AGM status when gone for long periods

santaigo
santaigo Registered Users Posts: 22 ✭✭
Small system in off grid cabin in Baja Mexico. Two 190 watt panels, thru Xantrex C60 controller to four 12v Deko 105AH AGM batteries. Xantrex 1500 watt modified sinewave inverter/charger to power center.  The batteries will be new and a BTS will be used.  The cabin is shut down for 4 to 6 months at a time; what would be the best way to leave the system when gone?
Thanks

Comments

  • Estragon
    Estragon Registered Users Posts: 4,496 ✭✭✭✭✭
    I would open all the breakers on charge sources and loads, with fully charged batteries. AGMs generally have low self-discharge, and are best left alone and fully charged for that length of time. If I could bury them, I would.
    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
  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    High temperatures will accelerate the self discharge, which if left too long may damage the batteries beyond recovery, if possible store them in a climate controllled location. Leaving them connected and unattended is an option i personally would not be comfortable with for that length of time, too much could go wrong. Then again the distance between Ensenada or San Felipe and LA Paz or Cabo San Lucas is around 2000Km, if left in winter in the north, it would be significantly cooler than the south, so it largely depends on location and season.
    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.