Sizing Batteries

czarsczars Registered Users Posts: 16
Does anyone have a suggestion about how to properly size a 48v battery bank for a 4500 grid-tied inverter?


  • BB.BB. Super Moderators, Administrators Posts: 32,814 admin
    Re: Sizing Batteries

    What setup are you asking about? A Xantrex 4.5kW 48 volt Hybrid Inverter setup?

    The normal recommendation would be 450 AH @ 48 volt minimum battery bank to support the maximum charging/load surge currents.

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • czarsczars Registered Users Posts: 16
    Re: Sizing Batteries

    You guessed correctly - Xantrex XW4548. Thanks for your input.
  • Solar GuppySolar Guppy Solar Expert Posts: 1,989 ✭✭✭
    Re: Sizing Batteries

    A common mistake is only sizing for the backup condition.

    The requirement is not only based on what the inverter load ( AC out ) is but what the load to the grid in sell mode can be ( AC in 1 ) as the inverter is bi-directional.

    Which ever is greater load ( selling to the grid OR backup load ) the battery bank minimum needed is 100ah @ 48V nominal bank voltage per kW
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