Lithium upgrade in travel trailer.

[peanut]

I will be replacing the lead acid battery with a 100 amp hour lithium battery. I plan to use 4 gauge wire to run less than 6 feet from the battery to the “electric box”. I what size fuse do I need between the battery positive And the power cut off switch? How does one chose between MIDI®/AMI®, MRBF, MEGA®/AMG®, and ANL fuses?

[SunEagle]

I will be replacing the lead acid battery with a 100 amp hour lithium battery. I plan to use 4 gauge wire to run less than 6 feet from the battery to the “electric box”. I what size fuse do I need between the battery positive And the power cut off switch? How does one chose between MIDI®/AMI®, MRBF, MEGA®/AMG®, and ANL fuses?

Remember that fusing sizes are made based on the amp rating of the wire. So if you are going to use a 4 gauge copper wire then you should follow the NEC ratings of that size and insulation type. (which could be type THHN and 95 amps or different values for different insulation types)

As for the type of fuse needed, again that will depend on the fuse holder being used along with the voltage rating on the wire.

[chrisski]

For a lithium battery, they have such high AIC, you want to go with a class T fuse. Otherwise, the fuse could blow and arcs across it keeping the short going.

In addition to not exceeding the amp rating for the wire with the fuse, what is the wattage you’re running on this battery?