inverters

Discussion in 'Motorhome Chat' started by bazfergy, Sep 30, 2009.

  1. bazfergy

    bazfergy Read Only Funster

    Joined:
    Apr 20, 2009
    Messages:
    566
    Likes Received:
    3
    Location:
    dumfries scotland
    Hi guys ive got a 85watt solar panel fitted and ive got a 110ah leisure battery im planning on fitting another 110ah battery so i can do away with my gennie, the big question is what size inverter should i use i would want to run a tv and satellite charge phones etc no microwave ive been told this uses a lot of power. Thanks in advance barry:thumb:
     
  2. scotjimland

    scotjimland Funster Life Member

    Joined:
    Jul 25, 2007
    Messages:
    28,934
    Likes Received:
    25,574
    Location:
    .
    Hi

    Good question because sizing is important, too big it will be inneficent and waste power, too small and it will cook .. soo

    Decide how many appliances you will connect at the same time, add up the watts and buy an inverter with about 20% spare capacity ..

    Example

    TV = 80 watt
    + Sat receiver = 30 watt

    Total 110 watt.. + 20% = 132 watts

    Ideal inverter 150 watt

    jim
     
  3. Terry

    Terry Funster

    Joined:
    Dec 27, 2007
    Messages:
    10,722
    Likes Received:
    6,224
    Location:
    South yorks
    Simple get everything to run on 12v (more efficient) and don't bother with the inverter :thumb: works for me.I have / had a 700 watt inverter in the garage but have never seen it since buying it :Rofl1:
    terry
     
  4. stagman

    stagman Deleted User

    I wouldn't bother much with an inverter . 12v TVs and other accessories are cheap enough . We do have a 1000w inverter which the wife uses very sparingly with her hair drier .:thumb:
     
  5. scotjimland

    scotjimland Funster Life Member

    Joined:
    Jul 25, 2007
    Messages:
    28,934
    Likes Received:
    25,574
    Location:
    .
    While I agree that it would be better if everything was 12v , an inverter is invaluable for charging such things as phones, laptops, cameras etc and for powering games machines, DVD, Sat box, TV etc etc.
    Replacing existing 230v kit with 12v or buying 12v adaptors can work out a lot more expensive than a small inverter .. and if it's properly sized is almost as efficient as 12v adaptors ..
    But as in all things in life, it's horses for courses.. and the wallet often dictates our choice.

    jim
     
  6. Neckender

    Neckender Funster

    Joined:
    Oct 15, 2007
    Messages:
    977
    Likes Received:
    1,197
    Location:
    Stoke on Trent or Benidorm
    I have twin 85 amp batteries, part led lighting, 800 watt invertor from macro £43, 240 volt tv also recharge ,shaver, phones, etc, webasto diesel heating, no solar panel fitted. We have just done 2 seperate weeks holiday with no hook up.

    John.
     
  7. vwalan

    vwalan Funster

    Joined:
    Sep 23, 2008
    Messages:
    7,594
    Likes Received:
    3,853
    Location:
    roche cornwall
    hi harleyjohn did i see shaver. thought you would have a great long beard . you letting the side down.
     
  8. hilldweller

    hilldweller Funster Life Member

    Joined:
    Dec 5, 2008
    Messages:
    26,475
    Likes Received:
    25,170
    Location:
    Macclesfield
    Have you done the sums.......

    85 watts, at very best 7 amps. Realistic 5 or less.

    110 / 5 = 22 that is over 22 hours under best conditions to charge one battery. I'll leave it up to you to work out how long to charge two.

    Don't scrap that gennie too quickly.
     
  9. Beachbum

    Beachbum Read Only Funster

    Joined:
    Sep 13, 2007
    Messages:
    215
    Likes Received:
    1
    Location:
    Hamburg / Cornwall
    Hi Stagman. I too have a 1000w. If your Mrs uses a hairdrier, can I use an 800w toaster. I know from what folks tell me, I will need a 2500w Inverter for a 800w toaster. Or can I get away with it for just making 2 slices of toast once a day.
     
  10. hilldweller

    hilldweller Funster Life Member

    Joined:
    Dec 5, 2008
    Messages:
    26,475
    Likes Received:
    25,170
    Location:
    Macclesfield
    You need to talk to a better class of folks !

    800W is 800W.

    800W also represents 75 amps from your battery which will probably last one hour on an average battery. So how long do you intend cooking toast ?
     
  11. RichardnGill

    RichardnGill Read Only Funster

    Joined:
    Sep 22, 2007
    Messages:
    199
    Likes Received:
    1
    Location:
    Durham
    In practice you would only run your battery to 12Volts so you would only need to put aprox. 55AH back in.

    We have an 85w Solar and 2* 110AH batterys, yes the solar does not fully charge them up each day but it will make them last a lot longer and we have 2 kids and 2 TV and a lap top on a lot of the time when we are away.


    We have a 150w Inverter which use to power out TV and sat box no problem, but now we have gone to 12v Tv's and sky box the inverta only charges the lasp top now. I find the inverter uses more power to run the Tv than a 12V TV will use.

    Rich...
     
    Last edited: Sep 30, 2009
  12. vwalan

    vwalan Funster

    Joined:
    Sep 23, 2008
    Messages:
    7,594
    Likes Received:
    3,853
    Location:
    roche cornwall
    thought 800watts will be the output not the input
     
  13. robinmclaren

    robinmclaren Read Only Funster

    Joined:
    Feb 23, 2009
    Messages:
    345
    Likes Received:
    32
    Location:
    coventry , warwickshire
    he is right

    the output is at 230/240v which is 20 x of the input voltage so what ever ampage you draw out in theory is x 20 as loss from battery
    so yes 5 a @ 230v = nearly 100a drain from 12v battery

    we have a 800w deep fat fryer and this drops our battery voltages rapidly when on invertor and can only use sometimes

    our lcd tv/dvd from comet had a 240v/12vdc adaptor so scrap adaptor and run direct from 12v ( ampere unit in line to protect in case of surges/overvoltage )
    most phones direct from 12v car chargers
    gameboy and psp charge from 12v adaptors
    inverter only used for wifes dryer and straightners ( apparently these are essential and must work where ever we are or life is over )
    we do have 2 large solar panels and did over 2 weeks in cornwall this year ( weather crap and not much sunlight ) and were just starting to run low by end , but no genny and no starting engine

    we will see how it survives in disney new year although am loading a genny just in case
    :Cool:
     
  14. Beachbum

    Beachbum Read Only Funster

    Joined:
    Sep 13, 2007
    Messages:
    215
    Likes Received:
    1
    Location:
    Hamburg / Cornwall
    Hi Brian, Some guy in Spain a couple of summers back said whatever wattage you use, your Inverter should be 3 times more powerful, i.e: 800w x 3 = 2400w. If you disagree, what wattage Inverter should be used for 800w. Toasters usually take about 1 1/2 to toast. Will my 1000w Inverter do the job without causing a problem?
     
  15. haganap

    haganap Funster Life Member

    Joined:
    Dec 5, 2007
    Messages:
    11,070
    Likes Received:
    13,681
    Location:
    Heavan
    I too have everything running through 12v. I can charge phones, laptops and games this way. I also carry a small genny for making sure my batteries stay tip top when wilding for more than a couple of nights or in winter time.

    I carry just a small inverter just in case, Nikki has a 12volt set of hair equipment or gas? not sure which :Blush:

    I would keep the genny.:thumb:
     
  16. robinmclaren

    robinmclaren Read Only Funster

    Joined:
    Feb 23, 2009
    Messages:
    345
    Likes Received:
    32
    Location:
    coventry , warwickshire
    i guess we will all be making the most of our mains hook up next weekend then, bet all the women bring mains dryers etc , etc
    must load my chip fryer !!
     
  17. Tony Lee

    Tony Lee Read Only Funster

    Joined:
    Sep 28, 2008
    Messages:
    274
    Likes Received:
    1
    Perhaps he sells inverters.

    It depends on what you are running from the inverter. Loads incorporating compressors or other non-commutator motors do require a large surge to get them started and although all inverters have short -term ratings much higher than continuous, the electronics are often not able to cope with the surge so a higher rated inverter will be required.

    purely resistive loads such as toasters and electric kettles also have a small surge when starting but this can easily be handled by the inverter so an inverter with a continuous rating equal to the appliance rating would cope. 1000W would run an 800W toaster but of course a single 100Ah deep-cycle battery is really not designed to deliver that sort of current. Two in parallel would be kinder.
     
  18. Beachbum

    Beachbum Read Only Funster

    Joined:
    Sep 13, 2007
    Messages:
    215
    Likes Received:
    1
    Location:
    Hamburg / Cornwall
    Hi Tony, I have 110AH x 3. I will have a go and use the 800w toaster tomorrow. The MH is outside the back door in case I have to boost up the batteries. Thanks Buddy.
     
  19. Tony Lee

    Tony Lee Read Only Funster

    Joined:
    Sep 28, 2008
    Messages:
    274
    Likes Received:
    1
    Only thing that might happen is if the batteries are down a bit, you might get the inverter tripping out because of low input voltage.

    You could check your inverter specs but generally would be something like 1100Watt continuously, 1500W for 5 minutes and something like 2000W for 5 seconds.

    For other applications involving motors or other loads with a non-unity power factor, inverters can have a lot of trouble but that shouldn't be the case for a toaster.

    BTW - I use a toaster consisting of fine SS mesh that sits on the gas burner and the bread sits on a rack about an inch above. Makes perfect toast in seconds and no inverter needed.
     
  20. hilldweller

    hilldweller Funster Life Member

    Joined:
    Dec 5, 2008
    Messages:
    26,475
    Likes Received:
    25,170
    Location:
    Macclesfield
    I wonder if he's fallen foul of switch on surge at some time. An 800W inverter and 800W motor could be a problem because startup current could be very much higher for the first second or so. Probably the same with a microwave.

    But a toaster is purely resistive, has no switch on surge so 800W should work. It's nice to have a bit of spare so 1000W sounds fine, unless you are a battery and it sounds like hell on earth. I don't think you'll have any problem with that short time providing the battery is OK and if it isn't it will let you know. Your inverter will shut down before it damages the battery - allegedly.
     
Loading...
Similar Threads
  1. Brakers
    Replies:
    61
    Views:
    1,570

Share This Page