guess I'd want to know what the static load rating for the module is, most good modules have a 5000+ Kpa rating.

If the size works I would call that a good deal. Multiple controllers is fine.Started? Probably call it done.

Like lieutenant Colombo used to say, "... and one more thing" ;) :I don't see magic words "UV cable" and/or "MC4 connector" in description. But I do see a ghastly pigtail like those on cheap 5W solar chargers, with a male-female low-voltage connector on unknown gauge cable, and crocodiles. I had connector and crocodiles like these on my car solar maintainer. Corroded like hell in a month. I'm afraid that you'll get what you pay for, - solar panel that is not designed to be exposed to sun and elements.Maybe I'm wrong, and ugly pigtail can be easily disconnected at the junction box and/or replaced, and the cable is not terribly bad, and the frame is half-decent and the J-box is somewhat weather-proof. Go to Home Depot and have a closer look.I'm picky about my solar components because consider it a long-term investment. Want it to work, and work reliably.

Competition Solar 145 watt with controller for $125

15 Replies

pnichols
Explorer II
Oct 27, 2014
Apparently I waited to long again! Price is back up to $399.

Huuuuuuh .... what's up with that??

$399.99 is a long way from $125.

$399.99 is way too much for 145 watts and $125 is way too little.

There is something Rotten in Denmark going on here!!!
Katman1100
Explorer
Oct 27, 2014
Apparently I waited to long again! Price is back up to $399. Thanks for the info I will look at some of the links you guys provided.
All things being equal it sounds like I am better with a poly panel vs Molly? Is this correct?
If I am willing to get a mppt controller more volts is better if the same size watt panel?
Thanks
Almot
Explorer III
Oct 25, 2014
jrnymn7 wrote:
I don't recall anyone mentioning mono vs. poly. Apparently, poly handle cloudy conditions better, while mono handle partial shade (i.e; some obstruction) better? May be something to consider.

Poly is better under cloudy conditions. The panel in question is mono. How well it handles partial shade, i.e. when part of the panel shaded by tree branch, depends on how much shade and how many bypass diodes, and they don't tell how many.

There are no benefits in using multiple PWM controllers vs single controller, and quite a bit of trouble with wiring from the roof to all those controllers, and from controllers to battery.

A good 35A-40A PWM with remote temp sensor and all adjustments will cost around $100-140. A half-decent one will cost $30-50.
jrnymn7
Explorer
Oct 25, 2014
I don't recall anyone mentioning mono vs. poly. Apparently, poly handle cloudy conditions better, while mono handle partial shade (i.e; some obstruction) better? May be something to consider.
Tom_M1
Explorer
Oct 25, 2014
The connectors I used are the SB series which do not separate.

The SB style are available in different colors. Each color is keyed differently so you must use the same color.

The the other style is the PP series.

I purchased some connectors at PowerWerx.

I also bought some on eBay.
westend
Explorer
Oct 25, 2014
Snowman9000 wrote:
Tom_M, (bit of a thread jack already) how hard is it to pull apart the two halves of those particular Anderson connectors? The reason I ask is, I have a set of the 75 amp Power Pole connectors, the regular square edged ones with no grip section (unlike what yours have), and they are very stout to pull apart. So much so that I decided not to use them on something where I would need to pull them apart with any regularity.
Wax.
FWIW, a lot of guys in my area have the larger ones for snow plows. I've seen them doused with WD-40 and all other manners of lube oils but wax isn't a mess and affords a smooth surface, easier to pull apart.
Snowman9000
Explorer
Oct 25, 2014
Tom_M, (bit of a thread jack already) how hard is it to pull apart the two halves of those particular Anderson connectors? The reason I ask is, I have a set of the 75 amp Power Pole connectors, the regular square edged ones with no grip section (unlike what yours have), and they are very stout to pull apart. So much so that I decided not to use them on something where I would need to pull them apart with any regularity.
Snowman9000
Explorer
Oct 25, 2014
I would say the ugly pigtail thing attaches to the output side of the charge controller. We really don't know what the panel's junction box looks like, what wires it has, etc. It "probably" has the standard black weather-resistant j-box on it, and may or may not have MC4 wires attached. If not, simply buy an MC4 6 foot "extension cable". Cut it in half and connect it to the j-box. Voila, you have a pair of male and female MC 4 wires on your panel. At unlimited-solar.com, such a 6' in 12 ga costs $3.99, while 10 ga. costs $4.99.
Tom_M1
Explorer
Oct 25, 2014
The price is great and there would be no problem connecting up multiple controllers. You can always upgrade to a better controller later. I noticed on Amazon that it states "Usually ships within 3 to 5 weeks". Sounds like it might be shipping from China.

As for wiring, I replaced the standard MC4 connectors with Anderson Power Pole connectors and used 10 gauge wire.
Golden_HVAC
Explorer
Oct 25, 2014
Hi,

You can buy a controller rated at 20 amps for about $13 at this place. AliExpress.com

You can buy 100 watt 12 volt nominal panels for close to $1 per rated watt. Check this place too. SunElec.com

Good luck!

Fred.