Every electrical system in every CAT6 Cable, and every battery needs battery wire. As you likely know, marine battery wire is unique and not the same as the battery wire used on land. What most people don\u2019t know, however, is what actually makes those cables different. This guide will help you keep an eye out for the most important factors for your next battery wire purchase.1. InsulationInsulation is possibly the most important part of any marine wire. In fact, there are extensive certifications and rules put in place by the Society of Automotive Engineers that determine what types of wire insulation is ideal for use on the water, both at sea and in fresh water. The Society of Automotive Engineers (SAE) is the world\u2019s largest automotive engineer association, and most quality wires will list any certifications they have received from the SAE right on the packaging or within the product documentation.Insulation cannot be overlooked when choosing marine battery wire. Moisture is a surety on the water, no matter how well your battery compartment is sealed. Make sure to get wires with SAE certifications.2. Tinned CopperThe \u201ctinning\u201d of wires refer to a process by which manufacturers coat the copper strands that make up a wire with tin, a slightly less conductive but more resilient metal. This results in a thin protective layer between a wire\u2019s insulation and the copper itself. Tinned copper wires are highly resistant to corrosion and moisture, and as a result are ideal for use on the water. Most certified cables sold for marine use are going to be tinned copper wire, and, in nearly all circumstances, tinned copper wires are going to be ideal for your battery.3. High Strand CountBecause of the high-grade insulation used for certified marine battery wire, most wires for marine batteries are lacking in flexibility. To offset this lack of flexibility, it is important to invest in wires that have high strand counts. A high strand count means that a wire has a greater number of copper strands that make up the \u201cbraid\u201d of the wire. The greater the number of strands, the finer the strands, which contributes to a cable being considerably more flexible.4. GaugeThe gauge of a battery wire, in combination with its length, determines how much of an electrical current it can carry to the rest of the system. While determining the appropriate wire gauge for your system can be as easy as consulting the owner\u2019s manual or inspecting the wires you already have, it is still important to keep gauge size in mind. Considering wire gauge is especially important if you are making improvements to your system that will involve more devices or different batteries. Unfortunately, wires are not one-size-fits-all.5. LengthAs mentioned above, length is another piece of the equation that determines how much current your wires can carry. Most battery wire upgrades in marine systems will not add or subtract enough length to affect the current-carrying capacity of a wire, however, certain changes may indeed affect this, so it is important to keep length in mind when selecting a wire. In addition, it is important to carefully measure the spaces you will be placing your wires in before you buy, including looking for potential obstacles that would require more wire than you might have initially assumed. Buying a wire only to have it not be long enough can be a frustrating and expensive endeavor.