Charge Wire

Curcuit braker is best, but a simple inline fuse will work.

Being a short run, a fusable link would need to be much smaller gauge than the wire on the output of the alternator. Fusable links operate on internal resistance against the current being drawn by the circuit.

Another note. Fusable link will heat up, so make sure you have a true fusable link cable, they have silicone jacketing and made to melt inside, due to the metals used. They should be designed around a 2 to 3 inch section, not a foot or more. Premade fusable links can be 12 awg for 70Amp to 130Amp rating, for a short length. If you cut a link, your increasing the amount of current capability. A 100 Amp link can be made into a 200 am link by halving it equally.

125% of the rated output is more conservative, most designs are 150% or higher if the peak current can jump. Similar like AC lines, as they are unfiltered/unregulated. But that is with other devices like A/C fan motors with its fusable link.

Driving motorized fans, are best done with fusable links, as they may trip a fuse or breaker by inductance kick back. 125% x the amperage should be fine for a fuse, or breaker. If pushing max current for extended time frames, 150% rating will keep the breaker fresher through its life time. Internally they will run a wee warm if too small for the current rating on extended max current.

Edited by 304-dude - Sep/13/2021 at 2:58pm

One more thing to consider: If your circuit protection triggers for some reason, a fuse can by easily replaced, a breaker can be easily reset, but a fusible link will take time to repair; time you may not have at the track.

The only reason why one would go with a fusable link, is for racing. Depending on its location, in relation to a ground issue during a collision, from metal penetrating the wire or a direct short from alternator damage. Battery power will be much greater and could end up shorting out a circuit breaker. Some have welded closed under a sudden high current condition. A fusable link will fail, guaranteed. Fuses and circuit breakers are very small, and could be bypassed by metal contact within the localized area.


That will give you enough to deturmine what works best for your needs and requirements. All of the above will work, though you will need to figure out which will be safest under vehical damage. It all goes within where you locate and mount, while making the best for isolation.