{"id":52831,"date":"2025-05-20T18:42:11","date_gmt":"2025-05-20T17:42:11","guid":{"rendered":"https:\/\/www.microplanet.ma\/?post_type=product&#038;p=52831"},"modified":"2026-10-19T17:23:51","modified_gmt":"2026-10-19T17:23:51","slug":"4s-40a-bms-4-cell-lithium-battery-pack","status":"publish","type":"product","link":"https:\/\/www.microplanet.ma\/en\/produit\/4s-40a-bms-4-cell-lithium-battery-pack\/","title":{"rendered":"4S 40A BMS for 4-Cell Lithium Battery Packs"},"content":{"rendered":"<h3>4S 40A BMS for 4-Cell Lithium Battery Packs<\/h3>\n<p>This BMS module for four cells in series (4S) supports continuous discharge current up to 40 A and protects a 14.8 V Li-ion pack (maximum charge voltage listed as 16.8\u201318.1 V). It includes passive cell balancing to help extend battery life.<\/p>\n<h4>\ud83d\udd27 Technical specifications<\/h4>\n<ul>\n<li>Configuration: 4 cells in series (3.6 V \/ 3.7 V nominal; 16.8 V maximum charge)<\/li>\n<li>Continuous discharge current: 40 A (up to 60 A peak with suitable cooling)<\/li>\n<li>Maximum charge current: 20 A continuous (adjustable depending on version)<\/li>\n<li>Balancing current: approx. 100 mA per cell<\/li>\n<li>MOSFETs: 10 low-resistance transistors to limit losses<\/li>\n<li>Recommended charging voltage: 16.8\u201318.1 V (4 \u00d7 4.2 V)<\/li>\n<li>Built-in protection: overcharge (OVP), over-discharge (UVP), overcurrent (OCP), short circuit, reverse polarity, and over-temperature<\/li>\n<li>PCB dimensions: approx. 55 \u00d7 45 \u00d7 3.4 mm<\/li>\n<li>Operating temperature: \u221220 \u00b0C to +60 \u00b0C<\/li>\n<\/ul>\n<h4>\ud83d\udca1 Typical applications<\/h4>\n<ul>\n<li>Li-ion packs for e-bikes, electric scooters, and cordless tools<\/li>\n<li>Drones and RC models requiring high current<\/li>\n<li>Test benches and portable power supplies<\/li>\n<li>UPS systems and DIY power banks<\/li>\n<li>Arduino\/ESP32 projects powered by a 14.8 V pack<\/li>\n<\/ul>\n<h4>\ud83d\udee0\ufe0f Connections \/ pinout<\/h4>\n<table>\n<thead>\n<tr>\n<th>Pin<\/th>\n<th>Description<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td><strong>B\u2013<\/strong><\/td>\n<td>Pack negative (cell 1 negative)<\/td>\n<\/tr>\n<tr>\n<td><strong>B1<\/strong><\/td>\n<td>Junction between cell 1 and cell 2<\/td>\n<\/tr>\n<tr>\n<td><strong>B2<\/strong><\/td>\n<td>Junction between cell 2 and cell 3<\/td>\n<\/tr>\n<tr>\n<td><strong>B3<\/strong><\/td>\n<td>Junction between cell 3 and cell 4<\/td>\n<\/tr>\n<tr>\n<td><strong>B+<\/strong><\/td>\n<td>Pack positive (cell 4 positive)<\/td>\n<\/tr>\n<tr>\n<td><strong>P\u2013<\/strong><\/td>\n<td>Negative output to charger or load (usually connected to B\u2013)<\/td>\n<\/tr>\n<tr>\n<td><strong>P+<\/strong><\/td>\n<td>Positive output to charger or load (usually connected to B+)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>Connect the pack wires in this order: <strong>B\u2013 \u2192 B1 \u2192 B2 \u2192 B3 \u2192 B+<\/strong>. Then connect <strong>P\u2013 \/ P+<\/strong> to the load or charger. Always check polarity and insulation during installation.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>BMS module for four Li-ion cells in series (4S), with 40 A continuous discharge rating, passive cell balancing, and the protection functions listed below.<\/p>\n","protected":false},"featured_media":52832,"template":"","meta":[],"product_brand":[],"product_cat":[346,314,316,318],"product_tag":[],"class_list":["post-52831","product","type-product","status-publish","has-post-thumbnail","product_cat-batteries-accessoires-en","product_cat-developpement-en","product_cat-modules-capteurs-en","product_cat-alimentation-mesure-en","first","instock","sale","taxable","shipping-taxable","purchasable","product-type-simple"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v28.7 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>4S 40A BMS for 4-Cell Lithium Battery Packs | MicroPlanet<\/title>\n<meta name=\"description\" content=\"4S 40 A Li-ion BMS with 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