Battery Bank Fuse Placement

lzhomelzhome Registered Users Posts: 38 ✭✭
I have completed installation of the first phase of solar panels and tomorrow I begin wiring the battery bank. I have seen wiring diagrams and other recommendations but I wanted feedback to avoid any bad decisions. I'm using a 200a fuse on a 24v 310ah battery bank.

Scenario 1: Positive lead >> fuse >> Battery Switch >> positive buss bar >> 2000w Inverter
Scenario 2: Positive lead >> Battery Switch >> fuse >> positive buss bar >>2000w Inverter

With scenario 1 if I need to replace the fuse wouldn't I need to disconnect the cable from the battery first? And scenario 2 I would only need to turn off battery switch to replace fuse.

Which way to go? Or something different?
TriStar MPPT, 8 x 100w PV, MNPV6 Combiner, 4 x 12v 155ah VMAXTanks AGMs and GoPower 2000w PSW Inverter.


  • mcgivormcgivor Solar Expert Posts: 2,419 ✭✭✭✭✭
    edited November 2017 #2
    Electrically it makes no difference, but it is common that the disconnect comes before the fuse, as in a fused disconnect, for safety reasons, mostly involving higher voltages. 
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery bank 
    900W  3 × 300W No name brand Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah FLA 24V nominal as a backup system. 
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergencies and welding.
  • littleharbor2littleharbor2 Solar Expert Posts: 1,108 ✭✭✭✭
    edited November 2017 #3
    These Blue Sea fuses place the fuse at the battery, leaving nothing unprotected.

    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.

  • EstragonEstragon Registered Users Posts: 3,034 ✭✭✭✭✭
    You don't necessarily need to disconnect the battery to change a fuse in scenario 1, or with the bluesea holders. You do need to be careful though. I open breakers to loads and charging sources, and I always wear long rubber gloves, a long plastic jacket, and face shield when working in the battery box.
    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: 28,176 admin
    Another "trick" is to wrap your tools in electrical tape when working on the battery bank (new tape the next time you work on battery bank). Just leave the screwdriver tip/wrench end exposed.

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • lzhomelzhome Registered Users Posts: 38 ✭✭
    Thanks for the replies. Heading to Harbor Freight to get a face shield :)
    TriStar MPPT, 8 x 100w PV, MNPV6 Combiner, 4 x 12v 155ah VMAXTanks AGMs and GoPower 2000w PSW Inverter.
Sign In or Register to comment.