{"product_id":"li-fe-battery-lifepo4-pcm-bms-12-8v-protection-circuit-management-module-board","title":"4S 12.8V LiFePO4 Battery PCM BMS Protection Circuit Board (8 Models Available)","description":"\u003ch2\u003e\u003cstrong\u003e4S 12.8V LiFePO4 Battery Protection Board (BMS\/PCM) - 8 Models Available\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cp\u003eProfessional Battery Management System (BMS) \/ Protection Circuit Module (PCM) specifically designed for 4S (12.8V) LiFePO4 (Lithium Iron Phosphate) battery packs. Available in 8 different models with current ratings from 4A to 20A and various sizes to fit different applications. Features comprehensive protection including overcharge, over-discharge, overcurrent, short circuit, and temperature protection, plus built-in cell balancing function. Perfect for DIY 12V LiFePO4 battery packs, solar systems, RVs, marine applications, and backup power systems.\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eKey Features\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e8 Models Available:\u003c\/strong\u003e Choose from 4A to 20A current ratings\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e4S Configuration:\u003c\/strong\u003e For 12.8V (4-cell) LiFePO4 battery packs\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLiFePO4 Specific:\u003c\/strong\u003e Calibrated for Li-Fe voltage characteristics (3.2V per cell)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eComprehensive Protection:\u003c\/strong\u003e Overcharge, over-discharge, overcurrent, short circuit, temperature\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCell Balancing:\u003c\/strong\u003e Built-in balancing function for optimal performance\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMultiple Sizes:\u003c\/strong\u003e Various form factors from 16×50mm to 61×61mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eQuality Components:\u003c\/strong\u003e Reliable MOSFETs and protection ICs\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLow Self-Consumption:\u003c\/strong\u003e Minimal power drain on battery\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cstrong\u003ePackage Contents\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e1× 4S 12.8V LiFePO4 Protection Board (BMS\/PCM) - model as selected\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cstrong\u003eAvailable Models - Choose Based on Your Current Needs\u003c\/strong\u003e\u003c\/h3\u003e\n\u003ctable style=\"width: 100%; border-collapse: collapse;\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth style=\"padding: 8px; border: 1px solid #ddd;\"\u003eModel\u003c\/th\u003e\n\u003cth style=\"padding: 8px; border: 1px solid #ddd;\"\u003eCurrent\u003c\/th\u003e\n\u003cth style=\"padding: 8px; border: 1px solid #ddd;\"\u003eSize (mm)\u003c\/th\u003e\n\u003cth style=\"padding: 8px; border: 1px solid #ddd;\"\u003eWeight\u003c\/th\u003e\n\u003cth style=\"padding: 8px; border: 1px solid #ddd;\"\u003eBest For\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003e\u003cstrong\u003e4A Round\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003e4A\u003c\/td\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003e25.8mm Ø\u003c\/td\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003e33g\u003c\/td\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003eLow current, compact cylindrical packs\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003e\u003cstrong\u003e8A Model 1\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003e8A\u003c\/td\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003e22 × 50\u003c\/td\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003e34g\u003c\/td\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003eCompact applications, narrow spaces\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003e\u003cstrong\u003e8A Model 2\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003e8A\u003c\/td\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003e30 × 70\u003c\/td\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003e39g\u003c\/td\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003eStandard applications\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003e\u003cstrong\u003e8A Model 3\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003e8A\u003c\/td\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003e16 × 50\u003c\/td\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003e33g\u003c\/td\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003eUltra-compact, tight spaces\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003e\u003cstrong\u003e10A\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003e10A\u003c\/td\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003e34 × 42\u003c\/td\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003e46g\u003c\/td\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003eMedium current applications\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003e\u003cstrong\u003e16A\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003e16A\u003c\/td\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003e31 × 62\u003c\/td\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003e42g\u003c\/td\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003eHigher current, power tools\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003e\u003cstrong\u003e20A Model 1\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003e20A\u003c\/td\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003e61 × 61\u003c\/td\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003e50g\u003c\/td\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003eHigh current, square format\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003e\u003cstrong\u003e20A Model 2\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003e20A\u003c\/td\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003e34 × 60\u003c\/td\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003e41g\u003c\/td\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003eHigh current, rectangular format\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch3\u003e\u003cstrong\u003e\u003c\/strong\u003e\u003c\/h3\u003e\n\u003ch3\u003e\u003cstrong\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0732\/9133\/3821\/files\/FPME04S1_72c5a3dd-4fef-4d76-98bf-2c92f770e22a.png?v=1772522223\" alt=\"\"\u003e\u003c\/strong\u003e\u003c\/h3\u003e\n\u003ch3\u003e\u003cstrong\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0732\/9133\/3821\/files\/FPME04S2_9740009e-429d-4779-9115-376ee376590b.png?v=1772522223\" alt=\"\"\u003e\u003c\/strong\u003e\u003c\/h3\u003e\n\u003ch3\u003e\u003cstrong\u003eProtection Features\u003c\/strong\u003e\u003c\/h3\u003e\n\u003ctable style=\"width: 100%; border-collapse: collapse;\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth style=\"padding: 8px; border: 1px solid #ddd;\"\u003eProtection Type\u003c\/th\u003e\n\u003cth style=\"padding: 8px; border: 1px solid #ddd;\"\u003eFunction\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003e\u003cstrong\u003eOvercharge Protection\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003eDisconnects when any cell exceeds 3.65V\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003e\u003cstrong\u003eOver-discharge Protection\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003eDisconnects when any cell drops below 2.5V\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003e\u003cstrong\u003eOvercurrent Protection\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003eDisconnects when current exceeds rated limit\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003e\u003cstrong\u003eShort Circuit Protection\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003eInstantly disconnects on short circuit\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003e\u003cstrong\u003eCell Balancing\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003eBalances cells during charging for optimal performance\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003e\u003cstrong\u003eTemperature Protection\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003eProtects against overheating\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch3\u003e\u003cstrong\u003eStep-by-Step Installation Instructions\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003e✅ Follow These Steps Carefully for Safe Installation\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eStep 1: Preparation \u0026amp; Safety\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eCRITICAL:\u003c\/strong\u003e Disconnect all power sources before starting\u003c\/li\u003e\n\u003cli\u003eVerify you have a 4S (4-cell) LiFePO4 battery pack\u003c\/li\u003e\n\u003cli\u003eSelect the correct BMS model based on your maximum current draw\u003c\/li\u003e\n\u003cli\u003ePrepare tools: soldering iron, solder, wire cutters, multimeter, heat shrink tubing\u003c\/li\u003e\n\u003cli\u003eWire gauge recommendations:\u003c\/li\u003e\n\u003cli\u003e4-8A: 18-20 AWG\u003c\/li\u003e\n\u003cli\u003e10-16A: 14-16 AWG\u003c\/li\u003e\n\u003cli\u003e20A: 12-14 AWG\u003c\/li\u003e\n\u003cli\u003eWork in a well-ventilated area with good lighting\u003c\/li\u003e\n\u003cli\u003eWear safety glasses\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eStep 2: Identify Connection Points on BMS\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eLocate the following pads\/wires on the BMS board:\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eB-\u003c\/strong\u003e (Battery Negative): Connect to negative terminal of battery pack\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eB+\u003c\/strong\u003e (Battery Positive): Connect to positive terminal of battery pack\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eP-\u003c\/strong\u003e (Load\/Charger Negative): Output negative terminal\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eP+\u003c\/strong\u003e (Load\/Charger Positive): Output positive terminal\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBalance Wires (4S):\u003c\/strong\u003e B-, B1, B2, B3, B+\u003c\/li\u003e\n\u003cli\u003eRefer to the wiring diagram (usually printed on the board or in documentation)\u003c\/li\u003e\n\u003cli\u003eTake a photo of the diagram for reference during installation\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eStep 3: Connect Balance Wires (Critical Step)\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eFor 4S (12.8V) Configuration:\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eB-\u003c\/strong\u003e → Negative terminal of Cell 1 (first cell)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eB1\u003c\/strong\u003e → Connection point between Cell 1 and Cell 2\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eB2\u003c\/strong\u003e → Connection point between Cell 2 and Cell 3\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eB3\u003c\/strong\u003e → Connection point between Cell 3 and Cell 4\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eB+\u003c\/strong\u003e → Positive terminal of Cell 4 (last cell)\u003c\/li\u003e\n\u003cli\u003eUse thin wire (22-24 AWG) for balance connections\u003c\/li\u003e\n\u003cli\u003eLabel each wire BEFORE connecting (use masking tape)\u003c\/li\u003e\n\u003cli\u003eConnect in order from B- to B+\u003c\/li\u003e\n\u003cli\u003eDouble-check each connection with multimeter:\u003c\/li\u003e\n\u003cli\u003eB- to B1 should read ~3.2V\u003c\/li\u003e\n\u003cli\u003eB1 to B2 should read ~3.2V\u003c\/li\u003e\n\u003cli\u003eB2 to B3 should read ~3.2V\u003c\/li\u003e\n\u003cli\u003eB3 to B+ should read ~3.2V\u003c\/li\u003e\n\u003cli\u003eB- to B+ should read ~12.8V total\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eStep 4: Connect Main Power Wires\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eBattery Side Connections:\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003eConnect \u003cstrong\u003eB-\u003c\/strong\u003e pad to battery pack negative terminal\u003c\/li\u003e\n\u003cli\u003eConnect \u003cstrong\u003eB+\u003c\/strong\u003e pad to battery pack positive terminal\u003c\/li\u003e\n\u003cli\u003eUse appropriate wire gauge based on current rating\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eLoad\/Charger Side Connections:\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003eConnect \u003cstrong\u003eP-\u003c\/strong\u003e pad to load\/charger negative\u003c\/li\u003e\n\u003cli\u003eConnect \u003cstrong\u003eP+\u003c\/strong\u003e pad to load\/charger positive\u003c\/li\u003e\n\u003cli\u003eThese are your output terminals\u003c\/li\u003e\n\u003cli\u003eSolder all connections securely\u003c\/li\u003e\n\u003cli\u003eApply heat shrink tubing immediately after each solder joint\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eStep 5: Verify All Connections Before Power-On\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eCRITICAL - Check before applying power:\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e✅ All balance wires connected in correct sequence (B-, B1, B2, B3, B+)\u003c\/li\u003e\n\u003cli\u003e✅ No reversed polarity on any connection\u003c\/li\u003e\n\u003cli\u003e✅ All solder joints are solid and well-insulated\u003c\/li\u003e\n\u003cli\u003e✅ No short circuits between adjacent wires\u003c\/li\u003e\n\u003cli\u003e✅ Use multimeter to verify voltage at each balance point\u003c\/li\u003e\n\u003cli\u003e✅ Verify total pack voltage is approximately 12.8V (11V-14.6V range)\u003c\/li\u003e\n\u003cli\u003e✅ Check continuity from B- to P- and B+ to P+\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eStep 6: Initial Testing\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eConnect battery pack to BMS\u003c\/li\u003e\n\u003cli\u003eMeasure voltage at P+ and P- terminals with multimeter\u003c\/li\u003e\n\u003cli\u003eShould read full pack voltage (~12.8V)\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eIf no output voltage:\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003eBMS may be in protection mode (normal for new BMS)\u003c\/li\u003e\n\u003cli\u003eConnect charger briefly (5-10 seconds) to wake up BMS\u003c\/li\u003e\n\u003cli\u003eCheck output voltage again\u003c\/li\u003e\n\u003cli\u003eTest with low-current load first (1-2A)\u003c\/li\u003e\n\u003cli\u003eMonitor BMS temperature during first 10 minutes of use\u003c\/li\u003e\n\u003cli\u003eVerify protection functions:\u003c\/li\u003e\n\u003cli\u003eTest over-discharge protection (discharge to 10V, BMS should disconnect)\u003c\/li\u003e\n\u003cli\u003eTest overcharge protection (charge to 14.6V, BMS should disconnect)\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eStep 7: Final Assembly \u0026amp; Insulation\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eApply heat shrink tubing to all exposed wire connections\u003c\/li\u003e\n\u003cli\u003eSecure BMS board inside battery pack enclosure\u003c\/li\u003e\n\u003cli\u003eUse foam padding or insulation to prevent BMS from touching cells directly\u003c\/li\u003e\n\u003cli\u003eEnsure adequate ventilation around BMS (leave 5-10mm clearance)\u003c\/li\u003e\n\u003cli\u003eRoute balance wires neatly, avoid sharp bends\u003c\/li\u003e\n\u003cli\u003eKeep balance wires away from high-current main power wires\u003c\/li\u003e\n\u003cli\u003eLabel output terminals clearly: P+ (Positive) and P- (Negative)\u003c\/li\u003e\n\u003cli\u003ePerform final voltage check before sealing enclosure\u003c\/li\u003e\n\u003cli\u003eDocument your wiring for future reference\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cstrong\u003eImportant Installation Precautions \u0026amp; Safety Guidelines\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003e⚠️ CRITICAL SAFETY WARNINGS\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eBefore Installation:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e❌ \u003cstrong\u003eNEVER use this 4S BMS on 1S, 2S, 3S, or 5S+ battery packs\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003e❌ Do NOT exceed the rated current capacity of your chosen model\u003c\/li\u003e\n\u003cli\u003e❌ Do NOT reverse polarity - will destroy BMS instantly\u003c\/li\u003e\n\u003cli\u003e❌ Do NOT skip balance wire connections - BMS will not function properly\u003c\/li\u003e\n\u003cli\u003e❌ Do NOT use with Li-ion or LiPo batteries - LiFePO4 ONLY\u003c\/li\u003e\n\u003cli\u003e✅ Verify you have exactly 4 LiFePO4 cells in series\u003c\/li\u003e\n\u003cli\u003e✅ Ensure all cells are balanced (within 0.05V of each other) before installation\u003c\/li\u003e\n\u003cli\u003e✅ Select BMS current rating 20-30% higher than your maximum load\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eDuring Installation:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e❌ Never work on live circuits\u003c\/li\u003e\n\u003cli\u003e❌ Do not short circuit battery terminals with tools\u003c\/li\u003e\n\u003cli\u003e❌ Avoid touching both terminals simultaneously\u003c\/li\u003e\n\u003cli\u003e❌ Do not solder directly to battery cells (use tabs or holders)\u003c\/li\u003e\n\u003cli\u003e✅ Work methodically, one connection at a time\u003c\/li\u003e\n\u003cli\u003e✅ Use proper soldering technique (clean tip, appropriate temperature)\u003c\/li\u003e\n\u003cli\u003e✅ Insulate each connection immediately after soldering\u003c\/li\u003e\n\u003cli\u003e✅ Test each balance wire connection with multimeter before proceeding\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eBalance Wire Connection - Critical Tips:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eThe balance wires MUST be connected in the correct order\u003c\/li\u003e\n\u003cli\u003eIncorrect balance wire order will damage the BMS permanently\u003c\/li\u003e\n\u003cli\u003eLabel each wire before connecting: B-, B1, B2, B3, B+\u003c\/li\u003e\n\u003cli\u003eUse different colored wires if possible for easy identification\u003c\/li\u003e\n\u003cli\u003eStart from B- and work your way to B+ in sequence\u003c\/li\u003e\n\u003cli\u003eVerify voltage between each adjacent balance point (~3.2V)\u003c\/li\u003e\n\u003cli\u003eKeep balance wires as short as practical (but not too tight)\u003c\/li\u003e\n\u003cli\u003eDo not bundle balance wires with high-current power wires\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eWire Gauge Selection:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eUsing wire too thin will cause voltage drop and overheating\u003c\/li\u003e\n\u003cli\u003e4A model: minimum 18 AWG (1.0mm²)\u003c\/li\u003e\n\u003cli\u003e8A model: minimum 16 AWG (1.5mm²)\u003c\/li\u003e\n\u003cli\u003e10A model: minimum 14 AWG (2.5mm²)\u003c\/li\u003e\n\u003cli\u003e16A model: minimum 14 AWG (2.5mm²)\u003c\/li\u003e\n\u003cli\u003e20A model: minimum 12 AWG (4.0mm²)\u003c\/li\u003e\n\u003cli\u003eWhen in doubt, use thicker wire - it's safer\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eCommon Installation Mistakes to Avoid:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e❌ Connecting balance wires in wrong order (most common mistake)\u003c\/li\u003e\n\u003cli\u003e❌ Reversing B+ and B- connections\u003c\/li\u003e\n\u003cli\u003e❌ Using wire gauge too small for current rating\u003c\/li\u003e\n\u003cli\u003e❌ Forgetting to insulate solder joints\u003c\/li\u003e\n\u003cli\u003e❌ Mounting BMS directly against battery cells (causes shorts)\u003c\/li\u003e\n\u003cli\u003e❌ Not testing connections before final assembly\u003c\/li\u003e\n\u003cli\u003e❌ Exceeding current rating of BMS\u003c\/li\u003e\n\u003cli\u003e❌ Mixing up P+ and B+ connections\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eTroubleshooting Guide:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eNo output voltage at P+\/P-:\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003eBMS in protection mode - connect charger briefly to reset\u003c\/li\u003e\n\u003cli\u003eCheck balance wire connections are correct\u003c\/li\u003e\n\u003cli\u003eVerify battery voltage is within normal range (11V-14.6V)\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eBMS keeps shutting off under load:\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003eCurrent draw exceeds BMS rating - upgrade to higher current model\u003c\/li\u003e\n\u003cli\u003eCheck wire gauge is adequate\u003c\/li\u003e\n\u003cli\u003eVerify no short circuits in load\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eWon't charge:\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003eCheck balance wire connections\u003c\/li\u003e\n\u003cli\u003eVerify charger voltage is correct (14.6V for 4S LiFePO4)\u003c\/li\u003e\n\u003cli\u003eEnsure charger current is within BMS rating\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eBMS getting very hot:\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003eCurrent exceeds rating - reduce load or upgrade BMS\u003c\/li\u003e\n\u003cli\u003ePoor ventilation - improve airflow\u003c\/li\u003e\n\u003cli\u003eWire gauge too small - use thicker wires\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eCells not balancing:\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003eCheck all balance wire connections are secure\u003c\/li\u003e\n\u003cli\u003eVerify balance wires are in correct order\u003c\/li\u003e\n\u003cli\u003eAllow more time - balancing is slow (can take hours)\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cstrong\u003eCommon Applications for 4S 12.8V LiFePO4 BMS\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSolar Energy Systems:\u003c\/strong\u003e 12V solar battery banks, off-grid power\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRV \u0026amp; Marine:\u003c\/strong\u003e RV house batteries, boat batteries, trolling motors\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAutomotive:\u003c\/strong\u003e Car audio systems, 12V vehicle accessories\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBackup Power:\u003c\/strong\u003e UPS systems, emergency lighting, security systems\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDIY Projects:\u003c\/strong\u003e Custom 12V battery packs, portable power stations\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePower Tools:\u003c\/strong\u003e Cordless tool battery packs (12V systems)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eElectric Vehicles:\u003c\/strong\u003e Small EVs, mobility scooters, golf carts (12V systems)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLighting:\u003c\/strong\u003e LED lighting systems, camping lights\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cstrong\u003eWhy Use a BMS for LiFePO4 Batteries?\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eEssential Protection:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003ePrevents overcharging - extends battery life from 500 to 2000+ cycles\u003c\/li\u003e\n\u003cli\u003ePrevents over-discharge - protects cells from permanent damage\u003c\/li\u003e\n\u003cli\u003eBalances cells during charging - ensures all cells age evenly\u003c\/li\u003e\n\u003cli\u003eProtects against short circuits and overcurrent - prevents fires\u003c\/li\u003e\n\u003cli\u003eTemperature protection - prevents thermal damage\u003c\/li\u003e\n\u003cli\u003eRequired for safe multi-cell LiFePO4 operation\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eLong-Term Benefits:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eMaximizes battery pack lifespan (can last 10+ years with BMS)\u003c\/li\u003e\n\u003cli\u003eMaintains optimal performance throughout battery life\u003c\/li\u003e\n\u003cli\u003ePrevents costly battery replacement\u003c\/li\u003e\n\u003cli\u003eProvides peace of mind for expensive battery investments\u003c\/li\u003e\n\u003cli\u003eProtects connected devices from battery failure\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cstrong\u003eWarranty \u0026amp; Support\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eWe stand behind the quality of our BMS boards. If you experience any issues, please contact us for support. Always follow installation instructions carefully and verify all connections before applying power. \u003cstrong\u003eImproper installation, reversed polarity, or using wrong voltage configuration will void warranty.\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eNeed Help?\u003c\/strong\u003e If you're unsure about any step of the installation process, please contact us before proceeding. We're here to help ensure your battery pack is safe and reliable.\u003c\/p\u003e","brand":"fmabattery","offers":[{"title":"12.8V 4A 25.8mm","offer_id":46370429272253,"sku":"FPME04S040R492","price":8.54,"currency_code":"USD","in_stock":true},{"title":"12.8V 8A 22x50mm","offer_id":46370429305021,"sku":"FPME04S080W003","price":12.39,"currency_code":"USD","in_stock":true},{"title":"12.8V 8A 30x70mm","offer_id":46370429337789,"sku":"FPME04S080W004","price":11.67,"currency_code":"USD","in_stock":true},{"title":"12.8V 8A 16x50mm","offer_id":46370429370557,"sku":"FPME04S080W005","price":10.02,"currency_code":"USD","in_stock":true},{"title":"12.8V 10A 34x42mm","offer_id":46370429403325,"sku":"FPME04S100W006","price":12.25,"currency_code":"USD","in_stock":true},{"title":"12.8V 16A 31x62mm","offer_id":46370429436093,"sku":"FPME04S160W007","price":13.89,"currency_code":"USD","in_stock":true},{"title":"12.8V 20A 61x61mm","offer_id":46370429468861,"sku":"FPME04S200F490","price":16.98,"currency_code":"USD","in_stock":true},{"title":"12.8V 20A 34x60mm","offer_id":46370429501629,"sku":"FPME04S200W008","price":13.11,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0732\/9133\/3821\/files\/10_7ea8aca1-bafe-430b-bd29-f7f9fa0fb2eb.jpg?v=1769853417","url":"https:\/\/fmabattery.com\/products\/li-fe-battery-lifepo4-pcm-bms-12-8v-protection-circuit-management-module-board","provider":"fmabattery","version":"1.0","type":"link"}