Midnite Classic CC only going thru One Charge Cycle per Day

MrM1MrM1 Registered Users Posts: 487 ✭✭✭✭
Perhaps this is what it is supposed to do, but my Midnite Classic 150 will only go thru one charge cycle a day. 

I changed my load needs so that I am almost not using an power at night and the batteries only see about a 3-5% discharge all night.  I used to discharge down to about 60-70% every night,  now its no more than 94%+ nightly.  (I am off grid by day / on grid at night unless power outage)

I never recalled this to be an issue when it took most of the day to recharge,   but now,  I am fully charged by 10am each day.

Here is the problem.  if the sun comes up and it is sunny, I am charged by 10am.  I go off grid at 9am.  System is in Float by 10am or at the latest 11am   But if clouds roll in at noon I start using more battery because the solar array cannot keep up with loads.  This may discharge me down to about 80% sometimes more.  BUT ... the Classic never goes back into a charge cycle,  it just stays in Float.  If the sun comes back out at 3, there would be enough sunlight to recharge,  but not if the system only stays in Float at 27.9v (yes I have float set too hi for a 24v system for this reason)

I can force an Absorb charge,  but don't really want to have to think about this.   Is this Normal for a Classic to only have 1 charge cycle in a day?   Is there a way to get it to start a 2nd charge cycle automatically if the batteries need it?    I have the Classic Rebulk setting set to - 8 and the days between bulk set to - 0.

Maybe this is typical behavior, but I do not know because I've changed the way I use the system.
REC TwinPeak 2 285W 3S-3P 2.6kW-STC / 1.9kW-NMOT Array / MN Solar Classic 150 / 2017 Conext SW 4024 Inverter latest firmware / OB PSX-240 Autotransfomer for load balancing / Trojan L16H-AC 435Ah bank 4S connected to Inverter with 7' of 4/0 cable / 24 volt system / Grid-Assist or Backup Solar Generator System Powering 3200Whs Daily / System went Online Oct 2017 / System, Pics and Discussion

Comments

  • mcgivormcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    Check the recharge voltage setting of the controller, in most offgrid situations it is undesirable to promote an additional charge cycle unless required,  so as not to add to the cycle count of the battery. Being that .you have grid and are attempting to optimize solar during the day to offset the grid useage , you may want  to rethink your  strategy, remembering of course  that battery power is almost always  more expensive than grid power. Should the solar input be incapable of supporting the loads the makeup energy should come from the grid, not the battery.

    Float voltage is a value where the battery is neither being charged nor disharged, setting it artificially high will have an adverse effect as it would be approaching a charge value. Some serious thinking into priorities is in order, are you willing to sacrifice the battery in an attempt to reduce grid consumption ? A loosing battle if you ask me. An option none the less.
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • VicVic Solar Expert Posts: 3,114 ✭✭✭✭

    The Classic has a setting,  called   '   ReBulk  '

    This defaults to 8V.   You can change this default value to the battery voltage at which you wish the new charge cycle for a given day,  begins.

    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.
  • MrM1MrM1 Registered Users Posts: 487 ✭✭✭✭
    Thanks both responses help. 
    REC TwinPeak 2 285W 3S-3P 2.6kW-STC / 1.9kW-NMOT Array / MN Solar Classic 150 / 2017 Conext SW 4024 Inverter latest firmware / OB PSX-240 Autotransfomer for load balancing / Trojan L16H-AC 435Ah bank 4S connected to Inverter with 7' of 4/0 cable / 24 volt system / Grid-Assist or Backup Solar Generator System Powering 3200Whs Daily / System went Online Oct 2017 / System, Pics and Discussion
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