drich5 - Batt. bank fuse sizing

drich5drich5 Registered Users Posts: 7 ✭✭
I have 8 155ah batt. connected in parallel, for a 1240ah total.  What size fuse do I need for adequate protection?  What size wire do I need for charge/load wiring?  What size wire do I need for batt. interconnect wiring?  This is a 12v batt. bank.


  • mike95490mike95490 Solar Expert Posts: 8,967 ✭✭✭✭✭
    edited February 2017 #2
    There are not enough fuses to make 8 parallel batteries safe,     Sorry to be blunt.

    Fuses protect wires.   Wires are rated by the amps they can safely carry,  So the wire size controls the fuse size
    12 ga  20A
    10 ga  30A
      6 ga 55A
    and so on, there are NEC ampacity tables that list the ratings for wires.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

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  • drich5drich5 Registered Users Posts: 7 ✭✭
    Of course, you are right. Thanks for the reminder.
  • littleharbor2littleharbor2 Solar Expert Posts: 1,547 ✭✭✭✭
    If you NEED that much power with a 12 volt bank you should consider 1110 Ah 2 volt batteries.


    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, 700 ah @24 volt AGM battery bank. Plenty of Baja Sea of Cortez sunshine.

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