Forum Discussion

1L243's avatar
1L243
Explorer II
May 17, 2022

Catastrophic Fuse

I have had my Solar setup for almost a year now. 500 watts on the roof (maybe more in the future), 2000 watt inverter, 340ah lead acid battery bank. The largest amperage items I run are my microwave and drip coffee maker. Everything works as it should

I installed a 250amp ANL fuse 5 feet from the batteries before the inverter or positive fuse block.

I am using 2.0 cable for the jumpers between the batteries and 4.0 cable to the inverter and positive fuse block.

I did not install a Catastrophic fuse at the primary positive battery terminal. Should I? And Why?
  • time2roll's avatar
    time2roll
    Nomad
    May 17, 2022
    The fuse was apparently installed at the wrong end of the battery cable. Swap that fuse and cable end to end. The risk is a short to ground at some point along that 5' connection.
  • pianotuna's avatar
    pianotuna
    Nomad III
    May 17, 2022
    Catastrophic failure fuse always at the battery post (I chose positive).

    Why? Because they used to use batteries to weld. 1200 watts of energy being dumped in a second is enough for a quite nice fire and just for good measure the battery may explode. A fine thing to have hot acid all over.

    This is an IMPORTANT and easy fix. I would make the change asap.
  • Skibane's avatar
    Skibane
    Explorer II
    May 17, 2022
    time2roll wrote:
    The fuse was apparently installed at the wrong end of the battery cable. Swap that fuse and cable end to end. The risk is a short to ground at some point along that 5' connection.


    Yep.

    With the fuse located right at the battery post, all of the cable beyond that point is protected.
  • theoldwizard1's avatar
    theoldwizard1
    Explorer II
    May 18, 2022
    time2roll wrote:
    The fuse was apparently installed at the wrong end of the battery cable. Swap that fuse and cable end to end. The risk is a short to ground at some point along that 5' connection.

    Like time2roll said, the fuse should always be as close as possible to the battery.

    Why different size wire ? Stick with one size. There are people on eBay that will custom make battery cables. You choose the wire size, color, type if end and length.
  • 2oldman's avatar
    2oldman
    Explorer II
    May 18, 2022
    Since DC travels from - to +, I would think the fuse should be on the battery -
  • Bobbo's avatar
    Bobbo
    Explorer II
    May 18, 2022
    theoldwizard1 wrote:
    Why different size wire ? Stick with one size. There are people on eBay that will custom make battery cables. You choose the wire size, color, type if end and length.

    https://www.customcableusa.com/

    (Used to be called Genuinedealz.com)

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