batteries - used Rolls or?

System
System Posts: 2,511 admin
in Off Grid Solar & Battery Systems #1
Hello all,

Great forum here! I live in NW Montana, off-grid for 16 years now and
love it.

Started with a generator and 4 L16's, then added pv panels and
upgraded to 16 L16's. Our batteries are 7 years old and need to be
replaced (quick charge/discharge plus one bad cell so took out 1 string).

I would love to go to industrial batteries but just cannot afford it.
However, I have come across 4 Rolls 6CS 21PS batteries, 4 years old
and always well maintained. But what I am assuming is the date on
the battery shows "6122004" meaning they would be 6yrs old? The
price is $800 for all which sounds good to me, based on the new price.

Any advice is greatly appreciated..:)

~Carla

System: 24V Ananda APT Power Center/Trace SW4024 inverter/4-80W Solec panels/8-75W Siemans panels/16(now12) Trojan L16 batteries/10kw Lister-Petter diesel generator
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Comments

  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #2
    Re: batteries - used Rolls or?

    getting used batteries is always a risk and if the date stamp shows they're older then they are older. in any case we don't normally advise mixing batteries of different makes, models, and age as they will be drawn down to the level of the worst batteries in the bunch. if you accept that the rolls may not be that good and is a stop gap measure just to buy you time until you get around to replacing the whole battery bank, then fine, go for it, but it is your call. it is sometimes a tough call as to whether to replace just those that fail, replace none with diminished returns, or replace all of them.
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  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    #3
    Re: batteries - used Rolls or?

    New price is ~$900 @ or +- $3600 for the four.

    Do you know who had them? Why are they letting them go? How did they use them? How did they "maintain"?

    I would consider trying to do a load test, but that would be pretty hard with such a large set of batteries I would guess. But if I was satisfied with the answers to the above questions I might take the chance. I might also make a lower offer on the the theory that there are not too many people in too many places who will buy them.

    FYI, the NAWS site suggests that these are designed for a ~20 year life cyle. So in that case, 6 years is ~1/3 gone. I certainly wouldn't pay more than 1/2 of 1/3 for them or 1/6, or ~$600.

    Tony

    PS Considering all of the above, these four batteries would be considerably less AH capacity than 16 L16's. (~6000ah for the 16L-16's as opposed ~2200 ah for the Rolls (6 volts) so I don't think I would add these to your existing string, nor would I use these as the start of a new string. All things considered, you have a bit of a conundrum I think.
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  • RCinFLA
    RCinFLA Solar Expert Posts: 1,485 ✭✭✭✭
    #4
    Re: batteries - used Rolls or?

    Check rested voltage and SG. If good, may be worth the risk.

    As from movie 'Forrest Grump' : used batteries are like a box of chocolates. Never know what you are going to get.
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  • blackswan555
    blackswan555 Solar Expert Posts: 246 ✭✭
    #5
    Re: batteries - used Rolls or?

    I would not recommend SH batteries but if push comes to shove, A few questions I would be asking

    Service history & SG`s / EQ records from the initial commissioning and all other's subsequent ones,
    Have any cells changed much in relation to each other from "new" do all of the cells rise in temp about the same as the others?

    What DOD were they using ? ( greater than 50% may be an issue)

    Did they have temp sensing ? ( if not may be an issue)

    What charge V & A, what system, where, Operating conditions/ environment/ loads,

    If the above is reasonable, Ask the owner to have them fully charged, then go along and do a 2hr EQ,
    What do the cells look like after ? Is the electrolyte dark or cloudy? A little fairly evenly across all cells is normal, If they are uneven or very dark, Could point to problems,

    Have a good one
    Tim

    ps they are 683 ah @ 20hr
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  • trkarl
    trkarl Solar Expert Posts: 33 ✭
    #6
    Re: batteries - used Rolls or?
    JustRSize Acres wrote: »
    Hello all,

    But what I am assuming is the date on
    the battery shows "6122004" meaning they would be 6yrs old?
    ~Carla

    System: 24V Ananda APT Power Center/Trace SW4024 inverter/4-80W Solec panels/8-75W Siemans panels/16(now12) Trojan L16 batteries/10kw Lister-Petter diesel generator

    The date code for Rolls batteries is a four digit number stamped on the + lead terminal.

    "The four digit date code represents the day of the week (first digit), week of the year (middle two digits) and the year (last digit)"
    http://jgdarden.com/batteryfaq/carfaq7.htm#freshness

    Or just call their tech support to confirm the age of the batteries. I had an issue with my batteries and the tech confirmed that is the date code.
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  • solorone
    solorone Solar Expert Posts: 257 ✭✭✭
    #7
    Re: batteries - used Rolls or?
    trkarl wrote: »
    The date code for Rolls batteries is a four digit number stamped on the + lead terminal.

    "The four digit date code represents the day of the week (first digit), week of the year (middle two digits) and the year (last digit)"
    http://jgdarden.com/batteryfaq/carfaq7.htm#freshness

    Or just call their tech support to confirm the age of the batteries. I had an issue with my batteries and the tech confirmed that is the date code.

    Just saw this, and checked my Rolls, nothing stamped, not on front of case or terminal, LOL no one punched the label dates either, have to check, think they are 8 years old.
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  • blackswan555
    blackswan555 Solar Expert Posts: 246 ✭✭
    #8
    Re: batteries - used Rolls or?

    Whiles age is an issue, how many cycles, to what DOD @ what ah rate @ what V , Service history and if they were temp compensated is more important,
    Roll`s say 3000 > 3500 cycles at spec`d A, V, DOD, ah &Serviced, Go either side of their recommendations and you could get less or more than that, A bit like a used car, Just cause it is not old , does not mean it has been looked after or driven well.

    Tim
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