What solar panel should I buy?

[nb celestine]

I,ve looked in the search facility and I,m still none the wiser. What I think I,m looking for is a 150 watt panel and a controller that shows whats going in; not a traffic light thing.

I only have a 12v telly and a led light on at night and the odd pump going off now and again, so I don't use a lot. Don't use the laptop during the day and only charge when the engines running.

The idea I get is I should get one for about a £1 a watt but I cant find one. I should have said the tv uses about 1.8amps and the led light about 0.1 of an amp.

The batteries are 2 year old liveaboard and are in average condition. I,m just looking for something to keep the batteries topped up rather than power any equipment.

 

[smileypete]

For the 18V camping/RV type panels try a search on Ebay UK for '80W solar panel' then rank by best match, should show up a few, though £1/watt is a little out of reach, eg:

 

http://www.ebay.co.uk/itm/Brand-New-Perlight-Mono-All-Black-Solar-Panels-20w-40w-60w-80w-100w-120w-12v-/150955494600

http://www.ebay.co.uk/itm/Biard-80W-Watts-Monocrystalline-Solar-PV-Panel-12v-24v-Battery-Charging-80-W-MCS-/380628053198

 

For PWM controllers that will suit the above OK, these have a decent spec and are worth a look, made by the same company as the Tracer MPPTs

 

http://www.ebay.co.uk/itm/10A-12-24v-EP-Solar-LS1024-Solar-Charge-Controller-/281098009028

http://www.amazon.co.uk/SainSonic-Waterproof-LS1024RP-Controller-Regulator/dp/B008RJEVEM

 

(Bit cheaper from seller based in Asia...)

 

http://www.aliexpress.com/store/product/10A-LS1024RP-EP-PWM-LandStar-Solar-light-Controller-Waterproof-With-Timer-light-sensor/319525_550121659.html

http://www.aliexpress.com/store/product/10A-LS1024-EP-PWM-LandStar-Solar-Charge-Controller-Regulators/319525_550091095.html

 

A 10A PWM should just about be OK with 160W of 18V panels, but a 80W panel might be enough for your needs.

 

To see what's going into the batts, an inexpensive way of doing it is to feed the controller or the panels though a wattmeter/power analyzer:

 

http://www.ebay.co.uk/itm/New-Digital-60V-100A-Battery-Balance-LCD-Voltage-Power-Analyzer-Watt-Meter-/171014142730

 

The same Asia based seller as above also does PWM controllers that use the same meter as the Tracer MPPT:

 

http://www.aliexpress.com/store/group/RV-Remote-Solar-Controller/319525_211600456.html

 

Don't forget a fuse in the positive at the batt end to protect the wiring between batts and controller.

 

cheers, Pete.

~smpt~

Edited May 15, 2013 by smileypete

[eightpot]

http://www.bimblesolar.com/offgrid/12v

 

I bought one of these with the 20amp MPPT controller. Very pleased.

[smileypete]

Just remembered that Navitron do a domestic type panel that have a lower voltage/power output than the usual domestic ones:

 

http://www.navitron.org.uk/product_detail.php?proID=469&catID=140

 

The only drawback being it's wider than the usual camping/RV type ones and would need an MPPT to get the best output from it.

 

Even so, if budget is tite it'd still give a decent output with the £20 PWM mentioned above, this being because it has a lower voltage output of 23V than the usual domestic type ones.

 

With PWM it'd only perform as well as a 135W 18V panel but £120 for equialent 135W of solar is still better value than the 80W 18V ones which are pushing above £1/watt these days, and it might do for the OPs needs.

 

cheers, Pete.

~smpt~

Edited May 16, 2013 by smileypete

[nb celestine]

Thanks for the advice people. Just what I was after.

[lesrollins]

Just looking on the bimble solar website and thought they were well priced. Until you read about the 170w mono crystaline panels it states that they have had 2 years use and come with no guarantee so are they still a bargain or best avoided ? .

[eightpot]

They are second hand. On a similar thread on here I posted a link to a message board thread where the bimble panels were discussed. It turns out they were fitted in an application in Australia and then removed under warranty by the manufacturer due to a defect in construction. The backing plastic has yellowed due to the wrong additive being added which would have had issues under strong sunlight in their original location, but since I'm in a more temperate latitude I don't consider it a problem. The solar cells themselves do not have any latent faults.

 

I took a chance on a panel as I considered it had been soak tested for an extended period prior to me buying it. So far, so good.

[smileypete]

One thing about the Bimble panels is the P&P is relatively high, so the price of 1 panel plus shipping might be close to a new panel from elsewhere. But if collecting or buying a few panels it's not such a problem.

 

cheers, Pete.

~smpt~

[lesrollins]

So who are doing the best prices on 12v panels at the moment probably looking at 140w panels. And what size mppt controller would I need for a 140w panel. Thanks

Edited May 19, 2013 by lesrollins

[smileypete]

So who are doing the best prices on 12v panels at the moment probably looking at 140w panels. And what size mppt controller would I need for a 140w panel. Thanks

 

For 12V panels the 80W size seems to give the cheapest £/watt, for a small amount of 12V panels like 160W a PWM will probably work out cheaper, see the links in post #2

 

That said Navitron do a smaller sized domestic panel that even when used with PWM will work out a bit cheaper than the normal 12V ones, see post #4. With 20A Tracer MPPT it'll give a fair bit more output.

 

cheers, Pete.

~smpt~