In this photo we can see the battery bank and the red 2/0 wire feeding the Class-T fuse holder. At a bare minimum you want to be using Class-T fuses as your main bank protection for an LFP bank. This bank can easily throw 20,000A or more of current into a dead short and can damage and literally blow windows out of ANL fuses. I had this happen during the testing of some ANL fuses sent to me by a DIY LFP guy from Cruisers Forum, Thanks Bob!!! Class-T fuses are fully metal encased and are a very safe fuse.


All fuses have what is called an AIC rating or amperage interrupt capacity rating. This is the rating at which the fuse will fail safely. Class-T Fuses have the highest AIC rating of any fuse we use in the marine environment. There are fuses out there with higher AIC ratings but none of them have fuse holders avaible that are suitable for a marine application.


Ideally the main bank over current protection needs to be within 7" of the battery bank but as we can see here that is often impossible. D'oh!!! There is technically more than 7" of wire to get from the + battery post to the Class-T fuse here. Is this an unsafe installation, hell no, but sometimes the standards are a little to broad brushed to apply realistically to the real world so we do the best we can...