Battery Box

I have have a small 100w panel with one 100AH deep cycle hybrid gel battery.  My off grid cabin is visited about once or twice a month.   My temps get to 15 degrees on a regular basis.  The panel should stay free of snow.  I am thinking of using a cooler as a battery box to best retain the heat.  I have also thought of using a small heater that will turn off when the temp is above 77 degrees in the cooler.  

Does this sound viable?  What kind of ventilation should I have in the cooler?

Thanks

Comments

  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    Lead acid batteries suffer no ill effects when cold as long as they are fully charged, the best approach would be to fully charge thendisconnect the battery before leaving, this would ensure that nothing goes wrong in your absence, which is when things usually do go wrong.
    The battery will warm up inside the cabin assuming it's heated, a battery box isn't really nessersary nor is the heater, the battery is sealed, only venting if overcharging is occurring.

    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.
  • jgregoire687
    jgregoire687 Registered Users Posts: 2
    McGivor,
    Thanks for the reply.  The cabin is not heated, except when we are there.  We heat by woodstove.  I was under the impression that the charge controller prevented the battery from overcharging, am I mistaken?

    Thanks
  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    Yes that is correct, the controller is/should be designed to prevent overcharging, but given that the temperatures are low, thus resulting in low self discharge, along with extended absence, it would be better to disconnect everything to play it safe. Nothing worse than arriving to find things have failed due not being there, which ironically often is the case.
    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.