{"product_id":"4-awg-battery-cable-21mm2","title":"4 AWG Battery Cables (21mm²)","description":"\u003cdiv class=\"sapphire-product-description\"\u003e\n\u003ch2\u003e4 AWG Battery Cable with Ring Terminals\u003c\/h2\u003e\n\u003chr class=\"sapphire-hr\"\u003e\n\u003cp\u003eBuild clean, dependable high-current connections with a ready-to-install \u003cstrong\u003e4 AWG battery cable\u003c\/strong\u003e. Each cable uses a heavy-duty \u003cstrong\u003e21 mm² ultra-fine-strand oxygen-free copper (OFC) conductor\u003c\/strong\u003e with a durable PVC jacket and tinned copper ring terminals installed on each end.\u003c\/p\u003e\n\u003cp\u003eChoose the colour, cable length and lug size required for your installation. These cables are well suited to batteries, inverters, busbars, disconnect switches, fuse holders and other high-current DC equipment.\u003c\/p\u003e\n\u003cdiv class=\"sapphire-callout sapphire-callout-yellow\"\u003e\n\u003cdiv class=\"sapphire-callout-title\"\u003eSold Individually\u003c\/div\u003e\n\u003cp class=\"callout-p\"\u003eEach quantity includes \u003cstrong\u003eone cable\u003c\/strong\u003e in the selected colour, length and lug size. Order one red and one black cable if you need a conventional positive-and-negative cable pair.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003ch3 class=\"sapphire-section-title\"\u003eWhy You’ll Love It\u003c\/h3\u003e\n\u003chr class=\"sapphire-hr\"\u003e\n\u003cul class=\"sapphire-checklist\"\u003e\n\u003cli\u003e\n\u003cstrong\u003eReady to install\u003c\/strong\u003e — ring terminals are already fitted to both ends\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHeavy-duty 21 mm² OFC conductor\u003c\/strong\u003e — closely matches standard 4 AWG\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUltra-fine-strand construction\u003c\/strong\u003e — flexible and easier to route through tight installations\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eChoose your length\u003c\/strong\u003e — get precisely what you want\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eM8 lug terminals\u003c\/strong\u003e — sized for common 5\/16″ battery, fuse holder and busbar studs\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRed or black jacket\u003c\/strong\u003e — clearly identify positive and negative wiring\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIndividual cable ordering\u003c\/strong\u003e — purchase only the \u003cstrong\u003eexact\u003c\/strong\u003e cables you need\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cdiv class=\"sapphire-callout sapphire-callout-blue\"\u003e\n\u003cdiv class=\"sapphire-callout-title\"\u003eCheck Both Connection Points\u003c\/div\u003e\n\u003cp class=\"callout-p\"\u003eThe stocked cables in this listing have \u003cstrong\u003eM8 lugs on both ends\u003c\/strong\u003e. M8 fits an approximately 5\/16″ stud. Need M10 or different lug sizes at each end? Contact us about another configuration.\u003c\/p\u003e\n\u003cdiv class=\"sapphire-cta-group\"\u003e\u003ca class=\"sapphire-cta\" href=\"https:\/\/sapphirebattery.ca\/pages\/contact\" rel=\"noopener\" target=\"_blank\"\u003eRequest a Different Configuration\u003c\/a\u003e\u003c\/div\u003e\n\u003c\/div\u003e\n\u003ch3 class=\"sapphire-section-title\"\u003eSuggested Applications\u003c\/h3\u003e\n\u003chr class=\"sapphire-hr\"\u003e\n\u003cul class=\"sapphire-checklist\"\u003e\n\u003cli\u003eBattery-to-inverter connections\u003c\/li\u003e\n\u003cli\u003eBattery-to-busbar connections\u003c\/li\u003e\n\u003cli\u003eBattery disconnect switches\u003c\/li\u003e\n\u003cli\u003eClass T, ANL and MEGA fuse holders\u003c\/li\u003e\n\u003cli\u003eShort high-current equipment jumpers\u003c\/li\u003e\n\u003cli\u003eBattery-bank series or parallel interconnections\u003c\/li\u003e\n\u003cli\u003eRV, van, marine and off-grid electrical systems\u003c\/li\u003e\n\u003cli\u003eBackup power and mobile equipment installations\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3 class=\"sapphire-section-title\"\u003eSpecifications\u003c\/h3\u003e\n\u003chr class=\"sapphire-hr\"\u003e\n\u003ctable class=\"sapphire-spec-table\"\u003e\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eNominal Cable Size\u003c\/th\u003e\n\u003ctd\u003e21 mm²\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eApproximate AWG Equivalent\u003c\/th\u003e\n\u003ctd\u003e4 AWG\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eConductor Material\u003c\/th\u003e\n\u003ctd\u003eOxygen-free copper (OFC \/ pure copper)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eStranding\u003c\/th\u003e\n\u003ctd\u003eUltra-fine strand\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eInsulation\u003c\/th\u003e\n\u003ctd\u003ePVC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eLug Material\u003c\/th\u003e\n\u003ctd\u003eTinned copper\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eLug Options\u003c\/th\u003e\n\u003ctd\u003eM8 (5\/16″)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\u003c\/table\u003e\n\u003cdiv class=\"sapphire-callout sapphire-callout-yellow\"\u003e\n\u003cdiv class=\"sapphire-callout-title\"\u003eProtect the Cable with a Fuse\u003c\/div\u003e\n\u003cp class=\"callout-p\"\u003eA positive cable connected to a battery should normally be protected by an appropriately rated DC fuse installed as close to the battery as practical. The correct fuse type and rating depend on the cable application, connected equipment and available battery fault current.\u003c\/p\u003e\n\u003cdiv class=\"sapphire-cta-group\"\u003e\u003ca class=\"sapphire-cta\" href=\"https:\/\/sapphirebattery.ca\/collections\/fuses-circuit-protection\" rel=\"noopener\" target=\"_blank\"\u003eShop Fuses \u0026amp; Circuit Protection\u003c\/a\u003e\u003c\/div\u003e\n\u003c\/div\u003e\n\u003ch3 class=\"sapphire-section-title\"\u003eWhat’s Included\u003c\/h3\u003e\n\u003chr class=\"sapphire-hr\"\u003e\n\u003cul class=\"sapphire-checklist\"\u003e\u003cli\u003e1 × 4 AWG \/ 21 mm² battery cable at your selected length and colour\u003c\/li\u003e\u003c\/ul\u003e\n\u003ch3 class=\"sapphire-section-title\"\u003eFrequently Asked\u003c\/h3\u003e\n\u003chr class=\"sapphire-hr\"\u003e\n\u003cdetails class=\"sapphire-faq-item\"\u003e\u003csummary\u003eIs this listing for one cable or a red-and-black pair?\u003c\/summary\u003e\u003cp class=\"sapphire-faq-p\"\u003eThis listing is for \u003cstrong\u003eone individual cable\u003c\/strong\u003e. Select red or black when ordering. Add one of each colour to your cart if you need a conventional positive-and-negative pair.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails class=\"sapphire-faq-item\"\u003e\u003csummary\u003eIs 21 mm² exactly the same as 4 AWG?\u003c\/summary\u003e\u003cp class=\"sapphire-faq-p\"\u003eThey are effectively equivalent for product selection. Standard 4 AWG has a conductor area of approximately 21.2 mm², while this cable is specified as 21 mm².\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails class=\"sapphire-faq-item\"\u003e\u003csummary\u003eWhat is OFC cable?\u003c\/summary\u003e\u003cp class=\"sapphire-faq-p\"\u003eOFC stands for oxygen-free copper. It is pure copper cable rather than copper-clad aluminum, providing excellent conductivity for high-current battery and inverter connections.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails class=\"sapphire-faq-item\"\u003e\u003csummary\u003eWhat does ultra-fine strand mean?\u003c\/summary\u003e\u003cp class=\"sapphire-faq-p\"\u003eInstead of using a small number of thick copper strands, the conductor is made from many very fine strands. This makes the cable more flexible and easier to route around batteries, inverters, fuse holders and other equipment.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails class=\"sapphire-faq-item\"\u003e\u003csummary\u003eHow do I choose the lug size?\u003c\/summary\u003e\u003cp class=\"sapphire-faq-p\"\u003eThe stocked 4 AWG \/ 21 mm² cables use M8 lugs on both ends. M8 is approximately 5\/16″. Contact us if you require M10 or mixed lug sizes.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails class=\"sapphire-faq-item\"\u003e\u003csummary\u003eDo both ends have the same lug size?\u003c\/summary\u003e\u003cp class=\"sapphire-faq-p\"\u003eYes. The stocked cables in this listing use M8 lugs on both ends. Contact us if you require M10 or different lug sizes at each end.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails class=\"sapphire-faq-item\"\u003e\u003csummary\u003eWhy is only M8 currently listed?\u003c\/summary\u003e\u003cp class=\"sapphire-faq-p\"\u003eThe stocked 4 AWG \/ 21 mm² assortment currently uses M8 lugs in 15, 30, 60 and 90 cm lengths. Contact us if you need an M10 or mixed-lug cable.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails class=\"sapphire-faq-item\"\u003e\u003csummary\u003eAre red and black cables electrically different?\u003c\/summary\u003e\u003cp class=\"sapphire-faq-p\"\u003eNo. Cables with the same conductor size, length and lug configuration are electrically equivalent. The jacket colour is used to identify polarity and make the installation easier to inspect and service.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails class=\"sapphire-faq-item\"\u003e\u003csummary\u003eCan I use this cable with a lithium battery?\u003c\/summary\u003e\u003cp class=\"sapphire-faq-p\"\u003eYes, provided 4 AWG \/ 21 mm² cable is appropriately sized for the system current, circuit length and installation conditions. These cables can also be used with other battery chemistries when properly selected and protected.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails class=\"sapphire-faq-item\"\u003e\u003csummary\u003eWhat size inverter can I connect with 4 AWG cable?\u003c\/summary\u003e\u003cp class=\"sapphire-faq-p\"\u003eCable suitability cannot be determined from inverter wattage alone. Battery voltage, maximum DC current, total positive-and-negative circuit length, ambient temperature and installation method must all be considered. Follow the inverter manufacturer’s cable and fuse requirements.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails class=\"sapphire-faq-item\"\u003e\u003csummary\u003eDo I need a fuse?\u003c\/summary\u003e\u003cp class=\"sapphire-faq-p\"\u003eUsually yes. Positive battery wiring should normally be protected by a properly selected DC fuse located close to the battery. The fuse is intended to protect the cable if a short circuit occurs. Always verify the required fuse type and rating for your equipment and battery system.\u003c\/p\u003e\n\u003cdiv class=\"sapphire-cta-group\"\u003e\u003ca class=\"sapphire-cta\" href=\"https:\/\/sapphirebattery.ca\/collections\/fuses-circuit-protection\" rel=\"noopener\" target=\"_blank\"\u003eBrowse Circuit Protection\u003c\/a\u003e\u003c\/div\u003e\u003c\/details\u003e\n\u003cdetails class=\"sapphire-faq-item\"\u003e\u003csummary\u003eCan you supply a custom length or mixed lug configuration?\u003c\/summary\u003e\u003cp class=\"sapphire-faq-p\"\u003eYes. Sapphire Energy can build other cable lengths and lug combinations. Include the required cable size, finished length, colour and lug size for each end when contacting us.\u003c\/p\u003e\n\u003cdiv class=\"sapphire-cta-group\"\u003e\u003ca class=\"sapphire-cta\" href=\"https:\/\/sapphirebattery.ca\/pages\/contact\" rel=\"noopener\" target=\"_blank\"\u003eContact Us\u003c\/a\u003e\u003c\/div\u003e\u003c\/details\u003e\n\u003cdiv class=\"sapphire-callout sapphire-callout-blue\"\u003e\n\u003cdiv class=\"sapphire-callout-title\"\u003eNeed Help Choosing Your Battery Cables?\u003c\/div\u003e\n\u003cp class=\"callout-p\"\u003eTell us your battery voltage, equipment model, maximum current, required cable length and connection stud sizes. We can help you select suitable cable and fuse protection for the installation.\u003c\/p\u003e\n\u003cdiv class=\"sapphire-cta-group\"\u003e\u003ca class=\"sapphire-cta\" href=\"https:\/\/sapphirebattery.ca\/pages\/contact\" rel=\"noopener\" target=\"_blank\"\u003eContact Sapphire Energy\u003c\/a\u003e\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e","brand":"Sapphire Energy","offers":[{"title":"Red \/ 6\" (15cm) \/ M8 (5\/16\")","offer_id":55269261082943,"sku":"CBL-21-M8-015RD","price":8.95,"currency_code":"CAD","in_stock":true},{"title":"Red \/ 12\" (30cm) \/ M8 (5\/16\")","offer_id":55269261115711,"sku":"CBL-21-M8-030RD","price":11.95,"currency_code":"CAD","in_stock":true},{"title":"Red \/ 24\" (60cm) \/ M8 (5\/16\")","offer_id":55269261148479,"sku":"CBL-21-M8-060RD","price":17.95,"currency_code":"CAD","in_stock":true},{"title":"Red \/ 36\" (90cm) \/ M8 (5\/16\")","offer_id":55269261181247,"sku":"CBL-21-M8-090RD","price":22.95,"currency_code":"CAD","in_stock":true},{"title":"Black \/ 6\" (15cm) \/ M8 (5\/16\")","offer_id":55269261214015,"sku":"CBL-21-M8-015BK","price":8.95,"currency_code":"CAD","in_stock":true},{"title":"Black \/ 12\" (30cm) \/ M8 (5\/16\")","offer_id":55269261246783,"sku":"CBL-21-M8-030BK","price":11.95,"currency_code":"CAD","in_stock":true},{"title":"Black \/ 24\" (60cm) \/ M8 (5\/16\")","offer_id":55269261279551,"sku":"CBL-21-M8-060BK","price":17.95,"currency_code":"CAD","in_stock":true},{"title":"Black \/ 36\" (90cm) \/ M8 (5\/16\")","offer_id":55269261312319,"sku":"CBL-21-M8-090BK","price":22.95,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0914\/6803\/8463\/files\/Dual_Battery_cable_red_black_lugs_1254px.webp?v=1788376434","url":"https:\/\/sapphirebattery.ca\/products\/4-awg-battery-cable-21mm2","provider":"Sapphire Energy","version":"1.0","type":"link"}