{"product_id":"5s-bms-21v-20a-li-ion-battery-protection-board-power-tools","title":"5S BMS 21V 20A Li-Ion Battery Protection Board for Power Tools","description":"\n\u003ch2\u003e5S BMS 21V 20A Li-Ion Battery Management Protection Board\u003c\/h2\u003e\n\u003cp\u003eKeep your lithium battery packs running safely and efficiently with this high-quality \u003cstrong\u003e5S BMS (Battery Management System) Protection Board\u003c\/strong\u003e. Designed specifically for 5-series Li-ion battery packs, this compact PCBA is ideal for electric drills and other cordless power tools. Made in Mainland China.\u003c\/p\u003e\n\n\u003ch3\u003eKey Features\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003e5S Li-Ion Compatibility:\u003c\/strong\u003e Purpose-built for 5-cell series lithium-ion battery packs up to 21V charge voltage.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSmart IC Processor:\u003c\/strong\u003e Uses a dedicated 5S lithium battery IC to monitor real-time cell voltage, charge\/discharge current, and ambient temperature for each individual cell.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eComprehensive Protection:\u003c\/strong\u003e Built-in overcharge protection, over-discharge protection, and short circuit protection for safe, stable operation.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eHigh Continuous Discharge:\u003c\/strong\u003e Supports 8–20A continuous discharge current — well-suited for demanding power tool applications.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eUltra-Low Power Consumption:\u003c\/strong\u003e Working current of approximately 25µA and quiescent current of approximately 6µA help extend overall battery longevity.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCompact Size:\u003c\/strong\u003e Measures just 58 × 63 mm — easy to integrate into existing battery pack housings.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e2 MOSFETs:\u003c\/strong\u003e Dual MOSFET design (2 MOS) for reliable switching and efficient current handling.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eTechnical Specifications\u003c\/h3\u003e\n\u003ctable\u003e\n  \u003ctbody\u003e\n    \u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eConfiguration\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e5S (5 cells in series)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eCharge Voltage\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e21V\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eSingle Cell Charge Voltage\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e4.25V\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eContinuous Discharge Current\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e8–20A\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eOvercharge Detection Voltage (per cell)\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e4.25V\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eWorking Current\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e~25µA\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eQuiescent Current\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e~6µA\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003ePCB Size\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e58 × 63 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eModel\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e5S21V-2MOS\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003ePackage Contents\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e1 × BMS Protection Board\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch3\u003eWhat Is a BMS Protection Board?\u003c\/h3\u003e\n\u003cp\u003eA Battery Management System (BMS) protection board is the critical safety layer between your lithium cells and your device. It continuously monitors each cell's charge state and intervenes instantly to prevent overcharging, deep discharging, or dangerous short circuits — all of which can permanently damage a lithium battery pack. Choosing the right BMS and installing it correctly is one of the most important steps in building or maintaining a long-lasting Li-ion battery pack.\u003c\/p\u003e\n\n\u003ch3\u003eImportant Notes\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003eDue to manual measurement, please allow a tolerance of ±1–3 mm.\u003c\/li\u003e\n  \u003cli\u003eColors may appear slightly different on screen versus the actual product due to monitor calibration differences.\u003c\/li\u003e\n  \u003cli\u003eBattery cells, charger, and power tool are \u003cstrong\u003eNOT included\u003c\/strong\u003e — this listing is for the BMS protection board only.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eYou May Also Like\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\u003ca href=\"\/products\/air-compressor-pressure-gauge-0-10-0-12-0-25-bar-hydraulic-diy\"\u003eAir Compressor Pressure Gauge 0-10\/0-12\/0-25 Bar | DIY Tool\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"\/products\/electromagnetic-induction-tester-coil-motherboard-fault-detector\"\u003eElectromagnetic Induction Tester – Coil \u0026amp; Circuit Fault Detector\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eLearn more: \u003ca href=\"https:\/\/www.energystar.gov\/products\" target=\"_blank\" rel=\"noopener\"\u003eENERGY STAR product efficiency guidance\u003c\/a\u003e\u003c\/p\u003e\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003ch4\u003eQ: What does the 5S BMS 21V protection board do for my lithium battery pack?\u003c\/h4\u003e\n\u003cp\u003eA: The 5S BMS protection board continuously monitors each of the five series-connected Li-ion cells in real time, tracking voltage, charge\/discharge current, and temperature. It automatically activates overcharge protection, over-discharge protection, and short circuit protection to keep your battery pack safe and extend its working life.\u003c\/p\u003e\n\u003ch4\u003eQ: Is this BMS board compatible with my cordless electric drill?\u003c\/h4\u003e\n\u003cp\u003eA: This board is designed for 5-series (5S) Li-ion battery packs with a 21V charge voltage and a continuous discharge current of 8–20A, making it suitable for most handheld cordless drills and similar power tools that use a 5-cell Li-ion configuration. Always verify your tool's battery specifications before installing.\u003c\/p\u003e\n\u003ch4\u003eQ: Does this listing include batteries or a charger?\u003c\/h4\u003e\n\u003cp\u003eA: No — this listing includes only the BMS protection board (1 piece). Batteries, charger, and power tool are sold separately. The BMS is the circuit board component that you integrate into your battery pack assembly.\u003c\/p\u003e\n\n\u003cscript type=\"application\/ld+json\"\u003e{\"@context\": \"https:\/\/schema.org\", \"@type\": \"FAQPage\", \"mainEntity\": [{\"@type\": \"Question\", \"name\": \"What does the 5S BMS 21V protection board do for my lithium battery pack?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"The 5S BMS protection board continuously monitors each of the five series-connected Li-ion cells in real time, tracking voltage, charge\/discharge current, and temperature. 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The BMS is the circuit board component that you integrate into your battery pack assembly.\"}}]}\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:\/\/n8ande-60.myshopify.com\/\"}, {\"@type\": \"ListItem\", \"position\": 2, \"name\": \"Home page\", \"item\": \"https:\/\/n8ande-60.myshopify.com\/collections\/frontpage\"}, {\"@type\": \"ListItem\", \"position\": 3, \"name\": \"5S BMS 21V 20A Li-Ion Battery Protection Board for Power Tools\", \"item\": \"https:\/\/n8ande-60.myshopify.com\/products\/5s-bms-21v-20a-li-ion-battery-protection-board-power-tools\"}]}\u003c\/script\u003e","brand":"Axl","offers":[{"title":"onesize","offer_id":44169809035351,"sku":"14:193#onesize","price":13.94,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0676\/6008\/7383\/files\/S9cc01409230d4fe1972034f725fcd6923_bba9c1f8-1827-42e2-a951-f79a56530ff8.webp?v=1786801557","url":"https:\/\/axlcustomersupport.com\/products\/5s-bms-21v-20a-li-ion-battery-protection-board-power-tools","provider":"Axl","version":"1.0","type":"link"}