AGM Batteries

Discussion in 'Tech/Mech General' started by iandsm, Sep 8, 2014.

  1. iandsm

    iandsm Funster

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    Does anyone have any thoughts/ recommendations on AGM batteries. I am in France now and the 5 yr old lead acid Elecsols are struggling. I was thinking about some Varta 95 AGM's and there is a dealer not to far away.
     
  2. TheDogMan

    TheDogMan Funster

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    Varta are excellant batteries
     
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  3. John Laidler

    John Laidler Funster

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    Agm are a type of sealed battery although they can vent if there is a fault. More expensive than a traditional wet cell battery and with a shorter life but much safer in a MH.
     
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  4. Peter_n_Margaret

    Peter_n_Margaret Read Only Funster

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    We have used Fullriver AGMs in Austraila with excellent results. The best cycling model is the DC range.
    Fullriver have excellent data on their web site.
    Full cycling daily for 200+ days each year plus running the fridges for the rest of the year (we never turn them off) we get 5 years plus life which is considerably longer than typical wet cell life under the same conditions.
    Their other useful feature is that the self discharge rate is much lower than wet cells, so they can be left much longer in storage without a top up and without damage if all loads are disconnected.

    We would not use any other type of battery, except perhaps LiFeO in the near future.

    Cheers,
    Peter

    EDIT. I don't know the Varta brand, and have no reason to think they won't be fine.
    I would buy any AGM ahead of any wet cell every time.
    Peter
     
    Last edited: Sep 10, 2014
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  5. scotjimland

    scotjimland Funster Life Member

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    I wouldn't waste money on AGM or GEL .. buy good quality flooded lead acid, but don't take my word for it..

    Before deciding read this Advice from Sterling..

    and their conclusion
    The best battery to use for fast charging using advanced charging systems

    • For general leisure use: use low cost Lead Acid which can be topped up with water. So called leisure batteries
    • For long term cruising then use 6 volt traction
    Avoid Gel / AGM for 3 reasons
    1. very expensive
    2. their fast charger rate causes them to gas
    3. poor cycling numbers.
     
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  6. Peter_n_Margaret

    Peter_n_Margaret Read Only Funster

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    I have never seen ANYONE else EXCEPT Stirling make those recommendations.
    I do agree that GEL are more problematic, but our PERSONAL experience with AGMs for 10 years is as I stated above. For 12 years prior to that we used wet cells. Never again.

    Cheers,
    Peter
     
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  7. Pat4Neil

    Pat4Neil Read Only Funster

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    I agree, Charles Sterling is the most narrow minded man I have ever spoken too. He is on his own with that opinion. There are several types of batteries out there and all have their own strengths and weaknesses.

    Cost is a big factor

    Neil
     
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  8. Stroppy Bird

    Stroppy Bird Funster

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    I replaced my the battery on my van with a VARTA AGM. I kept with an AGM simply due to it's location in the hab area and no external vent tube required. I've not had any problems with it and most of our trips away are not on Hook Up.

    I seem to remember an article in the caravan club mag some time ago where they tested a number of batteries from different manufacturers and chopped them up to see their internal workings. VARTA and one other came out top of their tests. I saw this after I had bought the VARTA, so was pleased with my decision. Plus it's dimensions were such that it was the biggest amp battery that I could fit in the gap available.
     
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  9. iandsm

    iandsm Funster

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    Thanks everyone useful information.:)
     
  10. scotjimland

    scotjimland Funster Life Member

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    Interesting that you know him.. never thought the advice was narrow minded.. far from it, as far as I am aware, Sterling don't sell batteries, so no axe to grind ..

    There is no doubt in my mind that 'bang for buck' a flooded lead acid is the best choice and if you can afford them, buy deep cycle traction batteries, such as Trojan..
    I had four 120ah cheap FLAs in my RV and they were fantastic.. had them for 5 years ( 3 years full time) and when I sold the RV they were still going strong.. most of that time was not spent on EHU, so they were well used.

    I've only ever had one AGM, by Elecsol, and it failed within three years and was never impressed by it's performance.. .. so to echo Peter's view of FLAs .. .......... AGM.. never again..

    Out of interest Neil, what have you chosen for your 'new build' overland motorhome , GEL, AGM or FLAs ?
     
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  11. Steve

    Steve Funster Life Member

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    Got to agree with jim on this price wise, but the new agm batteries are good but pricey. Not a good idea to use with a high load inverter.
     
  12. lunarman

    lunarman Funster

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  13. scotjimland

    scotjimland Funster Life Member

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  14. Pat4Neil

    Pat4Neil Read Only Funster

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    4x 120 ah Sonnenschein Gel Batteries , wired for 24v.

    I can take these down to 30% and the volts are still at 26 +

    Sterling supply some great products and I am currently considering his B2B charger.

    The point I am making is that all batteries have pros and cons and having spoken to Charles Sterling on the phone his attitude is that he is the only person who knows anything and everyone elses opinion is wrong.
    he is famous for this.

    Batteries are personal choice. It will often depend on budget and space to house them.

    Some people might not want batteries venting into their habitation area, some people ( Like me ) are too lazy to check fluid levels all the time and top them up .

    Battery manufactures make it very hard to do comparisons between their product and others by measuring their performance in different ways. Some batteries claim a large Ah capacity, but in reality when they are 20 % down the volts are so low that nothing works any way . The don't mention this in their spec.

    Its what ever suits you.

    Elecsol where a con and I also had problems with some I bought, which is probably why he went under.


    Neil
     
  15. Steve

    Steve Funster Life Member

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    Below is a few lines from the link that lunarman gave. Makes for intresting reading. thanks to lunarman for the link.


    If your battery is twice the age of the warranty, we strongly suggest you replace it. If the Manufacturer thought it would still perform at its best for longer, it would have a longer guarantee.
    However, the primary reason we advise a Wet Acid battery, apart from saving a lot of money and charging more quickly,
    is because in the majority of Motorhomes the Charger unit charges both Starter and Habitation Battery.

     
  16. Pat4Neil

    Pat4Neil Read Only Funster

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    If your charger can't be set to different algorithms for different battery banks then this would make sense.

    Neil
     
  17. Bobby22

    Bobby22 Funster

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    Reading through both the above links AGM batteries may not be suitable for modern motorhomes. The charging systems in modern MH may fail with AGM.

    The new technology in the Bosch/Varta may be the way forward i have a stop/start car and there can be a big drain on the battery in the winter. The engine starts on its own if the drain at a stop becomes too long.
    5 year warranty and totally maintenance free so we can wait and see.

    With the above theory they might even last 10 years.
     
    Last edited: Sep 10, 2014
  18. TheCaller

    TheCaller Funster

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    The second part of that quote is true (charging both batteries), but it's not the whole story.

    In some motorhomes, the charger output can be switched between the two batteries, or simply joined together. If this is the case, then the quote applies & the batteries should be the same type. But if that is the case, the whole system is pretty basic & probably should be replaced if you need very much from your batteries.

    Modern vans, especially continental conversions, have a multi-stage charger that should be set for the type of habitation battery fitted. They do also charge the starter battery, but automatically & only at a maintenance rate - in effect they act as a trickle charger as far as the starter battery is concerned, just to replace what is lost by self-discharge, alarms & radio use. In this case it shouldn't really matter if the starter battery is a different type. As an example, the Schaudt Electrobloc EBL99 provides an automatic float charge to the starter battery of 2A max

    I find it a surprising quote, given its source, because they are the specialists in exactly the type of charger where it shouldn't matter.
     
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