A solar panel (1 Viewer)

Nov 30, 2009
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Not good.

If you glue it down and the roof or the panel needs service what do you do ?

A sharp blade , slid under the brackets got our solar panel off the caravan roof before we sold it to buy the motorhome. Then a bit of solvent /thinners got off the residue sikaflex .
Ralph then re stuck it on the Motorhome.

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chrisgreen

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Jul 26, 2009
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It means that, as is quite normal on a forum, someone gives inaccurate or partial advice.

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im saying that if it was pointing at the stongest brightest sun it would produce 3.41 ah so over a 10 hour day 34.1 ah.
on a dull day 1/2 ah.???
p/v solar is a better option per watt:thumb:
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Shall I put this right....

The panel will output 3.41A. No h.
3.41A over 10h is 34.1Ah - this meaningless.
p/v is better..... They are all photo-voltaic - latin - photo = light, voltaic = volts. There are 3 types of cell, monocrystalline is the most expensive with best output ( ignore amorphous and polycrystalline ).

Now back to the 3.41A. He missed the 43V peak. This tells me it's designed to work at about 36V. The controller will take in 36V at 3A and convert it to 12V at 9A ( approximate figures to make it easier to understand ). That 12V at 9A = 108W is in line with their sales figure.

But you never get anything like that 100W in the real world.

And the "h" that keeps creeping in. That is connected with time to charge or drain the battery. An 85Ah battery, will provide 8.5A for 10 hours. Yes ? NO. Because you can't take a battery down to empty without killing it that 10 hours is dropped to 5 hours for a normal battery or 7 hours for a deep discharge battery.

Back to your 100W panel. Take a guess at 50%, 50W. Your 85Ah battery is half discharged so you need 45Ah to go back in.

50W from panel. 50W / 12V = 4A

45Ah needed so 4A for 11h does it. But when do we get 11h of sunshine :Sad:

[ All number have been simplied to make it easier to understand ]
funnerly anough brian,i could almost feel you breathing down my neck when i was trying to help this guy out,but did wait awile,because i noticed you logged on and thought you might help him:thumb:
the only thing i got wrong was the p/v bit as i thought they were all different??:Blush:,as far as the voltage goes i did,nt noticed the voltage in the spec,and done the sums on max output as stated in spec:thumb:
but fair play you caught me out, :thumb::thumb:
but a lesson learned on my part,cheers teach:winky::thumb:
i just also noticed that im the one only pulled up???intresting?
 
Nov 30, 2009
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Hi! Ralph, what sort of price are these batteries?
Cabbyshack

They are not cheap , by any means.
We were very lucky and were given 2 by a mechanic friend of ours who works on fork lifts and plant. A favor for a favor :winky:
They were new and are brilliant , in as much as we can use the electric as much as we need to just having the solar panel to top up.
They are even strong enough for the Webasto diesel heating , which has a fan that totally drained the old ones we had.
We found the normal leisure ones that were fitted were useless in the winter as we learnt the first time we used it in - temps :RollEyes:


They have some on ebay just put in trojan batteries I did but the link i did didnt work.



Look here for them for an eg. First one that came up on google. You may get better deals else where.

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hilldweller

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Dec 5, 2008
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but fair play you caught me out, :thumb::thumb:
but a lesson learned on my part,cheers teach:winky::thumb:
i just also noticed that im the one only pulled up???intresting?

It's not about catching out or you Chris, it's about me really. I watch some threads, some I cannot believe what is being said but they are harmless, some dangerous and need a comment or risk loss of sleep and some get to the stage where I think some poor sod must be confused to death and I comment.

My comment to yours was on the basis of time for accurate information, nothing personal.

We've no solar, I can't convince myself we would benefit at all, moving, the van charges the batteries, 'er indoors demands campsites so hook-up is usually available and often included in the pitch. We easily manage 4 days off 110Ah.
 

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