{"product_id":"src-jk-2699-jkbms-bd4a20s4p-7s-20s-active-balance-bms-balance-current-0-4a-continuous-current-40a-lifepo4-li-ion-lto-battery","title":"JKBMS BD4A20S4P Active Balance Battery Management System (BMS) 7S-20S, 40A, 0.4A, Bluetooth RS485","description":"\u003ch2\u003eOverview\u003c\/h2\u003e\u003cp\u003e\u003ca href=\"https:\/\/tsolar.top\/collections\/jkbms-jikong-bms\" title=\"JKBMS - JIKONG BMS\"\u003eJKBMS\u003c\/a\u003e BD4A20S4P is an active-balance Battery Management System (\u003ca href=\"https:\/\/tsolar.top\/collections\/battery-bms\" title=\"Battery BMS\"\u003eBMS\u003c\/a\u003e) for Li-ion, LiFePO4, and LTO battery packs. It supports 7S to 20S battery strings (chemistry-dependent) with 0.4A active balancing and 40A continuous charge\/discharge current, and includes built-in Bluetooth for Android\/iOS monitoring.\u003c\/p\u003e\u003ch2\u003eKey Features\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eSupported battery strings: 7S to 20S (Li-ion), 8S to 20S (LiFePO4), 12S to 20S (LTO)\u003c\/li\u003e\n\u003cli\u003eActive balance method: Active Balance (Full State On)\u003c\/li\u003e\n\u003cli\u003eBalance current: 0.4A (400mA)\u003c\/li\u003e\n\u003cli\u003eContinuous current: 40A\u003c\/li\u003e\n\u003cli\u003eMaximum discharge current (MAX 2min): 60A\u003c\/li\u003e\n\u003cli\u003ePower supply mode: the battery pack is self-powered\u003c\/li\u003e\n\u003cli\u003eBluetooth function: Bluetooth built-in; supports Android\/iOS phone\u003c\/li\u003e\n\u003cli\u003eOther interfaces: RS485 (default); CANBUS (customized option)\u003c\/li\u003e\n\u003cli\u003eWiring method \/ wiring output: same port \/ common port\u003c\/li\u003e\n\u003cli\u003eSupport: short circuit protection; single cell voltage dropout detection; temperature protection; coulomb counter\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eFor wiring guidance, communication integration, or app support, contact \u003ca href=\"https:\/\/tsolar.top\/\" rel=\"nofollow\"\u003ehttps:\/\/tsolar.top\/\u003c\/a\u003e or email service@tsolar.top.\u003c\/p\u003e\u003ch2\u003eSpecifications\u003c\/h2\u003e\u003ctable\u003e\n\u003ctr\u003e\n\u003ctd\u003eModel\u003c\/td\u003e\n\u003ctd\u003eBD4A20S4P\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNumber of Battery Strings (Li-ion)\u003c\/td\u003e\n\u003ctd\u003e7S-20S\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNumber of Battery Strings (LiFePO4)\u003c\/td\u003e\n\u003ctd\u003e8S-20S\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNumber of Battery Strings (LTO)\u003c\/td\u003e\n\u003ctd\u003e12S-20S\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBalance Method\u003c\/td\u003e\n\u003ctd\u003eActive Balance (Full State On)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBalance Current\u003c\/td\u003e\n\u003ctd\u003e0.4A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eContinuous Charge Current\u003c\/td\u003e\n\u003ctd\u003e40A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eContinuous Discharge Current\u003c\/td\u003e\n\u003ctd\u003e40A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMaximum Discharge Current (MAX 2min)\u003c\/td\u003e\n\u003ctd\u003e60A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOver Charge Protection Current (ADJ)\u003c\/td\u003e\n\u003ctd\u003e10-40A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eConductive Resistance in Main Circuit\u003c\/td\u003e\n\u003ctd\u003e2.8mΩ\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSize\u003c\/td\u003e\n\u003ctd\u003e110*73*18mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWiring Output\u003c\/td\u003e\n\u003ctd\u003eCommon Port\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSingle Cell Voltage Range\u003c\/td\u003e\n\u003ctd\u003e1-5V\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSingle Cell Voltage Detection Range\u003c\/td\u003e\n\u003ctd\u003e0-5V; error \u0026lt; 10mV over full operating range; typical error value \u0026lt; 5mV\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eVoltage Acquisition Accuracy\u003c\/td\u003e\n\u003ctd\u003e±5mV\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTotal Voltage Detection Range\u003c\/td\u003e\n\u003ctd\u003e0-100V; \u0026lt; 0.5%FSR (FSR = full scale)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCurrent Sense Shunt\u003c\/td\u003e\n\u003ctd\u003e-150A to 300A; error \u0026lt; 0.5%FSR\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSoC Estimation Accuracy\u003c\/td\u003e\n\u003ctd\u003eError \u0026lt; 8% (operating conditions)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBattery Remaining Capacity\u003c\/td\u003e\n\u003ctd\u003eError range is less than 8%\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTotal Cycle AH Cumulative Value\u003c\/td\u003e\n\u003ctd\u003eHalf of the charge\/discharge value\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOver Charge Protection Voltage\u003c\/td\u003e\n\u003ctd\u003e1.2-4.35V adjustable\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOver Charge Release Voltage\u003c\/td\u003e\n\u003ctd\u003e1.2-4.35V adjustable\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOver Discharge Protection Voltage\u003c\/td\u003e\n\u003ctd\u003e1.2-4.35V adjustable\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOver Discharge Release Voltage\u003c\/td\u003e\n\u003ctd\u003e1.2-4.35V adjustable\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOver Current Detect Delay\u003c\/td\u003e\n\u003ctd\u003e2-120S adjustable\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eQuantity of Temperature Detection\u003c\/td\u003e\n\u003ctd\u003e3Pcs\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTemperature Detection\u003c\/td\u003e\n\u003ctd\u003e-40 to 125°C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOperating Temperature\u003c\/td\u003e\n\u003ctd\u003e-40 to 85°C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eStoring Temperature\u003c\/td\u003e\n\u003ctd\u003e-40 to 95°C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOperating Power Consumption\u003c\/td\u003e\n\u003ctd\u003e\u0026lt; 5mA (without communication) \/ 15mA (485\/CAN)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eStandby Power Consumption\u003c\/td\u003e\n\u003ctd\u003e\u0026lt; 2mA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOther Interfaces (Default)\u003c\/td\u003e\n\u003ctd\u003eRS485\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOther Interfaces (Customized)\u003c\/td\u003e\n\u003ctd\u003eCANBUS\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBluetooth Function\u003c\/td\u003e\n\u003ctd\u003eSupport for Android \u0026amp; iOS phone\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTemp Protection\u003c\/td\u003e\n\u003ctd\u003eYES\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eShort Circuit Protection\u003c\/td\u003e\n\u003ctd\u003eYES\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCoulomb Counter\u003c\/td\u003e\n\u003ctd\u003eYES\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\u003ch2\u003eInterfaces and Port Labels (from images)\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eCANBUS (need customization): GND, CAN_H, CAN_L\u003c\/li\u003e\n\u003cli\u003eRS485 (by default): GND, RX, TX, VCC\u003c\/li\u003e\n\u003cli\u003eLCD (by default): K-, K+, GND, B, A, VCC\u003c\/li\u003e\n\u003cli\u003eHeat Function (need customization): labeled as Heat Function\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eProtection Items (Six Security Protection)\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eOver charge protection: Prevent over-charging affects battery life\u003c\/li\u003e\n\u003cli\u003eShort circuit protection: Automatic protection when short circuit protection\u003c\/li\u003e\n\u003cli\u003eOver discharge protection: Prevent the battery from running out\u003c\/li\u003e\n\u003cli\u003eOver current protection: Prevent the current from exceeding the battery range\u003c\/li\u003e\n\u003cli\u003eALL-IN protection: Prevent cable drop or poor contact\u003c\/li\u003e\n\u003cli\u003eOver temp protection: Prevent the battery from over heating\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eSmart Energy Working Mode Switching (text from images)\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eStorage Mode\u003c\/strong\u003e: In transportation, storage, offline or wireless transmission off mode, the BMS is in storage mode, which does not consume battery pack current.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNormal Working Mode\u003c\/strong\u003e: When the charger is inserted in the storage mode and off mode, the BMS will immediately return to the normal working mode, and all the protection functions, equalization functions and communication functions will return to normal working.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eShutdown\u003c\/strong\u003e: To prevent the BMS from wasting power for a long time and damaging the battery pack, the BMS has an automatic shutdown voltage, and the BMS automatically shuts down when a cell falls below the shutdown voltage.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStandby Mode\u003c\/strong\u003e: When the battery pack is in the static state (no charge and discharge current and no equilibrium current), the BMS will automatically enter the standby state after the set time (1-30 days can be set) is exceeded.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eBluetooth App Notes (text from description)\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eDownload the specified Bluetooth application and activate the BMS.\u003c\/li\u003e\n\u003cli\u003eOpen the Bluetooth application and find the relevant serial number, then you can check all the data.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eApplications\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eBattery pack management for Li-ion (7S-20S), LiFePO4 (8S-20S), and LTO (12S-20S)\u003c\/li\u003e\n\u003cli\u003eSystems requiring active balancing and Bluetooth monitoring\u003c\/li\u003e\n\u003cli\u003eInstallations using RS485 (default) or CANBUS (customized option)\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eImage Text (Other Models Shown in Provided Images)\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eJK-BD6A17S6P: Active Balance BMS; Active Balance Current 0.6A; Adapt Battery Strings: 10S-17S (LTO), 7S-17S (Li-ion), 8S-17S (Lifepo4); Continuous Discharge\/Charge Current 60A.\u003c\/li\u003e\n\u003cli\u003eJK-B2A20S20P-H-C: Active Balance BMS; Active Balance Current 2A; Adapt Battery Strings: 10S-20S (LTO), 7S-20S (Li-ion), 8S-20S (Lifepo4); Continuous Discharge\/Charge Current 200A; Support Batteries Heating Function \/ built-in heating chip; Support RS485 Function Default \/ built-in CANBUS chip.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2 id=\"details\"\u003eDetails\u003c\/h2\u003e\u003cdiv class=\"details-gallery\"\u003e\n\u003cimg alt=\"JKBMS smart active-balance BMS module banner with Bluetooth icon and product board with wiring leads\" loading=\"lazy\" src=\"https:\/\/tsolar.top\/cdn\/shop\/files\/JKBMS-BD4A20S4P-7S-20S-Active-Balance-BMS-Balance-Current.jpg?v=1780114935\"\u003e\u003cp\u003eBuilt-in Bluetooth enables real-time pack monitoring and settings from an Android or iOS phone.\u003c\/p\u003e\n\u003cimg alt=\"JKBMS active balance BMS banner showing model text, supported battery strings, and RS485\/CAN communication options\" loading=\"lazy\" src=\"https:\/\/tsolar.top\/cdn\/shop\/files\/JKBMS-BD4A20S4P-7S-20S-Active-Balance-BMS-Balance-Current_2ac9290c-0843-49bd-8790-bfcf39bf03c8.jpg?v=1780114941\"\u003e\u003cp\u003eRS485 communication comes standard, with CANBUS available as a customized option for system integration.\u003c\/p\u003e\n\u003cimg alt=\"Exploded view of the JKBMS active-balance BMS showing enclosure, circuit boards, and main power connections\" loading=\"lazy\" src=\"https:\/\/tsolar.top\/cdn\/shop\/files\/JKBMS-BD4A20S4P-7S-20S-Active-Balance-BMS-Balance-Current.png?v=1780114948\"\u003e\u003cp\u003eA compact layered design protects the electronics while keeping wiring and service access straightforward.\u003c\/p\u003e\n\u003cimg alt=\"connector pinout close-up labeled for CANBUS, RS485, LCD\/GPS, and optional heating function connections\" loading=\"lazy\" src=\"https:\/\/tsolar.top\/cdn\/shop\/files\/JKBMS-BD4A20S4P-7S-20S-Active-Balance-BMS-Balance-Current_4e782634-28c5-4e79-967a-06feb6828436.jpg?v=1780114956\"\u003e\u003cp\u003eClear port labeling helps with correct wiring for RS485\/CAN communication, display\/GPS connections, and optional functions.\u003c\/p\u003e\n\u003cimg alt=\"Smartphone screen with battery monitoring app showing pack voltage, current, SOC, and per-cell voltages\" loading=\"lazy\" src=\"https:\/\/tsolar.top\/cdn\/shop\/files\/JKBMS-BD4A20S4P-7S-20S-Active-Balance-BMS-Balance-Current_60dff76d-52a0-4123-925f-e4098170bf93.jpg?v=1780114963\"\u003e\u003cp\u003eThe mobile app displays total voltage, charge\/discharge current, state of charge, and individual cell readings at a glance.\u003c\/p\u003e\n\u003cimg alt=\"app screenshots showing device list, chemistry selection (Li-ion\/LiFePO4\/LTO), and cell voltage\/resistance data\" loading=\"lazy\" src=\"https:\/\/tsolar.top\/cdn\/shop\/files\/JKBMS-BD4A20S4P-7S-20S-Active-Balance-BMS-Balance-Current_69a8d8dd-1858-4a6f-aa1e-c7cb3444ab7d.jpg?v=1780114969\"\u003e\u003cp\u003eChemistry selection and detailed cell data support commissioning for Li-ion, LiFePO4, or LTO packs.\u003c\/p\u003e\n\u003cimg alt=\"Infographic listing six protections: overcharge, short circuit, overdischarge, overcurrent, cable drop, overtemp\" loading=\"lazy\" src=\"https:\/\/tsolar.top\/cdn\/shop\/files\/JKBMS-BD4A20S4P-7S-20S-Active-Balance-BMS-Balance-Current_43136c64-5460-497b-abcb-11e65a78f32e.jpg?v=1780114976\"\u003e\u003cp\u003eProtection features cover common fault conditions including over\/under-voltage, short circuit, overcurrent, and over-temperature.\u003c\/p\u003e\n\u003cimg alt=\"Smart energy working mode switching chart for : storage, normal working, standby, and shutdown modes\" loading=\"lazy\" src=\"https:\/\/tsolar.top\/cdn\/shop\/files\/JKBMS-BD4A20S4P-7S-20S-Active-Balance-BMS-Balance-Current_6d1ade4c-5d31-4004-b5ce-0f871767ca89.jpg?v=1780114984\"\u003e\u003cp\u003eMultiple power modes help reduce standby drain during storage while returning to normal operation when charging resumes.\u003c\/p\u003e\n\u003cimg alt=\"specification comparison table listing battery string ranges, balance current, current ratings, and interfaces by model\" loading=\"lazy\" src=\"https:\/\/tsolar.top\/cdn\/shop\/files\/JKBMS-BD4A20S4P-7S-20S-Active-Balance-BMS-Balance-Current_4077cdf6-57f4-41b6-9556-dfe92bff6b21.jpg?v=1780114992\"\u003e\u003cp\u003eUse the model comparison table to match string count, balancing current, and current rating to your battery pack requirements.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"JIKONG","offers":[{"title":"Default Title","offer_id":52312356389138,"sku":"jk-2699-","price":53.07,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0863\/2860\/6994\/files\/BD4A20S4P-1-JKBMS-7S-17S-20S-24S-Active-Balance-BMS-Balance-Current-0.4A-0.6A-Continuous-Current-40A-60A-80A-Lifepo4-li-ion-LTO-Battery.jpg?v=1780067842","url":"https:\/\/tsolar.top\/products\/src-jk-2699-jkbms-bd4a20s4p-7s-20s-active-balance-bms-balance-current-0-4a-continuous-current-40a-lifepo4-li-ion-lto-battery","provider":"TSolar","version":"1.0","type":"link"}