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asvin bahadur

Newbie

Joined: 29/07/2008
Location: Mauritius
Posts: 21

Posted: 05:18am 26 Sep 2008

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Hi,

i have a question and i am sure someone out there will be able to help.

i have purchased 3 solar panels (so far) of 10w 12v each. i want to increase the watts and keep the 12v and charge a 12v battery. i am thinking that i should connect the solar panels in parallel. will that work?

thank you.

asvin.b

AMUN-RA

Senior Member

Joined: 10/03/2007
Location: Australia
Posts: 144

Posted: 09:05am 26 Sep 2008

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yep but hope its only a small battery and you have lots of time and sunshine Mick

Every day the sun shines
& gravity sucks= free energy.

wind-pirate

Senior Member

Joined: 01/02/2007
Location: Canada
Posts: 101

Posted: 02:24am 29 Sep 2008

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3 x 10 watt pannels = 30 watts about 2 amps. "Max"

That will charge a 12 volt battery in about a week.

I use a setup like this to keep the batteriess of my farm equipment charged in the winter months. I have as many as 6 in the bank. I use a charge controller, so they don't over charge. There is no load on them at any time. After about 2 weeks the green light is on and they stay like that till spring.

Ron

THE Pirate.
stealing wind & solar energy is fun

asvin bahadur

Newbie

Joined: 29/07/2008
Location: Mauritius
Posts: 21

Posted: 05:05am 29 Sep 2008

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Dear Ron,

Thanks for the information. do you have a formula to calculate the amps?

The battery i am using is a 12 VDC and is about 24 amps. yes that would take a long time to charge.

but you see, my plan is that eventually i will end up purchasing at least 7 more panels (10w 12v) which will give me around 100 watts. as you know, the price of solar panel is so high and it is not available locally. so i am having to purchase them on eBay (cost price + shipping). if i buy them in small quantity and over a period of time, financially it is best for me.
if i do eventually purchase a 40 watts solar panel or higher, i will have to pay custom duty here to get the product since the price will be higher.

thanks

asvin.b

wind-pirate

Senior Member

Joined: 01/02/2007
Location: Canada
Posts: 101

Posted: 04:08am 01 Oct 2008

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Hi Asvin

It seems that here in Canada, A 15 watt solar panel is "Rated" At 1 amp. This one amp is not seen very often. In Winter (cold weather) they seem to work the best. That is when they will reach there maxium. Make sure that you leave a air space behind the panels when you mount them at least 1" (25 to 30 mm). if you are in a very hot area you should allow more, Double that. A dark roof is the worst. It collects more heat and less light. I find A white/light back round works the best, and they run cooler. Keep them facing the sun through out the day is the biggest part too...

Ron

THE Pirate.
stealing wind & solar energy is fun

AMUN-RA

Senior Member

Joined: 10/03/2007
Location: Australia
Posts: 144

Posted: 07:31am 03 Oct 2008

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Asvin there should be info on the back of the panel showing the max amps and volage .A 10 amp panel about .59 amps in full sun in the middle of the day.for your location
15-25 degrees facing north to the equator you would get about5-6 peak sun hours per day call it .5*6=3amp hours per day with no loads 4 days would charge it.

Every day the sun shines
& gravity sucks= free energy.

asvin bahadur

Newbie

Joined: 29/07/2008
Location: Mauritius
Posts: 21

Posted: 04:33am 01 Nov 2008

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hi there,

i am having a problem with my connections and i'm not sure what it is. i am sure that someone out there might help.

well to start with i will describe the situation.

as mentioned before i have connected my three solar panels in parallel and connected it to my charge controller.

then i connected two small batteries of 12v 3amps in parallel and connect it to the charge controller. the batteries are new and are fully charged.

electrical wires (possitive and negative)were connected to the load of the charge controller. this wire is more than 15 meters long and it goes downstair where it is connected to my 300 watts 12v power inverter.

here is the problem - when i connect a table lamp of 15 watts to the power inverter, the latter does not light up. infact it keep on flashing. the DC volt coming in is now 13.85v.

i am doing something wrong and i dont know what it is.

just to tell that in the past, i have used one of the two 12v battery to light the AC lamps through the inverter and it worked just fine that is without going through the charge controller.

i have purchase two more solar panels (10w12v) but have not received it yet. will connect them to my existing panels later on.

please advise.

many thanks

asvin.b

AMUN-RA

Senior Member

Joined: 10/03/2007
Location: Australia
Posts: 144

Posted: 08:27am 01 Nov 2008

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For 12 v shorten the wire run or double the wire then get rid of the inverter and buy some 12v led from ebay
for your needs the inverter is a loss you can't afford
and dont need. with your small batteries and panels leds are the way to go cheap to buy and run and last a long time, hope this helps Mick.

Every day the sun shines
& gravity sucks= free energy.

asvin bahadur

Newbie

Joined: 29/07/2008
Location: Mauritius
Posts: 21

Posted: 07:34am 16 Nov 2008

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hi,

i just want to update you guys on m progress. The problem i mentioned earlier, well i manage to solve it and now it is working just fine. the only problem is where to use this power!!!

anyway, my problem was that the wire connecting the solar panels to the charge controller and battery was short since these connections were made near the solar panels (on the roof).

from the charge controller to the inverter there was around 15 meters (inside the house). it was way too long and for some reasons, the DV current was not constance and that why when it was connected to the power inverter and to a lamp (AC), it flicked and beeped.

therefore, i changed the position of the charge controller and batteries. i have moved them inside in my house with my power inverter and bingo, it work. th solar panels are connected by the 15 meters wires to the charge controller, batteries and charge inverter. i am using it to power a 15 watts lamp in my TV room. i guess i can use it to power a few more applicants.

asvin.b

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