{"id":20489,"date":"2026-10-31T10:22:42","date_gmt":"2026-10-31T02:22:42","guid":{"rendered":"https:\/\/www.wehopower.com\/news\/sc-120-12-load-charging-current-budget\/"},"modified":"2026-10-31T10:22:42","modified_gmt":"2026-10-31T02:22:42","slug":"sc-120-12-load-charging-current-budget","status":"publish","type":"news","link":"https:\/\/www.wehopower.com\/bn\/news\/sc-120-12-load-charging-current-budget\/","title":{"rendered":"SC-120-12 Switching Power Supply: Load and Charging Budgets"},"content":{"rendered":"<div class=\"weho-blog-content\">\n<p><strong>For an SC-120-12 switching power supply review, budget the equipment load and battery-charging path separately.<\/strong> A lightly loaded main output does not establish extra charging current, and a charge-current figure cannot be added to the load-output rating. The purchasing decision needs two current budgets plus evidence of what happens while the battery reserve is restored.<\/p>\n<p>This workflow is for an OEM reviewing a 12 V battery-backed assembly. Its deliverable is a channel-by-channel load sheet and a recovery acceptance record. Runtime selection and the choice between hold-up, a buffer and a DC UPS are separate decisions.<\/p>\n<details class=\"article-toc\" open>\n<summary>On this page<\/summary>\n<ol class=\"toc-list\">\n<li><a href=\"#identify-12v-variant\">Start with the SC-120-12 variant<\/a><\/li>\n<li><a href=\"#two-current-budgets\">Calculate two budgets at the same operating point<\/a><\/li>\n<li><a href=\"#recovery-evidence\">Turn a charging number into a recovery requirement<\/a><\/li>\n<li><a href=\"#recovery-record\">Request a repeatable recovery record<\/a><\/li>\n<\/ol>\n<\/details>\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_86 counter-hierarchy ez-toc-counter ez-toc-grey ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">\u09b8\u09c2\u099a\u09bf\u09aa\u09a4\u09cd\u09b0<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">\u099f\u0997\u09b2 \u0995\u09b0\u09c1\u09a8<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewbox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewbox=\"0 0 24 24\" version=\"1.2\" baseprofile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/www.wehopower.com\/bn\/news\/sc-120-12-load-charging-current-budget\/#Start_with_the_SC-120-12_variant\" >Start with the SC-120-12 variant<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/www.wehopower.com\/bn\/news\/sc-120-12-load-charging-current-budget\/#Calculate_two_budgets_at_the_same_operating_point\" >Calculate two budgets at the same operating point<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/www.wehopower.com\/bn\/news\/sc-120-12-load-charging-current-budget\/#Turn_a_charging_number_into_a_recovery_requirement\" >Turn a charging number into a recovery requirement<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/www.wehopower.com\/bn\/news\/sc-120-12-load-charging-current-budget\/#Request_a_repeatable_recovery_record\" >Request a repeatable recovery record<\/a><\/li><\/ul><\/nav><\/div>\n<h2 id=\"identify-12v-variant\"><span class=\"ez-toc-section\" id=\"Start_with_the_SC-120-12_variant\"><\/span>Start with the SC-120-12 variant<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>\u09a6 <a href=\"https:\/\/www.wehopower.com\/wp-content\/uploads\/2021\/11\/SC-120ok.pdf\">published WEHO SC-120 specification<\/a> lists SC-120-12 with CH1 at <strong>13.8 V, 8.0 A<\/strong> and CH2 at <strong>13.4 V, 0.50 A<\/strong>. Its 24 V variant has different values. Keep the full suffix on the load sheet and match it to the delivered unit and applicable document revision.<\/p>\n<figure class=\"product-reference product-scene\" id=\"figure-sc-120-12-product\"><a class=\"product-image scene-product-image\" href=\"https:\/\/www.wehopower.com\/bn\/product\/ups-120w-ac-to-dc-single-output-power-supply-for-battery-charge\/\" aria-label=\"SC-120-12 product details\"><img loading=\"lazy\" src=\"https:\/\/www.wehopower.com\/wp-content\/uploads\/2026\/10\/74-sc-120-12-product-scene-alpha-v10.jpg\" width=\"1254\" height=\"1254\" alt=\"SC-120-12 Switching Power Supply: Load and Charging Budgets  title=\" decoding=\"async\" sc-120-12 switching power supply: load and charging budgets title =\"\"><\/a><figcaption>Application illustration; exact original product photograph retained, environment AI-assisted, not a customer installation or test. SC-120-12 retains its original enclosure, terminal row and loose leads. Unconnected background bench items are generic illustration props; no battery chemistry compatibility, wiring connection or charging performance is depicted.<\/figcaption><div class=\"image-actions\"><a href=\"https:\/\/www.wehopower.com\/wp-content\/uploads\/2026\/10\/74-sc-120-12-product-original.jpg\">View unchanged original product photograph<\/a><a href=\"https:\/\/www.wehopower.com\/wp-content\/uploads\/2026\/10\/74-sc-120-12-product-scene-alpha-v10.jpg\">View full-size application illustration<\/a><a href=\"https:\/\/www.wehopower.com\/bn\/product\/ups-120w-ac-to-dc-single-output-power-supply-for-battery-charge\/\">SC-120-12 product details<\/a><a href=\"https:\/\/www.wehopower.com\/wp-content\/uploads\/2026\/10\/74-sc-120-12-product-scene-alpha-v10-layers.svg\">Inspect illustration layers (SVG)<\/a><a href=\"https:\/\/www.wehopower.com\/wp-content\/uploads\/2021\/11\/SC-120ok.pdf\">SC-120-12 documentation<\/a><\/div>\n<\/figure>\n<p>A nominal \u201c12 V\u201d device must accept the actual voltage presented in each operating state. Check the receiving equipment\u2019s allowed range, cable drop and battery-mode behavior. The listed CH1 voltage does not prove that the output remains at 13.8 V throughout a battery discharge.<\/p>\n<div class=\"weho-table-wrap\" tabindex=\"0\" role=\"region\" aria-label=\"Scrollable article table\">\n<table>\n<caption>SC-120-12 entries in the published specification; confirm the applicable revision<\/caption>\n<thead>\n<tr>\n<th scope=\"col\">Record<\/th>\n<th scope=\"col\">Listed value<\/th>\n<th scope=\"col\">Use in the review<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>CH1<\/td>\n<td>13.8 V; 8.0 A<\/td>\n<td>Separate equipment-load budget<\/td>\n<\/tr>\n<tr>\n<td>CH2<\/td>\n<td>13.4 V; 0.50 A<\/td>\n<td>Separate charging-path inquiry<\/td>\n<\/tr>\n<tr>\n<td>Rated power<\/td>\n<td>117.1 W<\/td>\n<td>Check channel allocation and operating conditions together<\/td>\n<\/tr>\n<tr>\n<td>Input selection<\/td>\n<td>90\u2013132 \/ 180\u2013264 VAC, selected by switch<\/td>\n<td>Match the input setting and applicable installation instructions<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<h2 id=\"two-current-budgets\"><span class=\"ez-toc-section\" id=\"Calculate_two_budgets_at_the_same_operating_point\"><\/span>Calculate two budgets at the same operating point<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><strong>Hypothetical load schedule:<\/strong> electronics need 2.6 A, communications 2.1 A and auxiliary devices 1.3 A simultaneously. CH1 demand is therefore 6.0 A. At an assumed 13.8 V, that equals <strong>82.8 W<\/strong>. If startup adds 1.2 A, the example reaches 7.2 A, or 99.36 W, during that defined event.<\/p>\n<p>For a separate illustrative charging demand of 0.50 A at 13.4 V, charging power is 6.7 W. The arithmetic totals are 89.5 W during steady operation and 106.06 W during the example startup. These are calculated screening points, not measured SC-120 results or a product selection.<\/p>\n<figure class=\"article-relation concept-diagram\" id=\"figure-separate-channel-budgets\"><a href=\"https:\/\/www.wehopower.com\/wp-content\/uploads\/2026\/10\/74-separate-channel-budgets-v10.svg\" aria-label=\"Open full-size Keep two channel budgets diagram\"><picture><source media=\"(max-width:640px)\" srcset=\"https:\/\/www.wehopower.com\/wp-content\/uploads\/2026\/10\/74-separate-channel-budgets-v10-mobile.svg\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/www.wehopower.com\/wp-content\/uploads\/2026\/10\/74-separate-channel-budgets-v10.svg\" width=\"1200\" height=\"519\" alt=\"SC-120-12 Switching Power Supply: Load and Charging Budgets  title=\" sc-120-12 switching power supply: load and charging budgets title =\"\"><\/picture><\/a><figcaption>Concept budget structure; not a connection diagram or a measured result.<\/figcaption><a class=\"diagram-original\" href=\"https:\/\/www.wehopower.com\/wp-content\/uploads\/2026\/10\/74-separate-channel-budgets-v10.svg\">Open full-size diagram<\/a><\/figure>\n<p>The sheet\u2019s 117.1 W equals 13.8 \u00d7 8.0 + 13.4 \u00d7 0.50. That arithmetic reproduces the listed entries; it does not establish every permissible load\/charge combination, transient or environmental condition. Ask which simultaneous conditions the current revision supports. Keep any unused CH1 capacity separate from the charging allocation.<\/p>\n<p>The specification includes a derating curve. Compare the intended local temperature, input and installation with that curve rather than applying a full-power assumption across the working-temperature range. Record startup duration and repetition separately from continuous demand.<\/p>\n<h2 id=\"recovery-evidence\"><span class=\"ez-toc-section\" id=\"Turn_a_charging_number_into_a_recovery_requirement\"><\/span>Turn a charging number into a recovery requirement<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Specify the approved battery type, capacity, operating temperature and charging instructions before agreeing on recovery time. A voltage label alone does not establish battery-chemistry compatibility, an appropriate charging profile or a full-charge endpoint.<\/p>\n<p><strong>Illustrative arithmetic only:<\/strong> replacing a 0.25 Ah charge deficit at a constant 0.50 A would take 0.25 \u00f7 0.50 = <strong>0.50 hours<\/strong>. That simplified 30-minute result assumes constant current and no losses or taper. It is not a promised recharge time. Actual recovery needs the battery and charging-system data and a defined readiness criterion.<\/p>\n<p>Ask for evidence with the equipment still operating during recovery. Define whether \u201cready\u201d means a particular state of charge, a measured reserve sufficient for the next event, or another validated system criterion. An indicator alone needs a documented meaning before it can establish readiness.<\/p>\n<h2 id=\"recovery-record\"><span class=\"ez-toc-section\" id=\"Request_a_repeatable_recovery_record\"><\/span>Request a repeatable recovery record<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<div class=\"weho-table-wrap\" tabindex=\"0\" role=\"region\" aria-label=\"Scrollable article table\">\n<table>\n<thead>\n<tr>\n<th scope=\"col\">State to record<\/th>\n<th scope=\"col\">Required evidence<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Normal supply and charging<\/td>\n<td>CH1 load, charging current, both relevant voltages, input and local temperature<\/td>\n<\/tr>\n<tr>\n<td>Input loss<\/td>\n<td>Load-terminal voltage and required equipment function during takeover<\/td>\n<\/tr>\n<tr>\n<td>Input return<\/td>\n<td>Startup demand, load continuity, charging behavior and any alarms<\/td>\n<\/tr>\n<tr>\n<td>Reserve restored<\/td>\n<td>Defined readiness endpoint, elapsed time and response to the next required event<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<p>Retain battery identity and condition, full supply suffix, wiring revision, settings and measurement points. Have the test owner state which limits passed and which remain open. This keeps a successful first backup event from being mistaken for verified repeat-event readiness.<\/p>\n<p>Put these requirements in the purchase annex rather than relying on a generic UPS description. Ask the supplier to identify the document revision and the operating states covered by its response. When a battery, harness or load changes, compare the affected current and recovery records before carrying forward the earlier acceptance.<\/p>\n<p><a href=\"https:\/\/www.wehopower.com\/bn\/product\/ups-120w-ac-to-dc-single-output-power-supply-for-battery-charge\/\">Review the WEHO SC-120 product details<\/a> with the specification. <a href=\"https:\/\/www.wehopower.com\/bn\/contact\/\">Send WEHO the separate load and recovery requirements<\/a>, including the battery proposal and required operating states, to request the matching model documents and remaining verification evidence.<\/p>\n<\/div>","protected":false},"excerpt":{"rendered":"<p>Review the SC-120-12 with separate equipment-load and charging budgets, then define what evidence proves the reserve is ready for another event.<\/p>","protected":false},"author":2,"featured_media":20466,"parent":0,"menu_order":3,"comment_status":"","ping_status":"","template":"","format":"standard","meta":{"_acf_changed":false,"_joinchat":[],"footnotes":""},"news_category":[284],"class_list":["post-20489","news","type-news","status-publish","format-standard","has-post-thumbnail","hentry","news_category-product-articles","entry"],"acf":[],"post_mailing_queue_ids":[],"_links":{"self":[{"href":"https:\/\/www.wehopower.com\/bn\/wp-json\/wp\/v2\/news\/20489","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.wehopower.com\/bn\/wp-json\/wp\/v2\/news"}],"about":[{"href":"https:\/\/www.wehopower.com\/bn\/wp-json\/wp\/v2\/types\/news"}],"author":[{"embeddable":true,"href":"https:\/\/www.wehopower.com\/bn\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.wehopower.com\/bn\/wp-json\/wp\/v2\/comments?post=20489"}],"version-history":[{"count":0,"href":"https:\/\/www.wehopower.com\/bn\/wp-json\/wp\/v2\/news\/20489\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.wehopower.com\/bn\/wp-json\/wp\/v2\/media\/20466"}],"wp:attachment":[{"href":"https:\/\/www.wehopower.com\/bn\/wp-json\/wp\/v2\/media?parent=20489"}],"wp:term":[{"taxonomy":"news_category","embeddable":true,"href":"https:\/\/www.wehopower.com\/bn\/wp-json\/wp\/v2\/news_category?post=20489"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}