numax 85ah is it time to replace it

Discussion in 'The Beginner' started by craig.drake, Oct 29, 2011.

  1. craig.drake

    craig.drake Read Only Funster

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    im a bit puzzled the battery shows green fully charged but after just one hour the tv goes off lights and other stuff still work fine battery still shows green,it was in the van when i got it in june 2010 ive topped water up (took almost a litre) i think i might need a new battery thinking of a good quality 110ah as i might need to rely on it for wild camping in scotland in the not to distant future
    by the way our tv is a 19" 60w 5.0a and when its on the vans volt needle drops from 12v to 11.5v
    is such a big tv to much for a battery??
     
  2. old-mo

    old-mo Funster Extra Special Life Member

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    I have just replaced my two (2) Numax`s and both had the green window showing OK..

    But having them checked they were at the end of their life..:Sad:

    Not really up on electrics though..so cannot help you sorry.
     
  3. Snowbird

    Snowbird Funster Life Member

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    IMO one 85 amp leisure battery is the next best thing to useless for watching TV and all the other stuff you have in a MH even if its new. A 110 amp wont last long either for watching TV,water pump,lights,fan heater and all the other drains you will require. If off hookup you will need at least 330 amps and solar to put back what your taking out.
     
  4. craig.drake

    craig.drake Read Only Funster

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    mmm we use gas off hook up for heating
    i thought a 110ah would be ok for odd night off grid for a bit of tv and light etc, not enough room for any more
     
  5. Snowbird

    Snowbird Funster Life Member

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    OK you use gas when off hookup but do you not have 12 volt fans circulating the heat.
     
  6. craig.drake

    craig.drake Read Only Funster

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    aahh isee of course no its just the fire ive often wondered what blown air would be like but its our first mh so we dont know what we are missing i suppose:Laughing:
     
  7. Snowbird

    Snowbird Funster Life Member

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    You wont believe how much juice the water pump needs and if you have normal bulbs,not LEDs then there's nothing left out of an 85amp battery for a 19" TV. If you seriously want to sever the umbilical cord then you will have to consider solar and a larger battery bank.
     
  8. craig.drake

    craig.drake Read Only Funster

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    ive thought of a gennie but dont fancy it really storing it would be a pain
    are solar panels good enough ? especially in winter :Doh:
     
  9. jonandshell

    jonandshell Funster

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    Most 'leisure' batteries are next to useless. Many are just re-labelled starter batteries and do not have the construction suitable for repeated deep discharge.

    I would advise you to bite the bullet, shell out the cash and buy a good quality proper deep discharge battery. These will last you ten times longer and give reliable performance for wild camping.

    We use 'Dyno' traction batteries. Although an open unit, they do feature condensing cambers on the caps, just like 'maintenance free' batteries and so far, topping up has been barely called for.
    We bought ours from a local forklift battery specialist.
    Other makes worth googling would be Hawker, CMP and Trojan.
    As a guide, we have 2x 115AH Dyno monoblocs and these will run our van for three days straight at well below 0 degrees. This is with the Webasto Dualtop running 24/7 and no rationing of lights and telly! Well worth considering if you have a skiing trip!:Smile:

    Useful link-

    http://www.trojan-batteries-online.co.uk/
     
  10. Snowbird

    Snowbird Funster Life Member

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    Am running 3 X 110 amp batteries charged by 2 X 75 watt solars and a small wind turbine at the moment and NEVER need hookup. Am in Wales at the mo and today's weather was terrible but have enough power stored for TV and laptop use with LED lights and heater fan. Everything I have is 12 volt, I don't use inverters. I know a good solar system is expensive but over a short period of time by not having to use campsites that are now charging in excess of £25 per night you will get a return,and as a bonus you will be able to watch TV when you want.
     
  11. pappajohn

    pappajohn Funster Life Member

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    in answer to your question.....yes, the battery is knackered.

    you should never discharge below 50%/12.1v....which seems to be your indicated start point.

    Here is a table to help you determine the state of charge of a 12-volt battery:

    battery volts......Percent of Charge

    12.73v.............. 100%
    12.62v.............. 90%
    12.50v.............. 80%
    12.37v.............. 70%
    12.24v.............. 60%
    12.10v.............. 50%
    11.96v.............. 40%
    11.81v.............. 30%
    11.66v.............. 20%
    11.51v.............. 10%

    these figures are for a battery with no load....put it under load and the figures will be slightly lower.
     
  12. jonandshell

    jonandshell Funster

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    The '50% rule' only applies to the 'leisure' batteries mentioned in my previous post.

    Proper deep discharge lead-acid batteries of quality manufacture are able to be discharged safely to 20% time and time again without damage.

    I know what I'd rather spend my cash on..................
     
  13. Snowbird

    Snowbird Funster Life Member

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    Can I just say one thing regarding looking after batteries. Buy or build as we have done a desulfator and leave it coupled up to your battery bank. I know this sounds a bit strange but they take very little power from your batteries and stop the batteries prematurely dieing of sulfation which is the only cause of battery failure. Boat people have been using these things for years but for some odd reason the MH fraternity have not cottoned on yet.
     
  14. slobadoberbob

    slobadoberbob Read Only Funster

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    You will get lots of views on that

    You will get lots of views about solar.. those that have them will say yes and others will say no.

    I have 2 x 85amh Numax batteries in our RV .. like you size of the underfloor storage are dicates the size for us. we are in to the third season with them. I suspect we will change them for next year season to be on the safe side.

    But we do have a Sterling invertor / charger - the 4 stage type that is linked to our 4 kw generator fitted on our chassis. this or EHU supplies power through the Sterling to our batteries or the inverter 230 v sockets. we also monitor the power use with a NASA MB1 that tells us how our batteries are holding up, charge in and use out etc., All our light bulbs are now leds to cut down drain.. but pumps and boiler fans use a lot of power.

    We are going to have a battery to battery charger fitted next season.. that (Sterling again) fools the alternator to put extra power out to charge a second battery bank (in this case the one on my car trailer).. then I will have another large battery that will allow me extra domestic power .. the battery is there for the winch if I need it... as we drive the car on, it is not used very often and that means I have spare battery power that can be used in the domestic side of the RV.

    Have looked at wind power recently.. but a) expensive b) to big and c) not enough power return for my needs.

    Look at solar... a) to heavy b) not enough roof space and c) in the UK not enough sun to get a decent return on the investment.. just my views when I compared everything..

    The battery to battery works for me, well I hope it will as not cheap for the unit and to have it all fitted etc., but this will work as I have the car trailer and a fittted large battery box on it. But that would not apply to most people.

    Bob:thumb:
     
  15. slobadoberbob

    slobadoberbob Read Only Funster

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    following on to my post last night

    Following on from my post last night on the issue of the Numax battery.. I decided to day to check mine.

    These have been on the RV for about 2 1/2 years now... there are two of them I fitted type XV24MF these are 86 amp ... they are a sealed unit, but i noticed both the green condition bits had gone to clear.. according to the print on the battery they need to recharged.

    now these are connected to mt Sterling Pro Combi 1500 watt invertor / charger from the 230v mains outside the house. I disconnected them and one battyr was showing 12.9 and 13 dead... the NASA BM1 showed that they are chraged as does the Winnebago gauge on the panel. So it seems I will be changing the pair soon.

    I checked prices on the internet and found Tayna.co.uk could do the battery at £72.89 plus £9.00 delivery = £161.74 for the two. I also found them direct on ebay from a dealer in gloustershire for £147.94 delivered 4- 6 days... I did also find a slightly bigger Edurolite from Tayna at 90 ah for about £16 on each battery...

    I will check my normal supplier and see how near he gets to those I have found.

    The issue is size that I can get in the locker (under the floor via a hatch part under hte slideout).. also it has the double poles and screw units for the power and earth cables.

    So the hunt starts.. I may also try Lincoln Batteries in Essex and see what they can do for me... the batteries are sealed for life type so no topping up.

    Bob
     
  16. 1_man_and_his_dob(lo)

    1_man_and_his_dob(lo) Funster

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    Can one of these revive a 'dead' battery?

    It sounds like my leisure battery (which I've had since I bought the 'van 18 months ago) is in a similar state to craig.drake's - I put this down to
    a) it perhaps not being a very good battery (it's the original Diamond, and calls itself a 'semi-traction' battery :Mellow:) - the indicator always shows green so the phrase involving a chocolate fireguard comes to mind;
    b) me discharging it heavily many times, thanks mainly to my compressor fridge and blown-air heater :Blush:

    I'm wondering whether it can be rescued and then used as a backup to something that can cope better with my usage pattern, like the ones jonandshell mentions.
     
  17. Snowbird

    Snowbird Funster Life Member

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    Hi Niel, In SOME cases a desulfator will revive a dead battery. I have had some success with revival but it depends how far gone they are and how long you are prepared to wait for a result. Have just got a 110 amp back to life and its holding 12.7 and has done for 6 days,so am pretty confident with that one. If your interested I got a kit from Courtistown on ebay and we built it up. They now sell them ready made but obviously that's not as much fun.
     
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