{"id":7232,"date":"2022-02-10T16:54:58","date_gmt":"2022-02-10T15:54:58","guid":{"rendered":"https:\/\/onvolt.pl\/parallel-connection-of-lithium-batteries\/"},"modified":"2025-04-07T12:45:14","modified_gmt":"2025-04-07T10:45:14","slug":"parallel-connection-of-lithium-batteries","status":"publish","type":"post","link":"https:\/\/onvolt.pl\/en\/parallel-connection-of-lithium-batteries\/","title":{"rendered":"Parallel connection of lithium batteries"},"content":{"rendered":"<p>[et_pb_section fb_built=&#8221;1&#8243; _builder_version=&#8221;4.16&#8243; vertical_offset_tablet=&#8221;0&#8243; horizontal_offset_tablet=&#8221;0&#8243; custom_padding=&#8221;0px||||false|false&#8221; box_shadow_horizontal_tablet=&#8221;0px&#8221; box_shadow_vertical_tablet=&#8221;0px&#8221; box_shadow_blur_tablet=&#8221;40px&#8221; box_shadow_spread_tablet=&#8221;0px&#8221; global_colors_info=&#8221;{}&#8221; theme_builder_area=&#8221;post_content&#8221;][et_pb_row _builder_version=&#8221;4.16&#8243; background_size=&#8221;initial&#8221; background_position=&#8221;top_left&#8221; background_repeat=&#8221;repeat&#8221; global_colors_info=&#8221;{}&#8221; theme_builder_area=&#8221;post_content&#8221;][et_pb_column type=&#8221;4_4&#8243; _builder_version=&#8221;4.16&#8243; custom_padding=&#8221;|||&#8221; global_colors_info=&#8221;{}&#8221; custom_padding__hover=&#8221;|||&#8221; theme_builder_area=&#8221;post_content&#8221;][et_pb_text admin_label=&#8221;Tekst&#8221; _builder_version=&#8221;4.27.0&#8243; text_text_color=&#8221;#000000&#8243; vertical_offset_tablet=&#8221;0&#8243; horizontal_offset_tablet=&#8221;0&#8243; z_index_tablet=&#8221;0&#8243; text_text_shadow_horizontal_length_tablet=&#8221;0px&#8221; text_text_shadow_vertical_length_tablet=&#8221;0px&#8221; text_text_shadow_blur_strength_tablet=&#8221;1px&#8221; link_text_shadow_horizontal_length_tablet=&#8221;0px&#8221; link_text_shadow_vertical_length_tablet=&#8221;0px&#8221; link_text_shadow_blur_strength_tablet=&#8221;1px&#8221; ul_text_shadow_horizontal_length_tablet=&#8221;0px&#8221; ul_text_shadow_vertical_length_tablet=&#8221;0px&#8221; ul_text_shadow_blur_strength_tablet=&#8221;1px&#8221; ol_text_shadow_horizontal_length_tablet=&#8221;0px&#8221; ol_text_shadow_vertical_length_tablet=&#8221;0px&#8221; ol_text_shadow_blur_strength_tablet=&#8221;1px&#8221; quote_text_shadow_horizontal_length_tablet=&#8221;0px&#8221; quote_text_shadow_vertical_length_tablet=&#8221;0px&#8221; quote_text_shadow_blur_strength_tablet=&#8221;1px&#8221; header_text_shadow_horizontal_length_tablet=&#8221;0px&#8221; header_text_shadow_vertical_length_tablet=&#8221;0px&#8221; header_text_shadow_blur_strength_tablet=&#8221;1px&#8221; header_2_text_shadow_horizontal_length_tablet=&#8221;0px&#8221; header_2_text_shadow_vertical_length_tablet=&#8221;0px&#8221; header_2_text_shadow_blur_strength_tablet=&#8221;1px&#8221; header_3_text_shadow_horizontal_length_tablet=&#8221;0px&#8221; header_3_text_shadow_vertical_length_tablet=&#8221;0px&#8221; header_3_text_shadow_blur_strength_tablet=&#8221;1px&#8221; header_4_text_shadow_horizontal_length_tablet=&#8221;0px&#8221; header_4_text_shadow_vertical_length_tablet=&#8221;0px&#8221; header_4_text_shadow_blur_strength_tablet=&#8221;1px&#8221; header_5_text_shadow_horizontal_length_tablet=&#8221;0px&#8221; header_5_text_shadow_vertical_length_tablet=&#8221;0px&#8221; header_5_text_shadow_blur_strength_tablet=&#8221;1px&#8221; header_6_text_shadow_horizontal_length_tablet=&#8221;0px&#8221; header_6_text_shadow_vertical_length_tablet=&#8221;0px&#8221; header_6_text_shadow_blur_strength_tablet=&#8221;1px&#8221; box_shadow_horizontal_tablet=&#8221;0px&#8221; box_shadow_vertical_tablet=&#8221;0px&#8221; box_shadow_blur_tablet=&#8221;40px&#8221; box_shadow_spread_tablet=&#8221;0px&#8221; global_colors_info=&#8221;{}&#8221; theme_builder_area=&#8221;post_content&#8221;]<\/p>\n<p><span style=\"color: #000000;\">\u200bWhen using standard BMS, parallel connection of lithium batteries is not allowed due to the very probable damage to the BMS electronics (which may result in damage to the cells). This is the result of uncontrolled current flow between batteries due to the difference in voltage and internal resistance.<\/span><\/p>\n<p><span style=\"color: #000000;\">This situation occurs when several batteries with different levels of charge are connected, or when a cell is damaged during operation, in any of them.<\/span><\/p>\n<p><span style=\"color: #000000;\">Damage to the BMS and cells caused by their operation in parallel systems is excluded from the manufacturer&#8217;s warranty.<\/span><\/p>\n<p><span style=\"color: #000000;\">Nevertheless, the parallel connection is a very interesting alternative to using a single, very large battery, especially in energy storage systems.<\/span><\/p>\n<p><span style=\"color: #000000;\">It allows you to increase the capacity of the power bank, as well as doubling the allowable discharge current, and therefore the power that can be drawn.<\/span><\/p>\n<p><span style=\"color: #000000;\"> <\/span><\/p>\n<p><span style=\"color: #000000;\">To solve this problem, Daly has developed an additional device &#8211; a<strong>parallel<\/strong> module &#8211; to control and limit the current flowing between the batteries.<\/span><\/p>\n<p><span style=\"color: #000000;\">Parallel module is a device that allows parallel connection of lithium batteries (equipped with BMS).<\/span><\/p>\n<p><span style=\"color: #000000;\">The principle of the module&#8217;s operation boils down to disconnecting the BMS when the difference in battery voltages causes a current flow of a value greater than that limited by the module. During this time, current flows between batteries only through the module and is limited to a safe value of 5 or 15A. Once the voltages are equalized, the module reconnects the BMS.<\/span><\/p>\n<p><span style=\"color: #000000;\"> <\/span><\/p>\n<p><span style=\"color: #000000;\">For safe parallel connection of lithium batteries, the following conditions must be met:<\/span><\/p>\n<ul>\n<li><span style=\"color: #000000;\">All combined batteries must be made of identical cells (type, capacity, manufacturer) and have a similar degree of wear.<\/span><\/li>\n<li><span style=\"color: #000000;\">Each battery must be equipped with the same BMS and a matching parallel module.<\/span><\/li>\n<li><span style=\"color: #000000;\">It is good practice to combine batteries when they are in a similar state of charge.<\/span><\/li>\n<\/ul>\n<p><span style=\"color: #000000;\"> <\/span><\/p>\n<p><span style=\"color: #000000;\">For proper operation of the module, it is required to use a BMS of the series that allows such cooperation. They can be recognized by the presence of an output with the marking &#8220;Parallel&#8221; on the housing.<\/span><\/p>\n<p><span style=\"color: #000000;\">Since parallel modules are made in several current versions (usually 5A or 15A) the BMS used must have software adapted to the specific version of the module.<\/span><\/p>\n<p><span style=\"color: #000000;\">In the BMS imported by Onvolt, BMS SMART versions up to 100A are adapted to 5A modules, and BMS versions from 150A to 15A modules.<\/span><\/p>\n<p><span style=\"color: #000000;\">The only difference in performance between the 5A and 15A versions of the modules is the time it takes to equalize battery voltages after connection.<\/span><\/p>\n<p><span style=\"color: #000000;\">In special cases, it is possible to order BMS with currents below 100A adapted to work with 15A modules.<\/span><\/p>\n<p><span style=\"color: #000000;\">Connecting the wrong module to the BMS will result in malfunction of the system.<\/span><\/p>\n<p>[\/et_pb_text][et_pb_gallery gallery_ids=&#8221;10567,10569&#8243; show_title_and_caption=&#8221;off&#8221; admin_label=&#8221;Galeria&#8221; _builder_version=&#8221;4.21.0&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221; theme_builder_area=&#8221;post_content&#8221;][\/et_pb_gallery][et_pb_text _builder_version=&#8221;4.27.0&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221; theme_builder_area=&#8221;post_content&#8221;]<\/p>\n<ol>\n<li><span style=\"color: #000000;\"><strong>Characteristics<\/strong><\/span><\/li>\n<\/ol>\n<ul>\n<li><span style=\"color: #000000;\">Easy installation<\/span><\/li>\n<li><span style=\"color: #000000;\">Good insulation, stable current, high safety<\/span><\/li>\n<li><span style=\"color: #000000;\">Performed safety tests to exacting standards<\/span><\/li>\n<li><span style=\"color: #000000;\">The case with modern design is completely resistant to moisture, dust, provides mechanical resistance and proper cooling.<\/span><\/li>\n<\/ul>\n<ol start=\"2\">\n<li><span style=\"color: #000000;\"><strong>Main parameters<\/strong><\/span><\/li>\n<\/ol>\n<table width=\"547\">\n<tbody>\n<tr>\n<td width=\"149\"><\/td>\n<td width=\"227\"><span style=\"color: #000000;\">MR 15A<\/span><\/td>\n<td width=\"171\"><span style=\"color: #000000;\">MR 5A<\/span><\/td>\n<\/tr>\n<tr>\n<td width=\"149\"><span style=\"color: #000000;\">External dimensions<br \/>\n<\/span><\/td>\n<td width=\"227\"><span style=\"color: #000000;\">174x66x44mm<\/span><\/td>\n<td width=\"171\"><span style=\"color: #000000;\">104x49x21mm<\/span><\/td>\n<\/tr>\n<tr>\n<td width=\"149\"><span style=\"color: #000000;\">Current limit<br \/>\n<\/span><\/td>\n<td width=\"227\"><span style=\"color: #000000;\">15A<\/span><\/td>\n<td width=\"171\"><span style=\"color: #000000;\">5A<\/span><\/td>\n<\/tr>\n<tr>\n<td width=\"149\"><span style=\"color: #000000;\">Module activation<br \/>\n<\/span><\/td>\n<td colspan=\"2\" width=\"397\"><span style=\"color: #000000;\">maximum current between batteries exceeded<\/span><\/td>\n<\/tr>\n<tr>\n<td width=\"149\"><span style=\"color: #000000;\">Operating temperature<br \/>\n<\/span><\/td>\n<td colspan=\"2\" width=\"397\"><span style=\"color: #000000;\">-20~70\u00b0C<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><span style=\"color: #000000;\"> <\/span><\/p>\n<p>[\/et_pb_text][et_pb_gallery gallery_ids=&#8221;10571&#8243; _builder_version=&#8221;4.21.0&#8243; _module_preset=&#8221;default&#8221; global_colors_info=&#8221;{}&#8221; theme_builder_area=&#8221;post_content&#8221;][\/et_pb_gallery][\/et_pb_column][\/et_pb_row][\/et_pb_section]<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u200bWhen using standard BMS, parallel connection of lithium batteries is not allowed due to the very probable damage to the BMS electronics (which may result in damage to the cells). This is the result of uncontrolled current flow between batteries due to the difference in voltage and internal resistance. This situation occurs when several batteries [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":9265,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_et_pb_use_builder":"on","_et_pb_old_content":"","_et_gb_content_width":"","footnotes":""},"categories":[1797],"tags":[],"class_list":["post-7232","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-cells-information-operation"],"_links":{"self":[{"href":"https:\/\/onvolt.pl\/en\/wp-json\/wp\/v2\/posts\/7232","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/onvolt.pl\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/onvolt.pl\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/onvolt.pl\/en\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/onvolt.pl\/en\/wp-json\/wp\/v2\/comments?post=7232"}],"version-history":[{"count":7,"href":"https:\/\/onvolt.pl\/en\/wp-json\/wp\/v2\/posts\/7232\/revisions"}],"predecessor-version":[{"id":26027,"href":"https:\/\/onvolt.pl\/en\/wp-json\/wp\/v2\/posts\/7232\/revisions\/26027"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/onvolt.pl\/en\/wp-json\/wp\/v2\/media\/9265"}],"wp:attachment":[{"href":"https:\/\/onvolt.pl\/en\/wp-json\/wp\/v2\/media?parent=7232"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/onvolt.pl\/en\/wp-json\/wp\/v2\/categories?post=7232"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/onvolt.pl\/en\/wp-json\/wp\/v2\/tags?post=7232"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}