{"product_id":"21v-7mos-li-battery-protection-board-electric-tools-bms","title":"21V 7MOS Li-Battery Protection Board for Electric Tools BMS","description":"\n\u003ch2\u003e21V 7MOS Li-Battery Protection Board for Electric Tools\u003c\/h2\u003e\n\u003cp\u003eKeep your electric tool battery packs running safely and efficiently with this \u003cstrong\u003e21V 7MOS Lithium Battery Protection Board\u003c\/strong\u003e. Designed for DIY enthusiasts, hobbyists, and professionals alike, this compact BMS (Battery Management System) board features a built-in balancing circuit and temperature protection to safeguard your battery cells from overcharge, over-discharge, and overheating.\u003c\/p\u003e\n\n\u003ch3\u003eKey Features\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003e21V Rated Voltage\u003c\/strong\u003e – Compatible with standard 5-series lithium-ion battery packs used in cordless electric tools\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e7 MOS Design\u003c\/strong\u003e – Seven MOSFET switches deliver robust current handling for demanding power tool applications\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCell Balancing Circuit\u003c\/strong\u003e – Automatically equalizes cell voltages to maximize battery life and maintain consistent performance\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eTemperature Protection\u003c\/strong\u003e – Integrated thermal cutoff prevents damage from overheating during heavy use or charging\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eOvercharge \u0026amp; Over-Discharge Protection\u003c\/strong\u003e – Keeps each cell within safe operating limits for long-term reliability\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCompact Form Factor\u003c\/strong\u003e – Measures approximately 90.5 × 62 mm, fitting neatly inside most standard electric tool battery enclosures\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDurable Construction\u003c\/strong\u003e – Built with a combination of plastic and metal components for lasting durability\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eSpecifications\u003c\/h3\u003e\n\u003ctable style=\"border-collapse: collapse; width: 100%;\"\u003e\n  \u003ctr style=\"background-color: #f2f2f2;\"\u003e\n    \u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003e\u003cstrong\u003eVoltage\u003c\/strong\u003e\u003c\/td\u003e\n    \u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003e21V\u003c\/td\u003e\n  \u003c\/tr\u003e\n  \u003ctr\u003e\n    \u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003e\u003cstrong\u003eMOS Quantity\u003c\/strong\u003e\u003c\/td\u003e\n    \u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003e7 MOS\u003c\/td\u003e\n  \u003c\/tr\u003e\n  \u003ctr style=\"background-color: #f2f2f2;\"\u003e\n    \u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003e\u003cstrong\u003eMaterial\u003c\/strong\u003e\u003c\/td\u003e\n    \u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003ePlastic + Metal\u003c\/td\u003e\n  \u003c\/tr\u003e\n  \u003ctr\u003e\n    \u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003e\u003cstrong\u003eDimensions\u003c\/strong\u003e\u003c\/td\u003e\n    \u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003eApprox. 90.5 × 62 mm\u003c\/td\u003e\n  \u003c\/tr\u003e\n  \u003ctr style=\"background-color: #f2f2f2;\"\u003e\n    \u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003e\u003cstrong\u003ePackage Contents\u003c\/strong\u003e\u003c\/td\u003e\n    \u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003e1 × Protection Board (batteries not included)\u003c\/td\u003e\n  \u003c\/tr\u003e\n  \u003ctr\u003e\n    \u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003e\u003cstrong\u003eCountry of Origin\u003c\/strong\u003e\u003c\/td\u003e\n    \u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003eMade in China\u003c\/td\u003e\n  \u003c\/tr\u003e\n\u003c\/table\u003e\n\n\u003ch3\u003eWho Is This For?\u003c\/h3\u003e\n\u003cp\u003eThis protection board is ideal for anyone rebuilding or repairing cordless tool battery packs, designing custom battery systems, or working on electronics DIY projects. Whether you're replacing a faulty BMS in a drill, circular saw, or other 21V cordless tool, this board is a reliable, cost-effective solution.\u003c\/p\u003e\n\n\u003ch3\u003eImportant Notes\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003eSlight color variation from product images may occur due to monitor settings and lighting conditions.\u003c\/li\u003e\n  \u003cli\u003ePlease allow a minor measurement deviation (±1–2 mm) for stated dimensions.\u003c\/li\u003e\n  \u003cli\u003eBatteries are \u003cstrong\u003enot included\u003c\/strong\u003e.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eRelated Products You May Like\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\u003ca href=\"\/products\/10pcs-2-pin-quick-splice-spring-wire-connectors-lock-terminals\"\u003e10pcs 2-Pin Spring Wire Connectors – Quick Splice Lock Terminals\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"\/products\/stainless-steel-self-tapping-screws-m2-2-m4-8-phillips-wood-hinge\"\u003e10PCS Stainless Steel Self-Tapping Screws M2.2–M4.8 Phillips\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"\/products\/12pcs-16mm-momentary-push-button-switch-1no-metal-2-pin-self-reset\"\u003e12pcs 16mm Momentary Push Button Switch 1NO Metal 2-Pin Self-Reset\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eLearn more: \u003ca href=\"https:\/\/www.epa.gov\/recycle\/used-lithium-ion-batteries\" target=\"_blank\" rel=\"noopener\"\u003eEPA guidance on lithium-ion battery handling\u003c\/a\u003e\u003c\/p\u003e\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003ch4\u003eQ: What type of battery cells is this 21V protection board compatible with?\u003c\/h4\u003e\n\u003cp\u003eA: This 21V Li-battery protection board is designed for use with 5-series lithium-ion (Li-ion) battery packs, which are commonly found in 21V cordless electric tools such as drills, screwdrivers, and saws. It is compatible with standard 18650-type or similar cylindrical Li-ion cells arranged in a 5S configuration.\u003c\/p\u003e\n\n\u003ch4\u003eQ: Does this board include short-circuit protection?\u003c\/h4\u003e\n\u003cp\u003eA: Yes. The 7MOS design and built-in protection circuitry provide safeguards against overcharge, over-discharge, overcurrent, and short-circuit conditions, helping to protect both the battery cells and the connected device from damage.\u003c\/p\u003e\n\n\u003ch4\u003eQ: How does the balancing circuit work?\u003c\/h4\u003e\n\u003cp\u003eA: The integrated cell balancing circuit monitors the voltage of each individual cell in the battery pack and redistributes charge as needed to ensure all cells remain at an equal voltage level. This extends overall battery life and prevents premature cell degradation caused by imbalanced charging.\u003c\/p\u003e\n\n\u003ch4\u003eQ: Are batteries included with this protection board?\u003c\/h4\u003e\n\u003cp\u003eA: No, batteries are not included. The package contains only 1 × 21V 7MOS Li-battery Protection Board. You will need to source compatible lithium-ion battery cells separately.\u003c\/p\u003e\n\u003c!-- production-packaging-notice --\u003e\n\u003ch3\u003eProduction \u0026amp; Packaging Notice\u003c\/h3\u003e\n\u003cp\u003eTo maintain high stock availability and fast shipping times, our items are sourced from multiple verified manufacturing facilities. While the core quality, materials, and product specifications remain identical, you may notice slight variations in the packaging design, manufacturing origin, or the wording of the printed instructions.\u003c\/p\u003e\n\u003cscript type=\"application\/ld+json\"\u003e{\"@context\": \"https:\/\/schema.org\", \"@type\": \"FAQPage\", \"mainEntity\": [{\"@type\": \"Question\", \"name\": \"What type of battery cells is this 21V protection board compatible with?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"This 21V Li-battery protection board is designed for use with 5-series lithium-ion (Li-ion) battery packs, which are commonly found in 21V cordless electric tools such as drills, screwdrivers, and saws. It is compatible with standard 18650-type or similar cylindrical Li-ion cells arranged in a 5S configuration.\"}}, {\"@type\": \"Question\", \"name\": \"Does this board include short-circuit protection?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes. 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You will need to source compatible lithium-ion battery cells separately.\"}}]}\u003c\/script\u003e\n\u003cscript type=\"application\/ld+json\"\u003e{\"@context\": \"https:\/\/schema.org\", \"@type\": \"BreadcrumbList\", \"itemListElement\": [{\"@type\": \"ListItem\", \"position\": 1, \"name\": \"Home\", \"item\": \"https:\/\/68k0rh-yt.myshopify.com\/\"}, {\"@type\": \"ListItem\", \"position\": 2, \"name\": \"Home page\", \"item\": \"https:\/\/68k0rh-yt.myshopify.com\/collections\/frontpage\"}, {\"@type\": \"ListItem\", \"position\": 3, \"name\": \"21V 7MOS Li-Battery Protection Board for Electric Tools BMS\", \"item\": \"https:\/\/68k0rh-yt.myshopify.com\/products\/21v-7mos-li-battery-protection-board-electric-tools-bms\"}]}\u003c\/script\u003e","brand":"Richie's","offers":[{"title":"Default Title","offer_id":57574215090342,"sku":"1005012730677973-Default Title","price":29.05,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0785\/2182\/7494\/files\/S59ffc396332347479b9b16e43ca5c134j_ec03c43c-15d7-464c-a3ce-11264b494d5c.webp?v=1791241067","url":"https:\/\/richiesmart.com\/products\/21v-7mos-li-battery-protection-board-electric-tools-bms","provider":"Richie's","version":"1.0","type":"link"}