Which Batteries ?????

Discussion in 'American RV's' started by do1977, Nov 24, 2009.

  1. do1977

    do1977 Read Only Funster

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    i have just fitted 4 x 110 amp batterys ( £70 each cheep ones ) for the living as it already has 2 x 6v batterys linked to make 12v

    they have been charged up priply and the 230v & 12v charger are working
    they dont hold much charge as they run out after 3 or 4 days and all the lights are LED and the tv is 12v and the only thing else i have is a laptop

    i am thinking do i need to replace them with better ones or not??
     
  2. scotjimland

    scotjimland Funster Life Member

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    With the limited information I would say NO ..

    first you need to check:

    1. that they are being charged properly .. how do you know they are full ? Do you use a hydrometer ?

    2. Calculate how many amps you are using over the time period..
    add up the hours of TV + lappy etc and calculate the total amps used.

    3. you say you have two existing 6v in series, they may be dragging the new batteries down.. if you are certain the new ones are being FULLY charged then I suggest disconnecting the old 6v and do further trials ..



    as an aside. I have had 4 x 85 cheap FLAs ( £30 each) for four years and still going strong

    hth

    jim
     
    Last edited: Nov 24, 2009
  3. do1977

    do1977 Read Only Funster

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    the 6v batterys where new in july i was told if i was to get more battery which ones should i get and why??
     
  4. hilldweller

    hilldweller Funster Life Member

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    Something very wrong there.

    We get 3 or 4 days out of one 85Ah.

    So:
    1. Your batteries are not being charged properly.
    2. There is something draining them you don't know about.
    3. The batteries are no good.

    I'd take this battery by battery. One faulty one could discharge the others. Just have one on line at a time. Monitor the charging which should hit about 14.5V. See how long it lasts.

    Do you have any means of measuring the current out of the battery ?

    I wouldn't think you'd been sold 4 duff ones but stranger things have happened.
     
  5. MicknPat

    MicknPat Funster

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    do1977,

    Have you worked out how many parasite appliances or devices you have in your RV,
    these can be all sorts of things from CO2 detectors, radio / cd player displays, clocks, fridge/ freezer, our fridge freezer fro example requires a 12 volt input even if run off gas.

    I would suggest you when ALL 12 volt items are off that you check what current is being still drawn from the batteries.

    Not sure how you do this :Blush: but I'm sure some one will know on here?

    Mick
     
  6. pappajohn

    pappajohn Funster Life Member

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    what is the max rated output of your onboard charger ?

    you have 440ah of new batteries added to the other two which may total 110ah or, i suspect, even more.

    thats a total of at least 550ah.
    a standard charger will really struggle to charge those fully.

    a 10amp charger may take over 40 hours to charge to 550ah if the batteries are just about flat.
    you should aim for a minimum charge rate of 10% of your toal battery reserve...ie 55amp charger.

    i would say you need at least an 80amp charger...preferably a 3 stage charger capable of a high charge rate of 14.4v at least.
     
  7. do1977

    do1977 Read Only Funster

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    i have a 40amp 3 stage charger high charge rate of 14.4v so i dont think the charger is the problem as i also hve 500w of solar that i hve tested for discharge at night

    so it must be a battery whats the best way to test them apart from taking them all off and seeing how long they all last one at a time
     
    Last edited: Nov 24, 2009
  8. pappajohn

    pappajohn Funster Life Member

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    i figured it was worth a mention incase you had a crappy charger...:Wink:

    i think you may have to check each in turn to be sure if one is iffy.

    i think the best and quickest way would be to get a hydrometer and check the electrolyte specific gravity.
    this way you know immediately and dont need to disconnect each battery.

    hydrometers arent very expensive and you've get one for future use.


    you may get a very slight difference cell to cell but any big difference will indicate a knackered cell/battery.

    heres a chart showing different voltages and gravity's at different charge states.
     

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  9. scotjimland

    scotjimland Funster Life Member

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    as I suggested
     
  10. vwalan

    vwalan Funster

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    You could beg steal borrow or buy a drop tester .sealey do a nice one .there are some deals going on i got one for 32 quid the other day at tragomills in cornwall. means charging them up then individually clipping on and pressing the button but they work quite well.
     
  11. do1977

    do1977 Read Only Funster

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    just got one off ebay and will see what they are like


    if i ws going to replace and batterys has any one used these before YUASA 6 VOLT 160 AMP DEEP CYCLE POWER LEISURE BATTERY on eBay (end time 02-Dec-09 18:29:59 GMT) ???????
     
  12. do1977

    do1977 Read Only Funster

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    as i already hve 40 amp charger

    i also have a 20amp 3 stage charger as well in the garge
    can i conect both at the same time????????
     
  13. pappajohn

    pappajohn Funster Life Member

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    i'd really want to know the age and history of the batteries first.
    if they have been used as UPS batteries there would be a maintainance record on them.
    they could have been used on electric forklift trucks and recycled many times.

    i dont like the sound of this either...

    charged by a standard 12v charger.

    12v batteries can be charged up to around 14.8v then they start to gas badly.
    a 6v could maybe be charged at 8 or 9v but at 12v it will gas and overheat badly and not last long at all.

    i'v melted a 6v battery accidently put on a garage 12v 20amp charger and it didnt take long.

    of course this wont apply as you would be fitting two to make 12v or multiples of two to up the amps.
     
    Last edited: Nov 25, 2009
  14. do1977

    do1977 Read Only Funster

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    so could the 2x 6v batterys not be to good

    well i wont to get this sorted as i have room for more batterys so if i was to ad to them what battery should i get??
     
  15. pappajohn

    pappajohn Funster Life Member

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    as i said in my edit it will be ok as you will join two in series to make 12v then another two joined the same way and connect to the first pair in parallel to increase the amps but still 12v.

    pos of 1st battery to neg of second to make it 12v
     
  16. do1977

    do1977 Read Only Funster

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    yes that is done already

    can i use 2 chargers??
     
  17. pappajohn

    pappajohn Funster Life Member

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    a lot of RVers use2 x 6v batteries in series as the ampage is usually much higher than one 12v

    joining two banks of 2 x 6v in parallel will double the amps and still be 12v
     
  18. pappajohn

    pappajohn Funster Life Member

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    cant see why not......you use the onboard charger AND a solar panel at the same time without problems so two chargers amount to the same thing.
     
  19. do1977

    do1977 Read Only Funster

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    so what is the best batterys to use?
     
  20. pappajohn

    pappajohn Funster Life Member

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    i've always use regular 12v 110ah lead/acid leisure batteries.

    i have 3 making 330ah.

    120w panel on the roof and a 25amp 3 stage onboard charger.
     

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