How much Charge do you get from your solar panel

Discussion in 'Motorhome Chat' started by Wildman, Feb 26, 2009.

  1. Wildman

    Wildman Read Only Funster

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    I checked my solar panel today at midday when the sun was at its highest. 50W panel was only giving 1/2 an amp, it has a theoretical max output of 4 amps, and may well achieve that in the summer so I got to wondering, what do you get from your panel please give Date, panel size in watts, location, and amps reading taken at midday Which given the weather would be time of max reading. Could be an interesting referance if we kept adding readings throughout the year in different weather conditions. I'll start with todays reading.

    26/02/09 50W, Devon, Sunny, 500mA.

    bring on the sunshine :thumb::thumb::thumb::thumb:
     
  2. pappajohn

    pappajohn Funster Life Member

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    wont work Roger.....
    could give a reading on saturdays and sundays but a lot of us work during the week.....:RollEyes:
     
  3. scotjimland

    scotjimland Funster Life Member

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    Interesting post, I look forward to seeing the results, there are some wild claims made on here about solar panel output. :RollEyes:

    Paradoxically, the time of year when you need it the most is when the output is at a minimum.. I have thought about fitting, but as I don't need them in summer there would be little point in fitting for winter use as I would still need an EHU..

    Jim
     
  4. Wildman

    Wildman Read Only Funster

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    Right John, did I say every day? As far as I know there is a midday on both Saturday and Sunday, either would do. Just the occasional reading summer/winter sunshine/dull now is that too difficult just to get an idea of what panels are ACTUALLY producing
     
    Last edited: Feb 26, 2009
  5. Diabalo

    Diabalo Funster

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    To save starting another thread, what would be a suitable size panel to keep the vehicle battery charged up, I have one of those little jobbies you see in camping shops and it is about as much use as a cat flap in a submarine.
     
  6. Wildman

    Wildman Read Only Funster

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    Hi Dane, what sized panel depends on how many amp/hr you are likely to use, or are you just talking of replacing natural wastage when laid up in the winter. For keeping the engine batteries topped up (from the likes of imobiliser light, alarm etc. a 10W panel should be sufficient and not need a regulator. Most people who can afford it have between 50W and 180W on the leisure side some have 2 x 180W panels but more batteries are cheaper. Another thing to think about is how often do you move, every day, or sit in one place for a week. 50W and 2 x 20 amp/hr batteries saw us ok for a three week trip in October, but we are low power users and do move every day. Keep an eye on this thread for replies to get an idea of what to expect charge wise.
     
    Last edited: Feb 27, 2009
  7. Diabalo

    Diabalo Funster

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    Thanks for the info Roger.:thumb:

    It's just to keep the engine batt topped up as it is in storage and the little panel I have isn't keeping up with the loss.

    I am up at the Newark show in march and will see what is on offer.
     
  8. sinbad1

    sinbad1 Deleted User

    Found this makes for some good reading on solar pannels and also gives a calculator of what to expect .

    click here


    Regards
     
  9. Wildman

    Wildman Read Only Funster

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    please don't clutter this thread with other posts it will make it difficult to read, just add your readings as above. Thanks.
     
  10. Wildman

    Wildman Read Only Funster

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    Maybe it would also be a good idea to include the type of panel, poly or mono crystaline or what ever. These old style panels are only 15-20% efficient, the new breed of multi connect panels claim to be up to 40% efficient. That will help things along.
     
  11. pappajohn

    pappajohn Funster Life Member

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    28/2/09 12.00 Scarborough
    120w polycrystalline
    heavy cloud
    700ma
    batteries charged
     
  12. Douglas

    Douglas Read Only Funster

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    200 watt in 3 panels ----at latatude 26' ---- 13:54 -----8.5 amps----- into 300amp battery

    The panels are laying flat at the moment, no need to angle them at the moment.

    Doug
     
  13. oldun

    oldun Read Only Funster

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    As a solar panel will only give an output anywhere near the quoted value when the sun is perpendicular to the panel the output for a fixed, lay-flat panel, at this latitude even in the summer will be low. Clouds partial/full shading from trees and TV aerials/sat dishes etc will further reduce the output.

    We just have to accept that the out of such a panel will at its best being only a small fraction of the quoted value.

    The advantage a fixed panel is that it will always be producing an output, no matter how small, during daylight hours - even on the move.

    An adjustable panel can produce a larger output but only when it is regularly adjusted to face the sun.

    Portable panels can only produce an outfit when the outfit is stationary and the owners are around to ensure its safety.

    It would be interesting to find out the average watts hours of electricity produced each week of use, by each of the systems, for each quoted watt of panel output. I imagine the lay-flat panel would win hands down as it will be working every hour of daylight.

    Any takers?
     
  14. sinbad1

    sinbad1 Deleted User

    Too many variables to come to any one conlusion IMO
     
  15. ocsid

    ocsid Read Only Funster

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    The initial premise that you can theoretically get 4 Amps from a 50 Watt panel is unfortunately badly flawed.
    That would be the case if they were rated at 12 volts but typically they are rated at about 17 volts on the panel.
    So a 50 Watt panel at best will only give 2.94 Amps.

    This is confirmed in "sinbad1's" link;
    quoting:
    "Right, here we go! It seems that individual modules are typically meant for a 12-volt system like ours, and are rated with a wattage number (like 120). Now, this doesn't actually mean that they produce 10 amps, because their working voltage is substantially higher than 12 - ours are rated at 16.9V."
     
  16. pappajohn

    pappajohn Funster Life Member

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    :Doh:not working roger...
     
  17. Wildman

    Wildman Read Only Funster

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    To be honest John I believe reading the purpose of the thread and the posts is just beyond most members, they all want to show how clever they are or how stupid I am, posting the details I asked for would allow anyone to make informed decisions about spending a huge amount of cash on solar power. Personally I am beginning to think wind power may be a better route to go. so once again.
    This thread is for readings only please discuss the ins and outs pluses and minuses in another thread. Thank you.
     
  18. oldun

    oldun Read Only Funster

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    I apologise for leading the thread astray but when one is asked certain questions the mind always leads on on to other associated questions - hence my contribution.

    Having said that I would estimate that about 80% of replies to posts are not on the main topic and many are full of juvenile drivel that some take for humour.

    keeping to the topic is something we (me in particular) should learn.
     
  19. sinbad1

    sinbad1 Deleted User

    Perhaps you could justify this comment ? as far as i can see the so called off the topic posts were all directly related to solar pannels all beit to improve the data collection.(non of which warrent your comment).

    I personally make no appology for providing information in order to improve the data collection.

    I was not intending to make any further comments on this post as Wildman has made it quite clear it is a read only; but feel a response is justified.

    Still think that this is a good idea Wildman, and as the OP respect your wishes.

    Regards
     
    Last edited by a moderator: Mar 4, 2009
  20. oldun

    oldun Read Only Funster

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    Sorry another misunderstanding - my comments related to posts (in general) and not the posts to this thread.

    What I was referring to the posts where someone makes supposedly humorous comment which is meaningless to 99% of the readers. The next post is then a few smileys, followed by another opaque comment... ad nauseum. These are just pure drivel but seem to be welcomed by a few of the readers. If anyone can explain how these type of posts add anything to the forum in general or the original post in particular then please do so. They are nothing more than graffiti.

    Naturally they are OK in the "off-topic" type of forums but not in any of the technical ones.

    I accept that none of the post in this topic are of of that type and I never inferred that they did.

    We must all accept that either:

    1. We all stick absolutely to the request in the original post. In this case most of the posts here do not directly answer the question asked and therefore should be removed.

    or

    2. We can stray somewhat providing there is a relationship between the original post and the later ones is closely related. I thought, perhaps mistakenly, that my first post fell into this category.

    So if my first post is to be criticised then so must most of the others which also did not supply the data requested.

    I am happy to accept justifiable criticism but it should be even handed.

    I think it's time we all lightened-up a little and got back to the topic in the original post.
     
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