Skip days on Classic 100

rp3703rp3703 Registered Users Posts: 123 ✭✭

I know this has been discussed before but I am worried my circumstances may make my situation different. We have a 24V system with two banks of four deca 6V FLA’s. We are here in Northern Ontario during the month of July and gone the rest of the year. Right now we have our Classic set to the regular cycle of Bulk, Absorb and Float with no change while we’re gone. I would like to set some skip days while we are gone but I’m a bit worried about sulfation occurring from a lack of bulking. Also, I found nothing in the manual on how to set the classic up for skip days. Anyone know a good resource for this?

1860 W (6) Rensola JC310M, Classic 150, [email protected] (8) Deka DSGC15 FLA's, Victron Phoenix Multi 24/2500 Inverter
Powering-20.5 CuFt. Fridge, 1 HP Submersible water pump, UV, Washing Machine, Gas Dryer, Gas Stove, Lights and Receptacles
Off Grid Cottage on lake in Northern Ontario 46˚N 

Comments

  • EstragonEstragon Registered Users Posts: 4,451 ✭✭✭✭✭
    I have skip days set at 10 days.  If you have the Midnite LocalApp, it's easily set/changed in that.  With it set, the controller goes straight to float unless the bank gets down to rebulk voltage, or every 10 days, whichever comes first.  Sulfation isn't an issue, as the bank stays full or nearly so.  Floating daily just basically offsets self-discharge to keep the bank full.

    Doing a bulk/absorb cycle every 10 days or so just makes sure the electrolyte gets mixed so it doesn't stratify.  Doing it daily isn't needed on an idle bank.
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • rp3703rp3703 Registered Users Posts: 123 ✭✭

    So on the front panel, you can scroll to the “Skip Days”parameter. I just bumped it up to 10. Is that all I need to do?

    1860 W (6) Rensola JC310M, Classic 150, [email protected] (8) Deka DSGC15 FLA's, Victron Phoenix Multi 24/2500 Inverter
    Powering-20.5 CuFt. Fridge, 1 HP Submersible water pump, UV, Washing Machine, Gas Dryer, Gas Stove, Lights and Receptacles
    Off Grid Cottage on lake in Northern Ontario 46˚N 
  • EstragonEstragon Registered Users Posts: 4,451 ✭✭✭✭✭
    edited July 2019 #4
    Pretty much.  In L.A , there's a confirm/save button.  IIRC just changing the value in the MNGP display saves automatically, but it's been a while as I find L.A. much easier for  settings.

    I usually like to confirm things are working as expected before leaving.  You could set rebulk way down to confirm it goes straight to float the next morning, then put rebulk back up to be sure it comes out of float as expected.

    I assume you've already figured out snow shedding on panels (like putting some vertical), and charging voltages are working well for you.  Also assuming a single classic.


    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • rp3703rp3703 Registered Users Posts: 123 ✭✭

    Well, we didn’t have time to tilt up the panels last year and the bats managed to make it through the winter but yes, we have tilted them for this winter. Don’t want to to push our luck. Yes on the single classic as well. Thanks for the tip on dropping the bulk voltage. We only have a few days left and I definitely want to make sure it’s working before we leave. 

    1860 W (6) Rensola JC310M, Classic 150, [email protected] (8) Deka DSGC15 FLA's, Victron Phoenix Multi 24/2500 Inverter
    Powering-20.5 CuFt. Fridge, 1 HP Submersible water pump, UV, Washing Machine, Gas Dryer, Gas Stove, Lights and Receptacles
    Off Grid Cottage on lake in Northern Ontario 46˚N 
  • AYHSMBAYHSMB Registered Users Posts: 4
    Where should bulk voltage be set under normal circumstances?
  • rp3703rp3703 Registered Users Posts: 123 ✭✭
    Depends on your battery’s specs. 
    1860 W (6) Rensola JC310M, Classic 150, [email protected] (8) Deka DSGC15 FLA's, Victron Phoenix Multi 24/2500 Inverter
    Powering-20.5 CuFt. Fridge, 1 HP Submersible water pump, UV, Washing Machine, Gas Dryer, Gas Stove, Lights and Receptacles
    Off Grid Cottage on lake in Northern Ontario 46˚N 
  • rp3703rp3703 Registered Users Posts: 123 ✭✭
    Hey Estragon, this is probably a stupid question but do you turn off skip days while you are at you cabin or do you keep the 10 day skip on all the time?
    1860 W (6) Rensola JC310M, Classic 150, [email protected] (8) Deka DSGC15 FLA's, Victron Phoenix Multi 24/2500 Inverter
    Powering-20.5 CuFt. Fridge, 1 HP Submersible water pump, UV, Washing Machine, Gas Dryer, Gas Stove, Lights and Receptacles
    Off Grid Cottage on lake in Northern Ontario 46˚N 
  • EstragonEstragon Registered Users Posts: 4,451 ✭✭✭✭✭
    I leave it set.  My 12v bank doesn't get discharged much at this time of year, as it's mainly running a very efficient 12v freezer, and 12v lighting which isn't needed much with long days.  As such, it can go days without getting to rebulk and goes straight to float with SOC in the mid 90% range.  IMHO, that's good, because at that SOC there's little chance of hard sulfation.

    My 48v bank gets more load for water pumping, AC fridge, etc.  It will occasionally skip a day, but most days does a bulk/absorb cycle just as it would without skip-days set.  Once or twice I've forced a bulk ahead of gloomy weather just to be sure it's as full as possible, but mostly it just works.
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • VicVic Solar Expert Posts: 2,985 ✭✭✭✭
    rp3703 said:

    So on the front panel, you can scroll to the “Skip Days”parameter. I just bumped it up to 10. Is that all I need to do?

    rp3703,

    When setting Skip Days from the MNGP (or any other parameter in the Classic),  remember to press Enter when you are done with that page.

    Many/most of we Classic users still use the Arst function,  which,.   essentially re-boots the Classic at Midnight,  local time.   If the parameter that was set,   was not saved by  ' Enter ',   after local MN,   the Classic will use the previous value of the parameter that had been Entered,   until it is changed again.

    FWIW,   Vic
    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH [email protected], 11.1 KW STC PV, 4X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  25 KVA Polyphase Kubota diesel,  Honda Eu6500isa,  Eu3000is-es, Eu2000,  Eu1000 gensets.  Thanks Wind-Sun for this great Forum.
  • EstragonEstragon Registered Users Posts: 4,451 ✭✭✭✭✭
    Good catch.  I forgot about the enter thing on the MNGP.
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
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