{"product_id":"industrial-grade-backup-power-supply-21700-6-strings-battery-box-with-bms-power-box-welding-free-overcharge-discharge-protection","title":"21700 6S1P Battery Box Kit | Weld-Free + Built-in 40A BMS | DIY 25.2V Backup Power Supply","description":"\u003ch2\u003eBuild Your Own Portable Power Station — No Welding Required\u003c\/h2\u003e\n\u003cp\u003eTurn six 21700 lithium cells into a compact, ready-to-use 25.2V backup power supply. This weld-free 6S1P battery box comes with a built-in 40A protection board (BMS) with static equilibrium, so you get overcharge and over-discharge protection, simple drop-in assembly, and reliable power for backup use, camping, DIY projects, and off-grid setups.\u003c\/p\u003e\n\u003ch3\u003eWhy you'll love it\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eNo welding, no soldering\u003c\/strong\u003e: spring-loaded cell slots let you drop in six matched 21700 cells — no spot welder needed.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBuilt-in 6S 40A BMS\u003c\/strong\u003e: integrated protection board with static equilibrium guards against overcharge and over-discharge while keeping cells balanced.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eReal-world power\u003c\/strong\u003e: full-charge voltage of 25.2V with an operating range of DC 18–25.2V; recommended continuous discharge 20A (sustainable 10–20A, instantaneous up to 40A depending on the cells you install).\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCharge your way\u003c\/strong\u003e: recommended charging current 5A (regular 5–8A) using a 25.2V lithium battery charger.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThree output interfaces, all in parallel\u003c\/strong\u003e: DC5.5-2.5 port (25.2V lithium charger connection \/ small-current discharge), XT30 (low-power charge or discharge), and XT60 (large-current charge or discharge), plus a power switch (left = closed, right = open) to cut output when you're finished.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eSpecifications (as listed by the supplier)\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eConfiguration: 6S1P (6 strings, 1 parallel)\u003c\/li\u003e\n\u003cli\u003eFull-charge voltage: 25.2V\u003c\/li\u003e\n\u003cli\u003eOperating voltage range: approx. DC 18–25.2V (does not support voltage regulation)\u003c\/li\u003e\n\u003cli\u003eProtection board: 6S 40A with static equilibrium\u003c\/li\u003e\n\u003cli\u003eRecommended charging current: 5A suggested; 5–8A regular\u003c\/li\u003e\n\u003cli\u003eRecommended continuous discharge: 20A; sustainable 10–20A; instantaneous 40A (depends on cells used)\u003c\/li\u003e\n\u003cli\u003eInterfaces: 1x DC5.5-2.5 socket, 1x XT30 male, 1x XT60 male, 1x power switch — all three interfaces in parallel, directly connected to the protection board\u003c\/li\u003e\n\u003cli\u003eCell slots: spring-loaded (manganese steel, nickel); does not support pointed non-standard batteries\u003c\/li\u003e\n\u003cli\u003eSize (21700 model): 168 x 87 x 28 mm (L x W x H, excluding plastic columns)\u003c\/li\u003e\n\u003cli\u003eType: battery storage box; Model Number: 18650\/21700\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eImportant — please read before ordering\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBatteries NOT included\u003c\/strong\u003e: you supply your own six brand-new batteries.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCells must be matched\u003c\/strong\u003e: all batteries must be consistent in capacity, voltage, and internal resistance.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCharger not included\u003c\/strong\u003e: use your own 25.2V 5A lithium battery charger (DC2.5 connector).\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNot for vehicle starting\u003c\/strong\u003e: this box does not support starting vehicles.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSafety\u003c\/strong\u003e: do not expose all interfaces (risk of short circuit); turn the power switch off when finished; confirm your charger is a 25.2V lithium-battery charger only — do not mischarge.\u003c\/li\u003e\n\u003cli\u003eOverall capacity, endurance, and lifespan of the finished pack are determined entirely by the batteries you install.\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"The Current Supply ","offers":[{"title":"21700 box","offer_id":67652978049390,"sku":"14:173#21700 box","price":112.99,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0979\/0908\/0430\/files\/S006c2ff4b596472c8376c94d0b3ab3580_24b8c3d8-0141-45c1-a099-21dc3db35461.webp?v=1791131620","url":"https:\/\/sick.parts\/products\/industrial-grade-backup-power-supply-21700-6-strings-battery-box-with-bms-power-box-welding-free-overcharge-discharge-protection","provider":"The Current Supply ","version":"1.0","type":"link"}