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JA Robby

Newbie

Joined: 20/07/2010
Location: Jamaica
Posts: 13

Posted: 02:30am 08 Apr 2011

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Hi all,
I have a few questions about solar pv panel,iam new to this
so please be patient with me.(1)Is it ok to start with two 10watt
12volt pv panel?.(2)Is there any truth in saying that these small
panel don't produce what they are rated at?.In other words i read
some where,where they said that these size panel cannot charge a
12volt battery.My reason for these question is iam been offered
some of these panel.So iam seeking guidance from those who have
been there and done that.

JA Robby

No man is an island.

powerednut

Senior Member

Joined: 09/12/2009
Location: Australia
Posts: 221

Posted: 04:58am 08 Apr 2011

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panels rarely produce what they are rated at. They will produce their rated output only when they hit ideal conditions. These conditions include lots of sunlight and being kept relatively cool.

The panels will charge the battery, as long as the output from the panels stays ahead of the battery discharge rate. They may just charge it slowly. If your battery is really big, you may not ever get to full charge.

To put things into perspective for you an el-cheapo car battery charger normally outputs at 12 Volts and 3amps (36Watts). your 2 panels combined will only output about 1.2amps at best. Thats enough to charge a battery, but it will take at least twice as long as the car battery charger. worse if it happens to be night time

So it comes down to it depends on what you want to do with them. If you want to run a radio or something then it'll probably be fine. if you want to keep a battery topped up then it will also probably be fine. if you want to use them to keep your house lit at night, then it wont work out well.

hope that helps.

*edit*
You can always use the panels in a bigger system later, so if they are free then great. otherwise don't pay much for them.

Edited by powerednut 2011-04-09

CraziestOzzy

Senior Member

Joined: 11/07/2008
Location: Australia
Posts: 135

Posted: 05:29am 08 Apr 2011

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if the panels are free, grab them. If you have to pay for them, don't spend too much and compare prices so you don't pay too much.
The ones you are offered will be good to trickle charge at a guess, without knowing your battery.

http://cr4.globalspec.com/member?u=25757

http://www.instructables.com/member/OzzyRoo/

JA Robby

Newbie

Joined: 20/07/2010
Location: Jamaica
Posts: 13

Posted: 02:14am 09 Apr 2011

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Hi nut/ozzy,
thank for your comments,these panels are not free but i will
think about it weather or not i should buy.My battery setups
are 2-6 volts 225ah each trojan and 18 12volts 7ah.

JA Robby

No man is an island.

VK4AYQ
Guru

Joined: 02/12/2009
Location: Australia
Posts: 2539

Posted: 07:45am 09 Apr 2011

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Hi JA

These panels would only provide a float charge under normal conditions and would be flat out maintaining that over an average year, better than nothing but thats all

All the best

Bob

Foolin Around

redbullalan

Newbie

Joined: 17/01/2011
Location: United Kingdom
Posts: 38

Posted: 11:25am 31 May 2011

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Hi
Hi im new to this as well i have built my panels 36 x 6x6 3.75 w cells the put out about 20 v 14v when connected to the batteries.
Today 4 of them in mild sun pushing 6 amps into 12 x 2 v bank of 2 and 6 x 6 v bank of 3 still finding out how well they work you have to put 30% than you use

Reddbull alan

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