{"product_id":"fenix-button-top-21700-5000mah-rechargeable-battery-type-c-input-output-protection-circuit-built-in-large-capacity-3-6v-replacement-battery-for-flashlight-headlamps-etc","title":"Fenix ARB-L21-5000U 21700 5000mAh USB-C Rechargeable Battery Button Top – Protected Cell with Power Bank Output for Flashlights \u0026 Headlamps","description":"\u003ch4\u003e\u003cspan class=\"\"\u003eDescription\u003c\/span\u003e\u003c\/h4\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cspan class=\"\"\u003eThe Fenix ARB-L21-5000U is a revolutionary 21700 battery that combines massive 5000mAh capacity with a built-in USB-C charging and discharging port. Unlike ordinary rechargeable cells, it can act as an emergency power bank to charge your phone, headlamp, or other USB devices directly—no separate charger required for the battery itself, and no separate power bank needed in a pinch. The integrated protection circuit guards against overcharge, over-discharge, and short circuits, while the button top design ensures broad compatibility with 21700 flashlights. With 5000mAh of energy and dual-role versatility, it is the ultimate all-in-one power solution for outdoor adventures, travel, and emergency preparedness.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch4\u003e\u003cspan class=\"\"\u003eKey Features\u003c\/span\u003e\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003e5000mAh High Capacity\u003c\/span\u003e\u003c\/strong\u003e\u003cspan class=\"\"\u003e – One of the highest capacities in the 21700 form factor, providing exceptionally long runtime for high-output LED flashlights and headlamps.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eBuilt-in USB-C Two-Way Charging\u003c\/span\u003e\u003c\/strong\u003e\u003cspan class=\"\"\u003e – Input: Recharge the battery from any USB-C source (wall adapter, power bank, car charger). Output: Use the battery as an emergency power bank to charge your phone, GPS, or other small devices.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eIntegrated Safety Protection\u003c\/span\u003e\u003c\/strong\u003e\u003cspan class=\"\"\u003e – Built-in circuit prevents overcharge, over-discharge, short circuits, and overcurrent, ensuring safe, worry-free operation.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eButton Top Design\u003c\/span\u003e\u003c\/strong\u003e\u003cspan class=\"\"\u003e – Raised positive terminal ensures reliable contact in Fenix and most other 21700 flashlights and devices.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eLED Power Indicator\u003c\/span\u003e\u003c\/strong\u003e\u003cspan class=\"\"\u003e – Built-in LED shows remaining power level and charging status, so you always know when to recharge.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eGenuine Fenix Quality\u003c\/span\u003e\u003c\/strong\u003e\u003cspan class=\"\"\u003e – Premium 21700 cell core with rigorous manufacturing standards for consistent performance and long service life.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003e\u003cspan class=\"\"\u003eParameters\u003c\/span\u003e\u003c\/h4\u003e\n\u003cdiv class=\"ds-scroll-area ds-scroll-area--show-on-focus-within ds-scroll-area--enabled _1210dd7 c03cafe9\"\u003e\n\u003cdiv class=\"ds-scroll-area__gutters\"\u003e\n\u003cdiv class=\"ds-scroll-area__horizontal-gutter\"\u003e\u003c\/div\u003e\n\u003cdiv class=\"ds-scroll-area__vertical-gutter\"\u003e\u003c\/div\u003e\n\u003c\/div\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003e\u003cspan class=\"\"\u003eParameter\u003c\/span\u003e\u003c\/th\u003e\n\u003cth\u003e\u003cspan class=\"\"\u003eSpecification\u003c\/span\u003e\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003cbr\u003e\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003eModel\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003eFenix ARB-L21-5000U\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003eType\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003e21700 Button Top Protected Battery with USB-C Power Bank Output\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003eTypical Capacity\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003e5000 mAh (0.2C discharge to 2.5V)\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003eNominal Voltage\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003e3.6 V (typical operating 3.7 V)\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003eMax Continuous Discharge\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\n\u003cstrong\u003e\u003cspan class=\"\"\u003e~8 A\u003c\/span\u003e\u003c\/strong\u003e\u003cspan class=\"\"\u003e (limited by built-in protection circuit)\u003c\/span\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003eProtection Functions\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003eOvercharge, Over-discharge, Short Circuit, Overcurrent\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003eUSB-C Input (Charging)\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003e5V \/ 1–2A\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003eUSB-C Output (Power Bank)\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003e5V \/ 1–2A (supports charging small USB devices like phones, GPS, headlamps)\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003eDischarge Cut-off Voltage\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003e2.5 V (automatic protection cutoff)\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003eCycle Life\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003e≥ 500 cycles (to 80% capacity)\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003eOperating Temperature\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003e-20°C to 60°C (discharge); 0°C to 45°C (charge)\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003eTop Type\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003eButton Top\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003eDimensions\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003eApprox. 21.5 mm diameter × 76 mm length (~6mm longer than standard unprotected 21700)\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003eWeight\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003eApprox. 73 g\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003ePackage Includes\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003e1 × Fenix ARB-L21-5000U USB-C rechargeable battery\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003cbr\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003ch4\u003e\u003cspan class=\"\"\u003eApplications\u003c\/span\u003e\u003c\/h4\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eRecommended For\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eHigh-Output 21700 LED Flashlights\u003c\/span\u003e\u003c\/strong\u003e\u003cspan class=\"\"\u003e – Perfect for Fenix and other 21700-powered flashlights. The 5000mAh capacity ensures extremely long illumination time, while USB-C charging allows convenient recharging anywhere.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eHeadlamps (21700 Compatible)\u003c\/span\u003e\u003c\/strong\u003e\u003cspan class=\"\"\u003e – Extended runtime for professional, industrial, or outdoor use. The protection circuit prevents over-discharge damage.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eEmergency Power Bank Use\u003c\/span\u003e\u003c\/strong\u003e\u003cspan class=\"\"\u003e – In a pinch, use the battery to charge your phone, GPS device, or secondary headlamp directly via USB-C cable. An essential backup for outdoor adventures and emergencies.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eCamping Lanterns \u0026amp; Outdoor Gear\u003c\/span\u003e\u003c\/strong\u003e\u003cspan class=\"\"\u003e – Massive capacity keeps your campsite illuminated all night, with the added bonus of emergency device charging.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eTravel \u0026amp; Everyday Carry\u003c\/span\u003e\u003c\/strong\u003e\u003cspan class=\"\"\u003e – One device serves as both a flashlight battery and a backup power bank, reducing the gear you need to carry.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eNot Recommended For\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eHigh-Drain Vaping \/ Mechanical Mods\u003c\/span\u003e\u003c\/strong\u003e\u003cspan class=\"\"\u003e – Requires 15–35A unprotected cells. The protection circuit limits output to ~8A.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eCordless Power Tools\u003c\/span\u003e\u003c\/strong\u003e\u003cspan class=\"\"\u003e – Require 20–40A continuous current.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eDevices Requiring Flat Top 21700 Cells\u003c\/span\u003e\u003c\/strong\u003e\u003cspan class=\"\"\u003e – This is a button top cell. Verify compatibility.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eUltra-Compact Flashlights\u003c\/span\u003e\u003c\/strong\u003e\u003cspan class=\"\"\u003e – The built-in USB-C port and protection circuit increase length to ~76mm. Ensure your device can accommodate this before purchasing.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003e\u003cspan class=\"\"\u003eFAQ\u003c\/span\u003e\u003c\/h4\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eQ: Can this battery really charge my phone?\u003c\/span\u003e\u003c\/strong\u003e\n\u003cbr\u003e\u003cspan class=\"\"\u003eA: Yes. The ARB-L21-5000U features a two-way USB-C port. When connected to a USB device, it can output power to charge phones, GPS units, secondary headlamps, and other small USB-powered gadgets. Note that the output is 5V\/1–2A, providing emergency top-up power. It is not intended to replace a dedicated high-capacity power bank for full daily phone charging.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eQ: How do I charge this battery?\u003c\/span\u003e\u003c\/strong\u003e\n\u003cbr\u003e\u003cspan class=\"\"\u003eA: Use any standard USB-C cable connected to a 5V USB power source (phone charger, power bank, laptop, or car adapter). The built-in LED indicator shows the charge status. A full charge takes several hours depending on the power source.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eQ: Will this fit my 21700 flashlight?\u003c\/span\u003e\u003c\/strong\u003e\n\u003cbr\u003e\u003cspan class=\"\"\u003eA: It fits most 21700 flashlights that accept button top cells. Due to the integrated USB-C port and protection circuit, this battery is approximately 76mm long—about 6mm longer than a standard unprotected 21700 (70mm). Some compact flashlights with tight battery compartments may not close completely. Please check your device’s battery tube length before ordering.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eQ: Is this battery suitable for vaping or power tools?\u003c\/span\u003e\u003c\/strong\u003e\n\u003cbr\u003e\u003cspan class=\"\"\u003eA: No. Vaping devices and power tools require high continuous currents (15–40A). The ARB-L21-5000U’s protection circuit limits output to approximately 8A. For those applications, use dedicated high-drain unprotected cells.\u003c\/span\u003e\u003c\/p\u003e","brand":"Fenix","offers":[{"title":"Default Title","offer_id":51454155784438,"sku":"OAS412","price":31.98,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0819\/2753\/6886\/files\/imagesfenix-21700-5000mah-type-c-button-top-main_3cb69f01-841d-4fef-8e66-c507957c98b2.webp?v=1786965966","url":"https:\/\/oneandes.com\/products\/fenix-button-top-21700-5000mah-rechargeable-battery-type-c-input-output-protection-circuit-built-in-large-capacity-3-6v-replacement-battery-for-flashlight-headlamps-etc","provider":"OneAndes","version":"1.0","type":"link"}