{"product_id":"stinger-sgp35-12v-high-current-battery-relay-isolator-500a-continuous-water-resistant-for-marine-car-audio","title":"STINGER SGP35 12V High-Current Battery Relay \u0026 Isolator — 500A Continuous, Water-Resistant for Marine \u0026 Car Audio","description":"\u003cp\u003e\u003cstrong\u003eThe STINGER SGP35 is a water-resistant 12V high-current battery relay and isolator that safely combines charging while isolating batteries, rated for 500A continuous with 900A surge capacity.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eDesigned for automotive, marine and powersports systems, the SGP35 provides a robust way to add a secondary battery or protect a primary battery from accessory drain. Built from phenolic plastic to resist moisture and corrosion, this relay switches with your ignition to allow charging while keeping battery circuits separate when the engine is off. Its long mechanical life and high current limits make it suitable for high-demand car audio, winches, auxiliary lighting and off-grid accessory setups.\u003c\/p\u003e\n\n\u003ch3\u003eHow does the SGP35 prevent my primary battery from draining?\u003c\/h3\u003e\n\u003cp\u003eThe SGP35 acts as an automatic isolator: it closes only when the ignition is on, linking the starter battery and auxiliary battery for charging. When the engine is off, the relay opens to leave batteries electrically separate, preventing accessory load from drawing down the starter battery.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eAutomatic ignition-activated switching for hands-free operation\u003c\/li\u003e\n  \u003cli\u003eIsolates batteries when ignition is off to protect starter power\u003c\/li\u003e\n  \u003cli\u003eCompatible with simple trigger wiring—no complex control modules required\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWill this relay handle high-current car audio or winch loads?\u003c\/h3\u003e\n\u003cp\u003eYes—the SGP35 is engineered for demanding loads. It supports continuous currents up to 500 amps and tolerates short surge events up to 900 amps, giving headroom for powerful amplifiers, winches and heavy-duty accessories.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003e500A continuous rating for sustained accessory draw\u003c\/li\u003e\n  \u003cli\u003e900A surge handling for brief inrush currents from amplifiers or motors\u003c\/li\u003e\n  \u003cli\u003eSolid contact construction for efficient high-current transfer\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eIs the SGP35 suitable for marine and off-road use?\u003c\/h3\u003e\n\u003cp\u003eYes—the housing is made from water-resistant phenolic plastic to resist moisture and corrosion common in marine and powersports environments. Its sealed design and durable construction make it a reliable choice for exposed installations.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eWater-resistant body protects internal contacts from humidity and spray\u003c\/li\u003e\n  \u003cli\u003eRobust build rated for 100,000 mechanical cycles for long service life\u003c\/li\u003e\n  \u003cli\u003eWorks with all 12V alternator and charging system types\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eHow do I install and wire the SGP35 with my alternator and batteries?\u003c\/h3\u003e\n\u003cp\u003eInstallation is straightforward: mount the relay in a dry, accessible location, run heavy gauge battery cables to the main contact studs, and connect an ignition-switched trigger wire to activate the coil. Use appropriately sized wiring and fusing for the current you expect to carry.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eMount on a solid surface with adequate ventilation and access\u003c\/li\u003e\n  \u003cli\u003eUse heavy-gauge battery cables and proper ANL or inline fuses\u003c\/li\u003e\n  \u003cli\u003eConnect a switched 12V trigger to operate the relay with ignition\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eWho is this for? The STINGER SGP35 is made for vehicle owners and installers who need dependable battery isolation and high-current capability: car audio enthusiasts running big amplifiers, boat owners protecting starter batteries, off-roaders using winches and accessory banks, and anyone adding a secondary battery to a 12V charging system. It’s especially useful where moisture resistance and long mechanical life are required, and for systems that demand quick, automatic switching without complex electronics.\u003c\/p\u003e\n\u003csection class=\"product-faq-snippet\"\u003e\u003ch3\u003eFAQ\u003c\/h3\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Can the SGP35 work with any 12V alternator?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Yes. The SGP35 is compatible with all standard 12V alternators and charging systems.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Do I need a special fuse for this relay?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Use heavy-gauge battery cables and an appropriately rated battery fuse or ANL between batteries based on your expected continuous current.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/section\u003e","brand":"STINGER","offers":[{"title":"Default Title","offer_id":48082748932254,"sku":"B004WDPZEW","price":155.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0781\/2041\/9486\/files\/stinger-front-view-relay.jpg?v=1785813020","url":"https:\/\/northtrailauto.ca\/products\/stinger-sgp35-12v-high-current-battery-relay-isolator-500a-continuous-water-resistant-for-marine-car-audio","provider":"North Trail Auto","version":"1.0","type":"link"}