Battery help

ansio Registered Users Posts: 1

I trying to run one refrigerator, one computer and monitor, 2 led lights. For about 6 hours a day


I have a technical data sheet on the fridge and it says 6.5 amp and 53 Kwh/mo

The lights are 9 watts each so 18

The computer I have no idea yet.


How do I go about gathering the required information and converting it all into useful data to determine what size battery bank I need.




  • littleharbor2
    littleharbor2 Solar Expert Posts: 2,044 ✭✭✭✭✭
    24/7 on the refer? Your specs work out to 1.76 kwh a day, not very efficient. Newer energy efficient fridges are using under 1 kwh a day or less. You don't plan to run the refer for 6 hours a day, do you? If so it will probably run full time trying to get to its desired temp.

    2.1 Kw Suntech 175 mono, Classic 200, Trace SW 4024 ( 15 years old  but brand new out of sealed factory box Jan. 2015), Bogart Tri-metric,  460 Ah. 24 volt LiFePo4 battery bank. Plenty of Baja Sea of Cortez sunshine.

  • Estragon
    Estragon Registered Users Posts: 4,496 ✭✭✭✭✭
    Is this for a backup situation in which you expect outages of about 6 hours and then restoration of grid power? If so, is this expected to happen every day?

    Do you have a generator, and if so what kind and size?

    Is the computer a laptop or desktop, and how old is it?
    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
  • BB.
    BB. Super Moderators, Administrators Posts: 33,439 admin
    Sounds like for a location where afternoon power shortages are common.

    Ideally, you would want a Kill-a-Watt type power meter so you can measure your real loads: (120 VAC) (UK/Europe 240 VAC version)

    Ideally, your battery bank should be around 2-6 times your daily loads (~4x is probably a good cost effective setup--basically, 2 days of stored energy and 50% maximum discharge).


    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset