Ok, heres what I think I need.

Discussion in 'Solar Power' started by wireman, Jun 12, 2009.

  1. wireman

    wireman Read Only Funster

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    Right to start with I am going to:
    1 Change all lights to CEL type(12 of)
    2: Buy another battery (85amph) to give me 170 amph in total.

    I use:

    Mainly lighting, but of course water pump etc and fridge on gas. Occaisionally use heating on gas but of course needs leccy for the fan. We also have need to charge mobiles and laptop We occaisionally watch the TV or watch a movie so maybe 2 hours a day absolute max. We tend to move everyday, but occaisionally we will stay in one place for 2 -3 days.

    I have given up on gennies, fed up of lugging them about then not starting just when you need them despite having tested the damn thing just before you leave.

    So I want solar more, I think, as a backup rather than a neccesity (given the increase in battery size and light power reduction). However I suspect, being my usual self and over engineering these things and costing myself money for stuff I don't use......

    I reckon I can get away with a 60w or thereabouts panel (we tour mainly in the summer but the van is used most days in the winter as a form of transport) probably wired in via the onboard charging unit if it has connections but otherwise through a regulator.

    Does the panel think that that wilol be adequate or have I missed something?
     
  2. Wildman

    Wildman Read Only Funster

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    your heading in the right direction however if you can afford it up the panel size to cover you on those wet miserable days when you get minimum charge but max TV use. We manage with 50W but have 2 x 120amp/hr batteries and move every day, never do sites, only shows so no hookup and never used the genny (but come close)
    Three weeks away last autumn with rain most days really was stretching it. 80W -130W would have left us with some to spare, but then our TV only draws 1 amp, not 4 or 5, this year will have to change to a digital using 4 amp so will need more panels
     
  3. wireman

    wireman Read Only Funster

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    not sure what the tele draws but its a flat screen 15" jobbie and tbh we only use it in the UK (which is not often) for TV, it mainly serves for the odd film, we tend to read a lot when we are away. So I may up that to 80w mono. I have thought of trying to make up some kind of mount that I can tilt the panel a bit, although my other idea was to maybe get 2x 40w and mount them in a shallow upside down V if you see what I mean...also we tend to go to bed early and read at night so light consumption comes to the head of the list again.
     
  4. Wildman

    Wildman Read Only Funster

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    15in would be 4-8amp. at a guess, a bit more than my old 7" B/W 1 amp job
     
  5. GJH

    GJH Funster Life Member

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    Have a look at This Thread from a few days ago where similar matters were discussed. You may find helpful information.

    Graham
     
  6. mark e

    mark e Read Only Funster

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    What generator let you down ? Surly not a Kipor or a Honda :Wink:

    I use a genny through the day when needed, off and on.

    After spending about 800 pounds on the motorhome, tv, pots and pans, propene gas, external screens etc, the additional 300 pounds was the best money spent for the genny :thumb:
     
  7. pappajohn

    pappajohn Funster Life Member

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    the good thing about solar panels is they arent JUST a backup system......they are just there.....working all day for free(after the purchase price of course) even in winter/rain/cloud and they only weigh about the same as a small genny or less.:thumb:
     
  8. The Wild Ones

    The Wild Ones Read Only Funster

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    FWIW as our first mains independant outing was at stratford, we thought it would also be a great chance, just to see how we would cope just on battery. The outcome was optimistic, by using all onboard equipment sensibly accordingly to the control panel when we departed there appeared hardly any movement on the CP.

    FTR we always use the onboard shower,cook wash up etc, read and watch a hour or two of TV a day. I am in the process of changing G4 bulbs for LED and fitting a Solar Panel as we are intending to use commercial sites less and less.

    The big test for us will be in the summer when we are intending to `wild it' as much as we can :Smile:
     
    Last edited: Jun 14, 2009
  9. Douglas

    Douglas Read Only Funster

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    As a comparison only, I offer my own details

    Batteries = 300 amps
    Solar = 200 watts

    I use TV 4 hours
    Computer 4 hours
    plus all the other services

    In sunny Spain I never run out of amps and by the morning before the sun starts work I always have the voltage above 12.3 and the batteries are full again by mid afternoon

    If there is cloud or I am further north then its not so good. In the UK I would have flat batteries in 2 > 3 days.

    Doug
     
  10. keith walker

    keith walker Read Only Funster

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    hi please help. not very good at this game.had solar panel fitted.ok no probs but would like to fit a 2nd battery of the same size.not sure of cable size and fitting to battery.thanks keith
     
  11. Douglas

    Douglas Read Only Funster

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    The bigger the better, (with in reason) I use 30 amp cable for the solar panel to battery and try to design a system that has the shortest runs. If you have large inverter ( say 1 KW or bigger) then use starter motor type cable to feed it from the battery, and again keep the cable runs as short as possible.

    The reason for the heavy cable and short runs is to keep the voltage loss as low as posible


    Good luck

    Doug...
     
  12. falcon

    falcon Read Only Funster

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    solar ac power

    Does it make set up a 170w solar panel on roof and wired into a second leisure battery (say 85AH) to work the AC system when not hooked up. That should work the telly daytime and possibly some small appliance for short periods. Would I need an isolator to hook up on site?

    Comments welcome.
     
  13. pappajohn

    pappajohn Funster Life Member

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    hi Falcon,

    no, you wont need to isolate the solar panel if on EHU.

    depends on how many amps the aircon needs and whether its 12v or 230v through an inverter but with a 170w panel and only charging one 85ah battery you will have a lot of wasted solar power. theoreticaly 14amps but in reality maybe 10amps+ of solar power on a good day.

    my aircon has a running current of around 3 amps at 230v but through an inverter that goes up to 60ah from the 12v battery.
    if its through an inverter you will be very lucky to get three quarters of an hour from your 85ah battery.
    link both batteries together and charge them both off the same panel :thumb:

     
  14. falcon

    falcon Read Only Funster

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    solar ac power

    Papajohn,

    I follow most of that and it all makes sense. However, if I am to replace the hookup power with solar, I have to use an inverter to get 230V at the wall sockets.

    If I charge the third battery whatever its capacity in tandem with the existing leisure battery, I will not get ac power to the wall sockets right? unless I am missing something here. The circuit indicates a direct supply to the sockets from the hookup socket.

    From what you say there is a large loss in using the inverter and I can understand that to a point but how else can you replace the hookup ac power?

    My TV/Sat receiver is AC and lots of other low power appliances are similar.
     
  15. pappajohn

    pappajohn Funster Life Member

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    sorry falcon....completely mis-understood your problem...

    i thought you were refering to Air-Conditioning unit 'AC' not mains AC.:Doh:

    to run the 230v socket etc you would need to run a flex cable from the inverter to the EHU socket outside the van and turn off the onboard charger. thats the easiest and safest way.
    if you leave the charger turned on you are in fact recharging the battery though the onboard mains charger which is being powered from the inverter, via the EHU socket, but the inverter will be taking a lot more current from the battery than the charger can put back into the battery. hence...turn it off.

    make sense?
     
  16. gazznsam

    gazznsam Read Only Funster

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    if you want to get away from the orange umbilical cord... you really need to do a bit of re-designing of the vans electrical system,

    you really need as many items as possible running on 12 volts,

    lights are easy, infact not many motorhomes have mains lights (afaik) halogens are the worst for sucking power, fluorescents are much better, better than fluorescents are cold cathode tubes, and even better than all that are led's, but led's are still fairly narrow beam, so more suited for reading lights.. tho the strips of leds may do the job.

    tv and sat reciever, i assume it's a flat screen TV?? if not then seriousely think about changing it, the old cathode ray tube TV's pull a lot of power (unless it's a small B&W one :)
    the TFT tv's are much more energy efficiant, if it's below 19 inches in size then it probably runs on 12 volts... if it has a power brick in the middle of it's power lead, then you could replace that with a DC-DC regulator (amperor. gets loads of mentions on this site), that is a lot more efficiant than starting off with 12 volts DC, inverting it upto 230 volts AC, then converting it back down to 12 volts DC... you'd be loosing about 30+% of the power in heat in the inverter and psu.

    the sat reciever, unfortunately there was only one sky badged digital reciever that runs on 12 volts, the pace javelin, also known as the pace 1000, or the sky mini box, they can be bought new for about £100,
    but you could use a small inverter to run just the Tv and sat box, remembering to turn the inverter off when ever you arent actually watching the thing.

    if you have a laptop, buy a 12 volt power supply, costs about 35 quid, but much more efficiany that running the mains psu off an inverter, my laptop pulled upto 6 to 7 amps off the inverter, it pulls no more than 5 amps, and more usually 3 amps when using the 12 volt power supply.

    phone charging... get car chargers... most supermarkets with an electrical dept.. i.e. a tesco extra, asda wallmart etc, sell a universal car phone charger, you get the fag lighter bit, coily cable and a selection of ends, me and sam have different phones, so that saves us taking 2 chargers with us, just change the end and charge the phone up, it also has a usb charging jack end so i can use it to charge my sat nav as well,

    for inverters, if you have a big battery bank, then a big whole van inverter can be handy, that's what i have, but my inverter pulls over 2 amps before it even powers anything (it's quintisential current, what it uses to run it's own electronics) so if i used that to run a mains phone charger, the inverter is consuming more power than the charger is,

    so it is better to have a few small inverters to power sets of equipment, i.e. if you dont want to change the Tv for a 12 volt one, then have a small 300 watt inverter just for that, if you dont want to get a 12 volt laptop psu, get one of those little 150 watt 'coke can' type inverters to run the mains psu.

    if you have some large electrical loads, then a whole van inverter makes sense, my inverter is used to run the washing machine, centeral vacuum system, sams hairdryer, the microwave and so on, all big loads where the 2 amps the inverter pulls is insignificant compared to the 150 amps the hoover is pulling.

    just remember to do what papajohn says, if you run an inverter make sure you turn the charger off, some chargers can be dammaged if you dont,
    before i fitted my automatic change over relays to my system, i once accidentaly left the charger on whilst i had the inverter on, the batteries were flattened in super fast time and it was the inverters low voltage alarm that alerted me to the problem, opening the charger locker door i was hit by a heatwave, both the inverter and charger were red hot, the charger was buzzing and pulsing like hell, the inverter beeping like mad as the overheat alarm went off too.
     
  17. falcon

    falcon Read Only Funster

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    Thank you so much Papajohn. Your advise is sound . All I have to do now is find where to switch off the mains charger. However now I understand the issues and pitfalls, I can happilly work out a failsafe switch off method. Thanks again.:thumb:
     
  18. falcon

    falcon Read Only Funster

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  19. Baker69

    Baker69 Read Only Funster

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    Are there any lights with LED's to replace the old fluorescent tube strip lights?
     
  20. hilldweller

    hilldweller Funster Life Member

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    I have seen them but the flourescents are so efficient you save little if any electricity. I've not seen the LEDs in use, basically a long strip of them which may not give the same light output as the efficient florescent.

    Bottom line is florescent is damned good. Which you may have guessed from all the energy efficient bulbs in use now, and everywhere in Morocco which was a bit of a surprise.
     
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