{"product_id":"feb-21700-battery-cell-6500mah-13a-ultra-high-capacity-energy-cell","title":"FEB 21700 Battery Cell – 6500mAh 13A Ultra High Capacity Energy Cell","description":"\u003ch2\u003eFEB 21700 Battery Cell – 6500mAh 13A (Max) Ultra High Capacity Energy Cell\u003c\/h2\u003e\n\n\u003cp\u003e\nThe \u003cstrong\u003eFEB 21700 6500mAh\u003c\/strong\u003e lithium-ion battery cell is designed for applications where \u003cstrong\u003emaximum runtime and energy density\u003c\/strong\u003e are the priority.\n\u003c\/p\u003e\n\n\u003cp\u003e\nThis is one of the highest energy density cylindrical cells available, delivering approximately \u003cstrong\u003e23.4Wh per cell\u003c\/strong\u003e in a compact 21700 format.\n\u003c\/p\u003e\n\n\u003cp\u003e\nBuilt by \u003cstrong\u003eFar East Battery (FEB)\u003c\/strong\u003e, this cell is optimized for efficiency, stability, and long-duration performance rather than extreme current output.\n\u003c\/p\u003e\n\n\u003cp\u003e\nThe FEB 6500mAh cell has also been evaluated in engineering simulation environments, where its voltage behavior, thermal response, and runtime performance are analyzed for real-world applications.\n\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eImportant:\u003c\/strong\u003e This is a \u003cstrong\u003ehigh-capacity energy cell\u003c\/strong\u003e, not a high-discharge power cell.\u003c\/p\u003e\n\n\u003cp\u003eApplications include:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eHigh-capacity battery packs\u003c\/li\u003e\n\u003cli\u003eSolar energy storage systems\u003c\/li\u003e\n\u003cli\u003ePortable power stations\u003c\/li\u003e\n\u003cli\u003eLow to medium current builds\u003c\/li\u003e\n\u003cli\u003eLong-range e-bike builds (multi-parallel configurations)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eTechnical Specifications\u003c\/h2\u003e\n\u003ctable\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eManufacturer\u003c\/td\u003e\n\u003ctd\u003eFEB (Far East Battery)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eModel\u003c\/td\u003e\n\u003ctd\u003e21700G\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCell Type\u003c\/td\u003e\n\u003ctd\u003eLithium-ion rechargeable\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSize\u003c\/td\u003e\n\u003ctd\u003e21700 – 21mm × 70mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNominal Voltage\u003c\/td\u003e\n\u003ctd\u003e3.6V\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNominal Capacity\u003c\/td\u003e\n\u003ctd\u003e6500mAh\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMinimum Capacity\u003c\/td\u003e\n\u003ctd\u003e6350mAh\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNominal Energy\u003c\/td\u003e\n\u003ctd\u003e~23.4Wh\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCharge Voltage\u003c\/td\u003e\n\u003ctd\u003e4.20V (CCCV)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eStandard Discharge\u003c\/td\u003e\n\u003ctd\u003e6.5A (1C)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMaximum Continuous Discharge\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cstrong\u003e13A (Max)\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eVoltage Range\u003c\/td\u003e\n\u003ctd\u003e2.50V – 4.20V\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInternal Resistance\u003c\/td\u003e\n\u003ctd\u003e≤25mΩ\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eEnergy Density\u003c\/td\u003e\n\u003ctd\u003e~312–316 Wh\/kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eUN Classification\u003c\/td\u003e\n\u003ctd\u003eUN3480 – Class 9 Lithium Battery\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eEngineering \u0026amp; Evaluation Use\u003c\/h2\u003e\n\n\u003cp\u003e\nThis cell has been evaluated in engineering simulation environments used for battery design and system development.\n\u003c\/p\u003e\n\n\u003cp\u003e\nWith its high energy density and stable voltage characteristics, it is suitable for modeling real-world performance such as:\n\u003c\/p\u003e\n\n\u003cul\u003e\n\u003cli\u003eTemperature behavior under load\u003c\/li\u003e\n\u003cli\u003eVoltage stability during discharge\u003c\/li\u003e\n\u003cli\u003eRuntime and efficiency in mission profiles\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\nThis highlights the cell’s strength as a \u003cstrong\u003ehigh-energy, long-runtime solution\u003c\/strong\u003e for applications where efficiency and endurance are critical.\n\u003c\/p\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eDIY500AMP Engineering Notes\u003c\/h2\u003e\n\n\u003cp\u003e\nThis is a \u003cstrong\u003epure energy-focused cell\u003c\/strong\u003e. It is designed to deliver maximum capacity, not maximum current.\n\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eReal-world behavior:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eExcellent runtime compared to standard 21700 cells\u003c\/li\u003e\n\u003cli\u003eStable voltage under moderate load\u003c\/li\u003e\n\u003cli\u003eHigher internal resistance compared to power cells\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eBest way to use this cell:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e5A–8A → Ideal performance range\u003c\/li\u003e\n\u003cli\u003e8A–12A → Upper working range\u003c\/li\u003e\n\u003cli\u003e13A → Maximum limit (not recommended for continuous use)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\n\u003cstrong\u003eDIY500AMP Tip:\u003c\/strong\u003e If your goal is runtime and efficiency, this is a solid choice. If your build requires high current, increase your parallel count or choose a high-discharge cell.\n\u003c\/p\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eWhy Buy From DIY500AMP?\u003c\/h2\u003e\n\n\u003cp\u003e\nAt DIY500AMP, we don’t just copy datasheets. We analyze them, test when possible, and translate that information into real-world performance.\n\u003c\/p\u003e\n\n\u003cp\u003e\nMost stores list only the maximum numbers from a datasheet. The problem is those numbers are often achieved under controlled lab conditions and don’t reflect how the cell will behave in an actual battery pack.\n\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eOur approach is different:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eWe list the \u003cstrong\u003emaximum rating based on manufacturer data and test reports\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003eWe also provide \u003cstrong\u003ereal-world recommendations based on experience and testing\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\nThis gives you a much clearer picture of what to expect from the cell in your build.\n\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhy this matters:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eBetter performance in real applications\u003c\/li\u003e\n\u003cli\u003eLower heat and stress on the cells\u003c\/li\u003e\n\u003cli\u003eLonger lifespan and improved reliability\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eOur goal is simple:\u003c\/strong\u003e\u003cbr\u003e\nGive you honest information so you can build better, safer, and more efficient battery packs.\u003c\/p\u003e\n\n\u003cp\u003e\nWhen you buy from DIY500AMP, you are not just buying a battery cell, you are getting guidance based on real-world use.\n\u003c\/p\u003e\n\n\u003chr\u003e\n\n\u003cp\u003e\u003cstrong\u003eSafety Warning for Lithium Ion Battery Usage\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eCustomers should have a clear understanding of lithium ion battery handling and safety before making a purchase. Lithium ion batteries are highly sensitive and may pose fire, burn, or explosion risks if improperly handled. Always charge batteries on fire resistant surfaces, and never leave them charging unattended.\u003c\/p\u003e\n\u003cp\u003eBy purchasing, you assume full responsibility for any injury, damage, or loss arising from the incorrect use or handling of lithium ion batteries or chargers. Compatibility with specific devices is not guaranteed. Only charge using a smart charger designed specifically for this battery type, and do not mix old or used batteries with new ones.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eImportant Usage Guidelines:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003eNot for use in e-cigarettes or similar devices. Lithium ion batteries present a serious risk of injury, property damage, or death if improperly used.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eRisk of fire and explosion. Misuse can cause batteries to ignite, explode, or release harmful gases.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eAlways use in a protected pack. Ensure batteries are used within intended specifications and supported by appropriate circuitry.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eProper storage and handling. Store batteries in protective cases, away from metal items to prevent short circuits.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eInspection prior to use. Do not use batteries with damaged wrappers, torn insulators, or visible damage.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eFollow manufacturer charging specifications. Avoid overcharging or over discharging, and never alter, dismantle, puncture, crush, or burn.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eHeat and water precautions. Do not expose batteries to high temperatures or any liquids.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eAssembly guidelines. Batteries should only be spot welded. Do not solder directly onto battery terminals.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eUsers are expected to have battery handling knowledge before purchasing. By using these batteries, you acknowledge that usage is solely at your own risk, and you take full responsibility for any resulting consequences.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eFor resellers:\u003c\/strong\u003e Please ensure all safety information is passed along to end users to promote safe handling and proper use.\u003c\/p\u003e","brand":"FEB","offers":[{"title":"Default Title","offer_id":42624877330503,"sku":null,"price":8.6,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0588\/8055\/7127\/files\/feb-21700-6500mah-lithium-ion-battery-cell-upright-and-side-view.jpg?v=1774985274","url":"https:\/\/diy500amp.com\/products\/feb-21700-battery-cell-6500mah-13a-ultra-high-capacity-energy-cell","provider":"DIY500AMP.COM","version":"1.0","type":"link"}