{"product_id":"sierra-bs11030-battery-switch-1-2-both-off-with-afd-11-bs11030","title":"Sierra BS11030 Battery Switch – 1-2-Both-Off with AFD","description":"\u003ch2\u003eSierra BS11030 Battery Switch – 1-2-Both-Off with Alternator Field Disconnect\u003c\/h2\u003e\u003cp\u003eTake full control of your boat's electrical system with the Sierra BS11030 — a heavy-duty marine battery switch built for 12V to 48V DC systems. The 1-2-Both-Off selector lets you choose between two battery banks, run both simultaneously, or isolate the system entirely. The integrated Alternator Field Disconnect (AFD) protects your alternator from voltage spikes when switching under load — a critical feature for vessels with high-output charging systems.\u003c\/p\u003e\u003cp\u003eHoused in a glass fiber-reinforced nylon enclosure rated IP66 and CE certified, this switch is built to handle the marine environment. Removable windows on all four sides make wiring straightforward, and the ergonomic knob can be removed for an added layer of safety and isolation when the vessel is unattended.\u003c\/p\u003e\u003ch3\u003eKey Specifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eMaximum Voltage: 48V DC\u003c\/li\u003e\n\u003cli\u003eBattery Studs: Tin-plated copper, M8 stud size\u003c\/li\u003e\n\u003cli\u003eStud Torque: 120 lb.-in\u003c\/li\u003e\n\u003cli\u003eRecommended Cable Size: 4\/0 AWG\u003c\/li\u003e\n\u003cli\u003eBattery Inputs: 2\u003c\/li\u003e\n\u003cli\u003eSwitch Function: 1-2-Both-Off (4-position)\u003c\/li\u003e\n\u003cli\u003eEnclosure: Glass fiber-reinforced nylon, IP66 rated\u003c\/li\u003e\n\u003cli\u003eCertifications: CE certified, ISO 8846 \/ SAE J1171 Ignition Protected\u003c\/li\u003e\n\u003cli\u003eMounting: Surface or panel mount\u003c\/li\u003e\n\u003cli\u003eIncludes: (4) M4×35 mounting screws, interchangeable knob labels\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eCompatible Applications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003ePowerboats and center consoles with dual battery banks\u003c\/li\u003e\n\u003cli\u003ePontoon boats and deck boats with 12V–48V electrical systems\u003c\/li\u003e\n\u003cli\u003eVessels with high-output alternators requiring AFD protection\u003c\/li\u003e\n\u003cli\u003eAny marine application requiring ISO 8846 ignition-protected switching\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eParts Desk Insights\u003c\/h3\u003e\u003cp\u003eThe BS11030 is the go-to choice when your vessel has two separate battery banks and a high-output alternator. The built-in AFD circuit prevents alternator damage when switching between banks under load — something a standard battery switch cannot do. If your boat has a single battery bank and no alternator protection requirement, consider the \u003ca href=\"\/products\/sierra-bs11000-battery-disconnect-switch-on-off-48v-ip66-ignition-protected\"\u003eSierra BS11000 On\/Off Disconnect Switch\u003c\/a\u003e instead. For a single-bank setup that still needs AFD, the \u003ca href=\"\/products\/sierra-bs11010-battery-disconnect-switch-on-off-with-alternator-field-disconnect-48v-ip66\"\u003eSierra BS11010 On\/Off with AFD\u003c\/a\u003e is the right fit. If you're running dual banks without an AFD requirement, the \u003ca href=\"\/products\/sierra-bs11020-dual-battery-selector-switch-1-2-both-off-48v-ip66-ignition-protected\"\u003eSierra BS11020 Dual Battery Selector\u003c\/a\u003e covers that application. Pair this switch with a properly rated \u003ca href=\"\/products\/sierra-fs84200-marine-rated-battery-fuse-175a-white\"\u003eSierra Marine Battery Fuse\u003c\/a\u003e on each bank for a complete, code-compliant installation.\u003c\/p\u003e","brand":"LNS","offers":[{"title":"Default Title","offer_id":51250881167396,"sku":"11-BS11030","price":78.49,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0743\/5799\/7604\/files\/11-BS11030.jpg?v=1786511552","url":"https:\/\/marisolmarine.com\/products\/sierra-bs11030-battery-switch-1-2-both-off-with-afd-11-bs11030","provider":"Marisol Marine Company","version":"1.0","type":"link"}