Emergency Lighting and Data Power in an Off Grid System

richardimorserichardimorse Registered Users Posts: 98 ✭✭
edited December 2018 in Solar Beginners Corner #1
I just got my head around scrapping the batteries in an old battery bank, either by:

1) Hospice care by someone who wants to baby sit the last drops of power from them and manage their end of life
2) Selling them to a recycling centre who can reclaim the Lead and handle disposal

But perhaps their is an application for several of my 24 * 12 Volt 230Ah batteries after all:

What I was thinking is to take the best 8 of the 230 Ah 12V batteries and leave them on a 24V charger in float in the same way that a Prime Generator often has its battery on a 12V charger when used with an AMF or AGS system providing a DC loads battery bank of 920Ah

Then to use DC power from these 8 batteries (no more inverters) and POE injectors for WiFi and Cameras

1) Battery room lighting 
3) iPhone and Samsung Galaxy S charging points
3) External Internet Access for the battery room, also for Outback OPTICS dedicated IP
4) Security camera with PTZ for battery room as a visual indicator of what is going on and to see the Outback mate3 screen

Any thoughts:


  • mcgivormcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    What I did with my decommissioned batteries which were still good was dedicate them to water pumping using a bunch of cheap no name equipment except the controller, the batteries see very little load as the array can support the main pump, demand pump is 100w intermittent.To take advantage of the the unused capacity I feed the small inverter output into a auto transfer switch emergency side, since my prime inverter uses more energy overnight than there are loads, I programed an invert block period so loads are transferred to the backup which is on 24/7 anyway.

    Having some sort of backup is useful, nothing worse than attempting repairs in a dark room with a flashlight, the charging points, WiFi and security equipment would be a minor load, water pumping may be an option worth looking into, perhaps emergency perimeter lighting,just a few ideas to ponder.,
    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.
  • richardimorserichardimorse Registered Users Posts: 98 ✭✭
    Each decision opens a new can of worms, so now I am looking at WiFi / Security systems / beams and outdoor issues such as lightning, here I noticed netGear have entered the fray with their Arlo Pro 2 cameras as well as Ubiquity who seem to have a technology gap with low resolution items in the camera and recorder line up, no PTZ and passive POE can't always be everything to everyone.

    My focus area is the battery room, but it is fairly obvious that extending this to outdoor areas for guest utility and security is an option, looks like their isn't a solution in the market that addresses all needs here, but the netgear gets close, I like the battery autonomy in the camera for when power is off so will be looking at their solution more closely which also has alexa integration.

  • Dave AngeliniDave Angelini Solar Expert Posts: 6,226 ✭✭✭✭✭
    I go to offgrid homes all the time with multiple systems. If they want me to be involved, just one system for everything. Spare inverters are fine and even pre-wired but unless there is compelling reason, I mean really compelling, then it all goes.

    Keep it simple offgrid ! Less is more! Build with the best available. Just my opinion.

    You do have AC bypass so what else other than medical is that important.

     If the owners/caretakers are that uninvolved, you will have problems anyway.
    "we go where power lines don't" Sierra Nevada mountain area
    E-mail [email protected]

  • richardimorserichardimorse Registered Users Posts: 98 ✭✭
    Dave has a point, I just got them to recommission a repaired 5KVA Standby generator which has Voltage and Hertz on the low side.  We are running it at 3KVA at the moment to prevent it tripping while we wait for the new generator, the half dead generator is extremely mission critical at the moment.

    Although at the moment the boardwalk lighting, outdoor WiFi and cameras seem like a nice to have addition, they would also become mission critical as soon as they are installed, so putting them on the old batteries (which brings in charging problems) may be a bad idea.  

    What is your opinion on battery bank fusing, personally I like the Red Spot HRC Bakelite fuse carriers with 200A fuses which can also be used as a last resort battery disconnect when sparks are flying in the DC DB board and a safety disconnect when working on the batteries.

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