Outback FM80 decided to skip absorb today

benthere
benthere Solar Expert Posts: 113 ✭✭✭
in Off Grid Solar & Battery Systems #1
My Outback FM80 decided not to do an absorb cycle and floated for 8:09 instead. Kind of a bummer since it's the rainy season and we only absorbed for 0:41 yesterday. My last FM80 did this trick once or twice too (this is a replacement unit). Is this some sort of known problem?

Thanks,
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  • rplarry
    rplarry Solar Expert Posts: 203 ✭✭
    #2
    Re: Outback FM80 decided to skip absorb today

    My FM80 has never done that, and I hope it dosen't. Have you posed this question over at the Outback forum?
    Larry
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  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #3
    Re: Outback FM80 decided to skip absorb today

    must be a new mode.
    instead of absorb, it's abort.:p

    wish i could help you on that one.
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  • jalbers
    jalbers Registered Users Posts: 13 ✭
    #4
    Re: Outback FM80 decided to skip absorb today

    That's interesting. The 1st FM80 we had did the same thing. We only had it a few months, so I contacted Outback......and they shipped me a new one. I would keep an eye on the one you have and if it happens again....................

    Jerry
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  • boB
    boB Solar Expert Posts: 1,032 ✭✭✭✭
    #5
    Re: Outback FM80 decided to skip absorb today

    Just for grins, check your minimum absorb time setting and make sure it's not
    set to some real small amount of time.
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  • benthere
    benthere Solar Expert Posts: 113 ✭✭✭
    #6
    Re: Outback FM80 decided to skip absorb today
    boB wrote: »
    Just for grins, check your minimum absorb time setting and make sure it's not
    set to some real small amount of time.

    Off the top of my head, the absorb time is set to 6-hours and absorb end amps is 0 (disabled).
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  • boB
    boB Solar Expert Posts: 1,032 ✭✭✭✭
    #7
    Re: Outback FM80 decided to skip absorb today
    benthere wrote: »
    Off the top of my head, the absorb time is set to 6-hours and absorb end amps is 0 (disabled).

    Is that 6 hours the MAXIMUM absorb time or the MINIMUM absorb time ?

    The absorb time varies and depends on how long it was in bulk.
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  • benthere
    benthere Solar Expert Posts: 113 ✭✭✭
    #8
    Re: Outback FM80 decided to skip absorb today
    boB wrote: »
    Is that 6 hours the MAXIMUM absorb time or the MINIMUM absorb time ?

    The absorb time varies and depends on how long it was in bulk.

    The setting is listed as "Absorb Time." I suspect it is both the minimum and maximum.

    Edit to add. I'm not entirely sure I have the latest firmware but it should be current within a year or so. Has there been a major revision?
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #9
    Re: Outback FM80 decided to skip absorb today

    Absorb Time is a maximum figure. if it is set for 6 hours, the charge controller will not stay in Absorb for longer than that. Normally Absorb length is determined by how long it takes to reach the Voltage set point during Bulk.

    Check and see if the Absorb End Amps has been set to a number other than zero. If it has some high value in it the Absorb will end immediately if the charge controller needs less than that current to maintain Absorb and supply any loads.
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  • benthere
    benthere Solar Expert Posts: 113 ✭✭✭
    #10
    Re: Outback FM80 decided to skip absorb today
    Cariboocoot wrote: »
    Absorb Time is a maximum figure. if it is set for 6 hours, the charge controller will not stay in Absorb for longer than that. Normally Absorb length is determined by how long it takes to reach the Voltage set point during Bulk.

    Interesting since it rarely goes to float before putting 6 hours on the absorb clock (except when it decides to skip absorb). I check the numbers almost daily from the mate. Sometimes it's just a few minutes under or over 6-hours on the absorb clock.
    Cariboocoot wrote: »
    Check and see if the Absorb End Amps has been set to a number other than zero. If it has some high value in it the Absorb will end immediately if the charge controller needs less than that current to maintain Absorb and supply any loads.

    It's set at zero.
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #11
    Re: Outback FM80 decided to skip absorb today

    Just out of curiosity, how long does your Bulk cycle take? You should be able to get something like 32 Amps from your panels, and although that's a little low it ought to suffice for fairly rapid charging of a 450 Amp hours @ 48 Volt battery bank (unless there are significant loads drawing at the same time). Most of us don't have enough sunlight to do a Bulk charge and stay in Absorb for six hours!

    The inconsistent nature of the FM's behaviour leads me to believe it has a fault, rather than a programming error.

    The ol' MX60 design is still the champion, in my opinion. :D
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  • boB
    boB Solar Expert Posts: 1,032 ✭✭✭✭
    #12
    Re: Outback FM80 decided to skip absorb today

    How about this ?
    Did the FM80 go to sleep the night before and start its Bulk the next day ?
    i.e. When it was MPPTing, was it "BULK MPPT" ? (might show "B MPPPT")
    and then go to Float ?

    Or did it maybe show "Float MPPT" ? ("FLT MPPT") ?

    Some times the MX/FM had trouble going to sleep (Zzzzz....) for enough time to start a new Bulk cycle... But that probably isn't it either since it used to start a new BULK cycle every 24/25 Hours even if it didn't go to sleep. (Alaska, Land of the MidNite Sun etc)

    Just thinking out loud and probably has nothing to do with the problem.

    boB
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  • benthere
    benthere Solar Expert Posts: 113 ✭✭✭
    #13
    Re: Outback FM80 decided to skip absorb today
    boB wrote: »
    How about this ?
    Did the FM80 go to sleep the night before and start its Bulk the next day ?
    i.e. When it was MPPTing, was it "BULK MPPT" ? (might show "B MPPPT")
    and then go to Float ?

    Or did it maybe show "Float MPPT" ? ("FLT MPPT") ?

    Some times the MX/FM had trouble going to sleep (Zzzzz....) for enough time to start a new Bulk cycle... But that probably isn't it either since it used to start a new BULK cycle every 24/25 Hours even if it didn't go to sleep. (Alaska, Land of the MidNite Sun etc)

    Just thinking out loud and probably has nothing to do with the problem.

    boB

    I think there might be something to this argument given the very short absorb time of the previous day. The day was so bad that the CC didn't recognize night as night? On the other hand, the history log sees it as a separate day so I guess the CC does too? Also, the absorb time was never reached.

    I didn't watch it actually happen to see what the display said, but the log recorded 8 hours of float so ???

    On clear days our bulk cycle is about 3 hours. We're in the monsoon now so we haven't seen many of those in the last few weeks.
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