{"product_id":"makita-21v-battery-protection-board-5mos-balanced-temperature-control","title":"Makita 21V Battery Protection Board – 5MOS Balanced \u0026 Temp Control","description":"\n\u003ch2\u003eMakita 21V Replacement Battery Protection Board with Balanced Protection \u0026amp; Temperature Control\u003c\/h2\u003e\n\u003cp\u003eKeep your Makita 21V battery pack running safely and efficiently with this purpose-built \u003cstrong\u003ereplacement Battery Management System (BMS) protection board\u003c\/strong\u003e. Designed for 5-cell (5S) lithium battery packs, this board features \u003cstrong\u003e5MOS triple-alloy circuitry\u003c\/strong\u003e, built-in \u003cstrong\u003ecell balancing\u003c\/strong\u003e, and integrated \u003cstrong\u003etemperature control\u003c\/strong\u003e — giving your battery the protection it needs against overcharge, over-discharge, overcurrent, and thermal runaway.\u003c\/p\u003e\n\n\u003cp\u003eWhether you're repairing a worn-out Makita battery pack or building a replacement, this drop-in board makes the process straightforward and reliable.\u003c\/p\u003e\n\n\u003cp\u003e\u003cem\u003eMade in Mainland China.\u003c\/em\u003e\u003c\/p\u003e\n\n\u003ch3\u003eKey Features\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCompatible with Makita 21V battery packs\u003c\/strong\u003e — designed as a direct replacement board\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e5MOS 3-alloy design\u003c\/strong\u003e — robust MOSFETs for efficient current switching and low heat generation\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eBalanced cell protection\u003c\/strong\u003e — actively balances cells to maximize pack lifespan and capacity\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eTemperature control circuit\u003c\/strong\u003e — monitors and responds to heat buildup to prevent thermal damage\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMulti-layer protection\u003c\/strong\u003e — guards against overcharge, over-discharge, short circuit, and overcurrent\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eLightweight \u0026amp; compact\u003c\/strong\u003e — single set weight just 30g; easy to fit inside existing battery housings\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eVoltage range:\u003c\/strong\u003e USB 5–20V DC compatible\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePacking method:\u003c\/strong\u003e Individually bagged for safe delivery\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eProduct Specifications\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCompatible Voltage:\u003c\/strong\u003e 21V (5S Li-ion)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMOSFET Configuration:\u003c\/strong\u003e 5MOS 3 alloy\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCell Balancing:\u003c\/strong\u003e Yes\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eTemperature Control:\u003c\/strong\u003e Yes\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 30g per set\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eBattery \/ Charger Included:\u003c\/strong\u003e No\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eOrigin:\u003c\/strong\u003e Mainland China\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat's in the Box\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e1 × Makita 21V Replacement Battery Protection Board (bagged)\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\/1-channel-scr-solid-state-relay-switch-module-dc3-24v-40a-optocoupler\"\u003e1-Channel SCR Solid State Relay Module DC3-24V 40A Optocoupler\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"\/products\/0-60mpa-pressure-gauge-s60h-diesel-injector-nozzle-tester-8000psi\"\u003e0-60MPa Pressure Gauge for S60H Diesel Injector Nozzle Tester\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eFor general electrical safety guidance when working with lithium battery systems, refer to the U.S. Consumer Product Safety Commission (CPSC) – Lithium-Ion Battery Safety.\u003c\/p\u003e\n\n\u003cp\u003eLearn more: \u003ca href=\"https:\/\/en.wikipedia.org\/wiki\/Battery_management_system\" target=\"_blank\" rel=\"noopener\"\u003eBattery management system\u003c\/a\u003e\u003c\/p\u003e\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003ch4\u003eQ: Is this battery protection board compatible with all Makita 21V battery packs?\u003c\/h4\u003e\n\u003cp\u003eA: This replacement BMS protection board is designed for Makita 21V (5S lithium-ion) battery packs with balanced protection. It is recommended to verify your existing board's layout and connector configuration before installing to ensure a proper fit.\u003c\/p\u003e\n\n\u003ch4\u003eQ: What does \"balanced protection\" mean on this BMS board?\u003c\/h4\u003e\n\u003cp\u003eA: Cell balancing ensures that all individual cells within the battery pack charge and discharge at equal rates. This prevents any single cell from overcharging or over-discharging, which significantly extends overall battery pack lifespan and maintains consistent performance.\u003c\/p\u003e\n\n\u003ch4\u003eQ: Does the temperature control feature protect against overheating during charging?\u003c\/h4\u003e\n\u003cp\u003eA: Yes. The integrated temperature control circuit monitors heat levels within the battery pack during both charging and discharging. If temperatures exceed safe thresholds, the board will cut off current flow to prevent thermal damage or potential hazards.\u003c\/p\u003e\n\n\u003ch4\u003eQ: Does this board come with a battery or charger?\u003c\/h4\u003e\n\u003cp\u003eA: No — this listing is for the replacement protection board only. No battery cells or charger are included.\u003c\/p\u003e\n\n\u003cscript type=\"application\/ld+json\"\u003e{\"@context\": \"https:\/\/schema.org\", \"@type\": \"FAQPage\", \"mainEntity\": [{\"@type\": \"Question\", \"name\": \"Is this battery protection board compatible with all Makita 21V battery packs?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"This replacement BMS protection board is designed for Makita 21V (5S lithium-ion) battery packs with balanced protection. 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No battery cells or charger are included.\"}}]}\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:\/\/oasis-select.com\/\"}, {\"@type\": \"ListItem\", \"position\": 2, \"name\": \"Electronics \u0026 Tech\", \"item\": \"https:\/\/oasis-select.com\/collections\/electronics-tech\"}, {\"@type\": \"ListItem\", \"position\": 3, \"name\": \"Makita 21V Battery Protection Board – 5MOS Balanced \u0026 Temp Control\", \"item\": \"https:\/\/oasis-select.com\/products\/makita-21v-battery-protection-board-5mos-balanced-temperature-control\"}]}\u003c\/script\u003e","brand":"Oasis Select","offers":[{"title":"A","offer_id":47723809898601,"sku":"14:771#A","price":16.78,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0679\/7931\/3257\/files\/S580e29ab93674df8bd74c7c2598e8084I.webp?v=1782404323","url":"https:\/\/oasis-select.com\/products\/makita-21v-battery-protection-board-5mos-balanced-temperature-control","provider":"Oasis Select","version":"1.0","type":"link"}