{"product_id":"3s-4s-5s-bms-100a-li-ion-battery-protection-balance-12v-16-8v-21v","title":"3S \/ 4S \/ 5S BMS 100A Li-Ion Battery Protection Board with Balance — 12V \/ 16.8V \/ 21V","description":"\u003ch2\u003e3S \/ 4S \/ 5S BMS 100A Li-Ion Battery Protection Board with Cell Balancing\u003c\/h2\u003e\u003cp\u003eThis \u003cstrong\u003eBMS (Battery Management System) protection board\u003c\/strong\u003e provides comprehensive protection for \u003cstrong\u003e3S (12.6V), 4S (16.8V), and 5S (21V)\u003c\/strong\u003e lithium-ion and lithium-polymer battery packs at up to \u003cstrong\u003e100A continuous discharge current\u003c\/strong\u003e. Built-in \u003cstrong\u003ecell balancing\u003c\/strong\u003e equalizes individual cell voltages during charging to maximize pack capacity and cycle life.\u003c\/p\u003e\u003ch3\u003eKey Specifications by Cell Count\u003c\/h3\u003e\u003ctable\u003e\n\u003ctr\u003e\n\u003cth\u003eConfiguration\u003c\/th\u003e\n\u003cth\u003eNominal Voltage\u003c\/th\u003e\n\u003cth\u003eFull Charge\u003c\/th\u003e\n\u003cth\u003eCut-Off (UVP)\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e3S (3 cells)\u003c\/td\u003e\n\u003ctd\u003e11.1V\u003c\/td\u003e\n\u003ctd\u003e12.6V\u003c\/td\u003e\n\u003ctd\u003e~9.0V\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e4S (4 cells)\u003c\/td\u003e\n\u003ctd\u003e14.8V\u003c\/td\u003e\n\u003ctd\u003e16.8V\u003c\/td\u003e\n\u003ctd\u003e~12.0V\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e5S (5 cells)\u003c\/td\u003e\n\u003ctd\u003e18.5V\u003c\/td\u003e\n\u003ctd\u003e21.0V\u003c\/td\u003e\n\u003ctd\u003e~15.0V\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\u003ch3\u003eProtection Features\u003c\/h3\u003e\u003ctable\u003e\n\u003ctr\u003e\n\u003cth\u003eProtection\u003c\/th\u003e\n\u003cth\u003eFunction\u003c\/th\u003e\n\u003cth\u003eThreshold\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOVP (Overvoltage)\u003c\/td\u003e\n\u003ctd\u003eStops charging when cell exceeds max voltage\u003c\/td\u003e\n\u003ctd\u003e4.25V ±0.05V per cell\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eUVP (Undervoltage)\u003c\/td\u003e\n\u003ctd\u003eDisconnects load when cell drops below min\u003c\/td\u003e\n\u003ctd\u003e2.5V ±0.1V per cell\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOCP (Overcurrent)\u003c\/td\u003e\n\u003ctd\u003eCuts off discharge at excess current\u003c\/td\u003e\n\u003ctd\u003e100A ±20%\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSCP (Short Circuit)\u003c\/td\u003e\n\u003ctd\u003eInstant disconnect on short circuit\u003c\/td\u003e\n\u003ctd\u003e\u0026lt;500μs response\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCell Balancing\u003c\/td\u003e\n\u003ctd\u003eEqualizes cell voltages during charge\u003c\/td\u003e\n\u003ctd\u003ePassive balancing\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\u003ch3\u003eWhy Choose This BMS?\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e100A Continuous Discharge\u003c\/strong\u003e — Handles high-current loads: e-bike motors, power tools, inverters\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCell Balancing\u003c\/strong\u003e — Passive balancing prevents cell divergence and extends pack cycle life\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAll-in-One Protection\u003c\/strong\u003e — OVP + UVP + OCP + SCP in one board; no additional protection circuits needed\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e3S\/4S\/5S Options\u003c\/strong\u003e — Select the correct cell count for your battery pack voltage\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLow RDS(on) MOSFETs\u003c\/strong\u003e — Minimal voltage drop and heat at high discharge currents\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eTypical Applications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eE-bike and electric scooter 36V\/48V battery pack BMS\u003c\/li\u003e\n\u003cli\u003ePower tool battery pack (drill, saw, grinder)\u003c\/li\u003e\n\u003cli\u003eDIY lithium battery pack for solar energy storage\u003c\/li\u003e\n\u003cli\u003eElectric skateboard and personal mobility device\u003c\/li\u003e\n\u003cli\u003ePortable power station battery management\u003c\/li\u003e\n\u003cli\u003eRC car and drone high-current battery protection\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eWiring Guide\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eB-\u003c\/strong\u003e → Battery pack negative terminal.\u003cbr\u003e\u003cstrong\u003eB1, B2, B3 (B4, B5)\u003c\/strong\u003e → Cell balance wires (between each cell junction).\u003cbr\u003e\u003cstrong\u003eP-\u003c\/strong\u003e → Load negative terminal (discharge output).\u003cbr\u003e\u003cstrong\u003eC-\u003c\/strong\u003e → Charger negative terminal (charge input).\u003cbr\u003eBattery positive connects directly to load\/charger positive (no BMS switching on positive rail).\u003c\/p\u003e\u003ch3\u003eFAQ\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eQ: Can this BMS handle 18650 cells?\u003c\/strong\u003e\u003cbr\u003eA: Yes — compatible with any Li-ion chemistry (18650, 21700, LiPo) with 4.2V per cell nominal. Ensure cell capacity matches the 100A discharge rating (minimum 20Ah pack for 1C discharge).\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eQ: Does this BMS support simultaneous charge and discharge?\u003c\/strong\u003e\u003cbr\u003eA: Depends on the board version. Boards with separate C- and P- terminals support simultaneous charge\/discharge. Boards with combined port do not.\u003c\/p\u003e\u003ch3\u003ePackage Contents\u003c\/h3\u003e\u003cul\u003e\u003cli\u003e1× 3S \/ 4S \/ 5S BMS Protection Board (100A, with balancing)\u003c\/li\u003e\u003c\/ul\u003e","brand":"Keszoox","offers":[{"title":"5S 21V 100A","offer_id":46991508865259,"sku":"14:496#5S 21V 100A","price":10.32,"currency_code":"USD","in_stock":true},{"title":"3S 12V 100A","offer_id":46991508898027,"sku":"14:193#3S 12V 100A","price":9.52,"currency_code":"USD","in_stock":true},{"title":"4S 16.8V 100A","offer_id":46991508930795,"sku":"14:366#4S 16.8V 100A","price":9.76,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0677\/1005\/8731\/files\/3s-4s-5s-bms-100a-lithium-battery-protection-board-balance-charging.webp?v=1761365958","url":"https:\/\/keszoox.com\/products\/3s-4s-5s-bms-100a-li-ion-battery-protection-balance-12v-16-8v-21v","provider":"Keszoox","version":"1.0","type":"link"}