{"id":17281,"date":"2026-08-14T18:02:03","date_gmt":"2026-08-14T18:02:03","guid":{"rendered":"https:\/\/www.yulidapower.com\/?p=17281"},"modified":"2026-08-27T02:04:01","modified_gmt":"2026-08-27T02:04:01","slug":"how-to-test-power-bank-quality","status":"publish","type":"post","link":"https:\/\/www.yulidapower.com\/fr\/how-to-test-power-bank-quality\/","title":{"rendered":"Comment tester la qualit\u00e9 d\u2019une batterie externe avant une commande en gros : liste de contr\u00f4le en 15 points pour les acheteurs"},"content":{"rendered":"<h1 class=\"wp-block-heading has-text-align-center\">Comment tester la qualit\u00e9 d\u2019une batterie externe avant une commande en gros : liste de contr\u00f4le en 15 points pour les acheteurs<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Short answer:<\/strong> Start with the approved sample and a written specification. Test production samples under the same conditions, then check whether the model, battery energy, usable output, charging profiles, protection functions, temperature, construction, labels and documents still match. Keep the meter logs, test conditions, sample size and pass\/fail limits with the inspection report.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Good finish tells you very little about the battery pack or PCBA inside. Capacity, charging speed, heat and batch consistency have to be measured. Buyer-side testing has a narrower job than formal certification testing: it checks whether the sample, specification, production lot and supporting documents describe the same product.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">What Should Buyers Test Before Ordering Power Banks in Bulk?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Use these 15 checks as the working outline for an OEM or wholesale inspection plan. Set the actual limits from the approved specification, the target market and the purchase agreement. A generic checklist cannot decide those numbers for you.<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table><thead><tr><th>No.<\/th><th>Quality checkpoint<\/th><th>What to verify<\/th><th>Evidence to keep<\/th><\/tr><\/thead><tbody><tr><td>1<\/td><td>Product identity<\/td><td>Model, housing, ports, battery configuration, firmware and accessories match the approved sample<\/td><td>Signed specification, sample photos and change log<\/td><\/tr><tr><td>2<\/td><td>Rated capacity and Wh<\/td><td>Labelled mAh, nominal voltage and watt-hour calculation are consistent<\/td><td>Label artwork and battery specification<\/td><\/tr><tr><td>3<\/td><td>Usable output energy<\/td><td>Measured energy under a defined load and cut-off condition<\/td><td>Discharge curve and test conditions<\/td><\/tr><tr><td>4<\/td><td>Conversion efficiency<\/td><td>Input energy from the battery versus usable output energy<\/td><td>Meter log and calculation method<\/td><\/tr><tr><td>5<\/td><td>Input charging<\/td><td>Input voltage, current, power and full-charge behaviour<\/td><td>Charging curve and charger\/cable details<\/td><\/tr><tr><td>6<\/td><td>Wired output<\/td><td>Each port delivers the agreed voltage, current and maximum power<\/td><td>Electronic-load results by port<\/td><\/tr><tr><td>7<\/td><td>Protocol support<\/td><td>Advertised PD, QC or other profiles negotiate with suitable devices or testers<\/td><td>Protocol-tester screenshots or logs<\/td><\/tr><tr><td>8<\/td><td>Simultaneous output<\/td><td>Total power allocation and behaviour when several ports are used<\/td><td>Multi-port load test<\/td><\/tr><tr><td>9<\/td><td>Protection functions<\/td><td>Over-current, short-circuit, overcharge, over-discharge and temperature protections as applicable<\/td><td>Pass\/fail record and recovery behaviour<\/td><\/tr><tr><td>10<\/td><td>Temperature<\/td><td>Surface and critical-point temperature during charging and discharging<\/td><td>Temperature log and ambient condition<\/td><\/tr><tr><td>11<\/td><td>Standby behaviour<\/td><td>Auto-shutoff, low-current mode and self-discharge where specified<\/td><td>Time-based functional record<\/td><\/tr><tr><td>12<\/td><td>Ports and cables<\/td><td>Connector fit, insertion, built-in cable strain and repeated use<\/td><td>Cycle count and visual record<\/td><\/tr><tr><td>13<\/td><td>Mechanical integrity<\/td><td>Housing gaps, buttons, assembly, drop or transport simulation required by the quality plan<\/td><td>Inspection and test report<\/td><\/tr><tr><td>14<\/td><td>Appearance and packaging<\/td><td>Colour, logo, print, labels, manuals, carton protection and barcode data<\/td><td>Golden sample and approved artwork<\/td><\/tr><tr><td>15<\/td><td>Batch traceability<\/td><td>Cell lot, PCBA revision, firmware, production date and inspection records can be traced<\/td><td>Lot code and shipment inspection file<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">1. Freeze the Specification Before Testing<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Testing goes nowhere when the buyer and supplier use different specifications. Before sample approval, put the finished model, battery cell or pack, PCBA revision, charging IC, port layout, rated input and output, protocols, firmware, housing, dimensions, weight, accessories, packaging and markings into one controlled document.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Mark the approved unit as the golden sample or pre-production sample. Photograph it and note the revision date. If the factory later proposes another cell, protection board, cable, wireless coil, magnet, firmware or enclosure, review the change in writing. The product may look identical while its performance or compliance scope has changed.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full\"><img fetchpriority=\"high\" decoding=\"async\" width=\"600\" height=\"400\" src=\"https:\/\/www.yulidapower.com\/wp-content\/uploads\/2026\/08\/power-bank-golden-sample-inspection-article.webp\" alt=\"Chinese quality inspector comparing a golden sample with production power banks\" class=\"wp-image-17291\" srcset=\"https:\/\/www.yulidapower.com\/wp-content\/uploads\/2026\/08\/power-bank-golden-sample-inspection-article.webp 600w, https:\/\/www.yulidapower.com\/wp-content\/uploads\/2026\/08\/power-bank-golden-sample-inspection-article-365x243.webp 365w\" sizes=\"(max-width: 600px) 100vw, 600px\" \/><\/figure>\n<\/div>\n\n\n<p class=\"wp-block-paragraph\">This document-control step complements a broader <a href=\"https:\/\/www.yulidapower.com\/fr\/verify-a-power-bank-manufacturer-in-china\/\">power bank factory audit<\/a>. A factory audit checks the supplier; a product test checks the item you are actually buying.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">2. Check Rated Capacity, Watt-Hours and Usable Energy<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The mAh figure printed on a power bank normally describes the internal battery at its nominal voltage. USB output runs at another voltage and passes through a conversion circuit. Comparing output mAh directly with the cell rating therefore gives a misleading result unless voltage and conversion loss are included.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Start with watt-hours. The basic relationship is <strong>Wh = V \u00d7 Ah<\/strong>. For example, 10,000mAh equals 10Ah; when the stated nominal voltage is 3.7V, the nominal battery energy is 37Wh. The <a href=\"https:\/\/www.iata.org\/contentassets\/05e6d8742b0047259bf3a700bc9d42b9\/lithium-battery-guidance-document.pdf\" rel=\"nofollow noopener\" target=\"_blank\">IATA lithium battery guidance<\/a> uses the same formula and treats power banks as batteries for transport purposes.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Measure usable output with a calibrated power meter or electronic load. Note the output voltage, load, starting state of charge, cut-off point, room temperature and cable. Report the result in Wh alongside those conditions. Without the method, another person cannot reproduce the number.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full\"><img decoding=\"async\" width=\"600\" height=\"400\" src=\"https:\/\/www.yulidapower.com\/wp-content\/uploads\/2026\/08\/power-bank-capacity-output-testing-article.webp\" alt=\"Power bank capacity and USB output testing with an electronic load\" class=\"wp-image-17292\" srcset=\"https:\/\/www.yulidapower.com\/wp-content\/uploads\/2026\/08\/power-bank-capacity-output-testing-article.webp 600w, https:\/\/www.yulidapower.com\/wp-content\/uploads\/2026\/08\/power-bank-capacity-output-testing-article-365x243.webp 365w\" sizes=\"(max-width: 600px) 100vw, 600px\" \/><\/figure>\n<\/div>\n\n\n<h2 class=\"wp-block-heading\">3. Measure Conversion Efficiency Correctly<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Conversion efficiency accounts for part of the gap between nominal battery energy and the energy that reaches a device. Calculate it from energy measurements taken under one defined condition. Dividing two unrelated mAh figures does not work. Output voltage, load, temperature, cable loss and the converter all affect the result.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Use the same output profile when comparing suppliers.<\/li>\n\n\n\n<li>State whether the result is measured at 5V, a PD profile or another mode.<\/li>\n\n\n\n<li>Keep the electronic-load or power-meter log.<\/li>\n\n\n\n<li>Agree on an acceptance limit in the specification before placing the order.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">A higher percentage means little when two suppliers used different methods. Retest both samples under the same conditions.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">4. Verify Input Charging and Full-Charge Behaviour<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Test the power bank with a known charger and cable that support the required input profile. Record input voltage, current, power, charging time and behaviour near full charge. Check whether charging remains stable, whether the indicator reaches the correct state and whether the unit becomes unexpectedly hot.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Charging time becomes useful only after you control the starting charge level, charger, cable, temperature and end condition. Test pass-through charging when it appears in the approved specification; otherwise leave it out of the acceptance decision.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">5. Test Every Output Port and Advertised Power Profile<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Test every wired output, not just the easiest USB port to reach. Apply a controlled load and check the agreed voltage, current and maximum wattage. For USB-C PD or another fast-charging claim, use a suitable protocol tester and a few representative devices. Save the negotiated profiles and identify the cable used.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u201cPD supported\u201d is incomplete information. The buyer needs to know which voltage-current profiles are available, which ports support them, whether input and output use the same port and what happens when more than one device is connected.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">6. Test Multi-Port and Built-In Cable Behaviour<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">One port may reach the advertised wattage while the total changes as soon as a second cable is connected. Test the combinations customers are likely to use. Note total power, the split between ports, any renegotiation and whether an existing connection briefly drops.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For a power bank with built-in cables, inspect cable length, connector direction, fit, strain relief and storage. Bend or pull tests should follow the agreed quality plan rather than an improvised force. Buyers developing this category can also use the <a href=\"https:\/\/www.yulidapower.com\/fr\/how-to-choose-a-power-bank-with-built-in-cable-for-oem-orders\/\">built-in cable power bank OEM guide<\/a> when defining the sample specification.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">7. Confirm Protection Functions Safely<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The approved plan may call for over-current, short-circuit, overcharge, over-discharge or over-temperature checks. These are not casual desk tests. They can destroy a sample or create a battery hazard, so trained personnel need suitable equipment, containment and written procedures.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Record both the trip condition and the recovery behaviour. A simple \u201cpass\u201d does not show when protection activated, whether output stopped correctly or how the unit returned to normal operation. Formal safety certification testing should be handled by a qualified laboratory where required; a buyer\u2019s functional check does not replace it.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">UL describes <a href=\"https:\/\/www.ul.com\/news\/setting-standard-ul-introduces-first-dedicated-safety-standard-ul-2056-power-bank-industry\" rel=\"nofollow noopener\" target=\"_blank\">UL 2056<\/a> as a power-bank-specific safety program that includes electrical, mechanical, capacity-marking and output-overload evaluations. The exact standard and certification route still depend on the product and market.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">8. Monitor Temperature During Real Operating Modes<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Temperature should be logged during input charging, normal discharge and the highest-power mode included in the specification. For wireless models, check aligned and reasonably misaligned positions when those conditions are part of the intended use. Record ambient temperature, measurement location and test duration.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">One surface-temperature limit cannot be applied responsibly to every power bank. Set the limit from the applicable safety requirements, component ratings, design risk assessment and product specification. Investigate unexplained heat, repeated shutdowns or unstable power before releasing the design.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">9. Check Standby, Auto-Shutoff and Self-Discharge<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">A short output test can miss standby-current and firmware problems. Check auto-start, auto-shutoff, indicator accuracy and idle power draw. If the product advertises a low-current mode for earbuds or wearables, test that mode with an appropriate load.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Self-discharge needs a defined time interval and storage condition. If the purchase specification includes a limit, store charged samples for the agreed period and measure the remaining energy using the same method. Avoid judging self-discharge from LED bars alone.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">10. Inspect Ports, Buttons, Housing and Mechanical Assembly<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Electrical performance is only part of product quality. Check connector alignment and retention, button feel, display readability, housing gaps, sharp edges, loose parts and unusual sounds. Compare weight and dimensions with the approved tolerance because unexplained differences can reveal material or component changes.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Drop, vibration, compression or cable-cycle checks should follow a documented method with defined sample conditioning and acceptance rules. After testing, inspect the enclosure and repeat relevant electrical and protection checks. A unit that still turns on may nevertheless have internal damage.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">11. Approve Appearance, Labels and Packaging Against Artwork<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Use signed artwork and a colour reference rather than approving appearance from chat photos. Inspect logo position, print sharpness, colour consistency, surface finish, seams, labels, user manual, barcode, carton markings and accessories. Confirm that electrical ratings and battery Wh are legible and consistent across the product, packaging and documentation.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Packaging should protect the selected model through the planned distribution route. Review tray fit, cable placement, retail-box closure and master-carton configuration. If a retailer has packaging rules, add them to the inspection checklist before production starts.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">12. Match Compliance Documents to the Exact Product<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">A logo on the box does not prove that a report covers the ordered product. Match the manufacturer, model number, ratings, battery or cell, report date, laboratory and standard to the approved configuration. Our <a href=\"https:\/\/www.yulidapower.com\/fr\/power-bank-certifications-compliance\/\">guide des certifications et de la conformit\u00e9 des batteries externes<\/a> separates the roles of CE, FCC, RoHS, UN 38.3, IEC 62133-2, China CCC and Qi or Qi2.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><a href=\"https:\/\/webstore.iec.ch\/en\/publication\/65948\" rel=\"nofollow noopener\" target=\"_blank\">IEC 62133-2<\/a> addresses safety requirements for portable sealed secondary lithium cells and batteries. Transport evidence, product safety, EMC, restricted substances and wireless interoperability are separate questions; one report should not be assumed to cover all of them.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">13. Use a Pre-Shipment Sampling Plan<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">One development sample says nothing about the consistency of a finished lot. Before shipment, define the lot and random-sampling method. Put the sample size, defect categories, acceptance limits, inspection timing and responsibility for reinspection into the purchase agreement.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full\"><img decoding=\"async\" width=\"600\" height=\"400\" src=\"https:\/\/www.yulidapower.com\/wp-content\/uploads\/2026\/08\/power-bank-pre-shipment-quality-inspection-article.webp\" alt=\"Pre-shipment quality inspection of packaged power banks in a Chinese factory\" class=\"wp-image-17293\" srcset=\"https:\/\/www.yulidapower.com\/wp-content\/uploads\/2026\/08\/power-bank-pre-shipment-quality-inspection-article.webp 600w, https:\/\/www.yulidapower.com\/wp-content\/uploads\/2026\/08\/power-bank-pre-shipment-quality-inspection-article-365x243.webp 365w\" sizes=\"(max-width: 600px) 100vw, 600px\" \/><\/figure>\n<\/div>\n\n\n<p class=\"wp-block-paragraph\">If the contract uses an AQL plan, write the inspection level and defect limits into the purchase order. Do not use \u201cstandard AQL\u201d as a substitute for actual numbers. Safety-critical defects may require a different rule from cosmetic defects, and some checks may be performed on 100% of units while others are sampled.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">14. Keep Traceable Test Records<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">A good inspection report lets another person identify the sample and repeat the test. Keep the following details:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Purchase order, model, lot and sample serial or traceability code<\/li>\n\n\n\n<li>Approved specification and golden-sample revision<\/li>\n\n\n\n<li>Battery-cell lot, PCBA or firmware revision when available<\/li>\n\n\n\n<li>Test equipment identification and calibration status<\/li>\n\n\n\n<li>Ambient conditions, load, charger, cable and test duration<\/li>\n\n\n\n<li>Expected limit, measured result and pass\/fail decision<\/li>\n\n\n\n<li>Photos, meter screenshots and discharge or charging curves<\/li>\n\n\n\n<li>Inspector, test date, corrective action and reinspection result<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Consistent records matter more than a polished certificate with no model traceability. They also make later failure analysis and repeat-order comparisons much faster.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">15. Define What Happens When a Sample Fails<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Decide what a failed result means before production starts. The purchase agreement can require sorting, rework, replacement, root-cause analysis or a new inspection. It should also block component substitutions that the buyer has not approved.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Ask for evidence that the cause\u2014not only the failed unit\u2014was addressed. A reasonable corrective-action file identifies the defect, affected lot, containment action, root cause, permanent correction and verification result. For a design or component change, review whether previous compliance documents remain applicable.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">A Practical Three-Stage Approval Process<\/h2>\n\n\n\n<figure class=\"wp-block-table\"><table><thead><tr><th>\u00c9tape<\/th><th>Objectif<\/th><th>Buyer decision<\/th><\/tr><\/thead><tbody><tr><td>Development sample<\/td><td>Compare functions, construction and user experience with the sourcing requirement<\/td><td>Select or reject the model<\/td><\/tr><tr><td>Pre-production sample<\/td><td>Freeze materials, firmware, artwork, packaging and measurable limits<\/td><td>Authorize mass production<\/td><\/tr><tr><td>Pre-shipment inspection<\/td><td>Check random production samples and required records against the approved reference<\/td><td>Release, rework, reinspect or hold shipment<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">This three-stage process deals with a familiar sourcing problem: the approved sample looks right, but the shipment uses a different component set. For a custom project, tie the test plan to the change-control and approval clauses in the <a href=\"https:\/\/www.yulidapower.com\/fr\/oem-odm\/\">OEM\/ODM manufacturing agreement<\/a>.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Questions to Send a Supplier Before You Order Samples<\/h2>\n\n\n\n<ol class=\"wp-block-list\">\n<li>Which exact battery cell or pack and PCBA revision are used in this model?<\/li>\n\n\n\n<li>What are the rated battery Wh and supported input\/output profiles?<\/li>\n\n\n\n<li>Can you provide a model-specific specification and current test reports?<\/li>\n\n\n\n<li>How do you measure usable capacity and conversion efficiency?<\/li>\n\n\n\n<li>Which checks are performed on every unit and which are sampled?<\/li>\n\n\n\n<li>How are cell lots, firmware and finished goods traced?<\/li>\n\n\n\n<li>What substitutions require buyer approval?<\/li>\n\n\n\n<li>Can a third-party inspector access the goods before shipment?<\/li>\n\n\n\n<li>What happens if the lot fails the agreed inspection?<\/li>\n\n\n\n<li>Which records will accompany the shipment?<\/li>\n<\/ol>\n\n\n\n<h2 class=\"wp-block-heading\">How YULIDA Supports Buyer Verification<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">YULIDA publishes a quality-control workflow for electrical function, charging performance and appearance. Test items and records vary by model and order specification. Ask for the files that match the quoted configuration; a report for another model may not apply.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Review the <a href=\"https:\/\/www.yulidapower.com\/fr\/controle-qualite\/\">YULIDA processus de contr\u00f4le qualit\u00e9<\/a>, compare available models and then <a href=\"https:\/\/www.yulidapower.com\/fr\/contactez-nous\/\">request a model-specific sample and inspection checklist<\/a>. Include your target market, required capacity, ports, power profiles, quantity, branding needs and planned shipment method so the factory can prepare the correct specification and document set.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">What to Approve Before Shipment<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Before shipment, the approved sample, specification, meter logs, production lot and compliance documents should all point to the same configuration. Check the 15 items under written conditions and keep the results with the order file. If the lot differs from the sample or misses an agreed limit, hold it for investigation or reinspection.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Questions fr\u00e9quentes<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">1. What power bank test documents should a buyer request before a bulk order?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Ask for the approved product specification, model-specific test records, battery and protection-board information, relevant compliance documents, packaging artwork and a pre-shipment inspection plan. Check that every document refers to the same model and configuration you intend to buy.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">2. How should usable power bank capacity be tested?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Measure usable output with a calibrated power meter or electronic load and report the result in watt-hours. Record the output voltage, load, cable, room temperature, starting charge level and cut-off point so another inspector can repeat the test under the same conditions.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">3. Is one approved sample enough for a bulk order?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">No. An approved sample establishes the target, but it does not prove that the finished production lot is consistent. Buyers should also inspect randomly selected units from the completed lot before shipment.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">4. Why should a buyer keep a golden sample?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">A signed or clearly identified golden sample gives the buyer, supplier and inspector the same physical reference for appearance, materials, ports, labels, packaging and expected performance. Any proposed component or firmware change should be reviewed against it in writing.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">5. How many power banks should be checked before shipment?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The sample size should be agreed before production and should reflect the lot size, product risk and defect categories. Put the sampling method, acceptance limits and reinspection responsibility in the purchase agreement instead of deciding them after a problem appears.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">6. Can a certificate for one power bank model cover another model?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Not automatically. Model name, cell, protection board, ports, enclosure, wireless-charging assembly and other construction details can affect the applicable report scope. Ask the supplier or laboratory to confirm that the documents cover the exact configuration being ordered.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Sources officielles de r\u00e9f\u00e9rence<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><a href=\"https:\/\/webstore.iec.ch\/en\/publication\/65948\" rel=\"nofollow noopener\" target=\"_blank\">IEC 62133-2: Safety requirements for portable lithium cells and batteries<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/www.iata.org\/contentassets\/05e6d8742b0047259bf3a700bc9d42b9\/lithium-battery-guidance-document.pdf\" rel=\"nofollow noopener\" target=\"_blank\">IATA Lithium Battery Guidance Document<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/www.ul.com\/news\/setting-standard-ul-introduces-first-dedicated-safety-standard-ul-2056-power-bank-industry\" rel=\"nofollow noopener\" target=\"_blank\">UL Solutions: UL 2056 for power banks<\/a><\/li>\n<\/ul>","protected":false},"excerpt":{"rendered":"<p>Apprenez \u00e0 tester la qualit\u00e9 des batteries externes avant une commande en gros avec une liste de contr\u00f4le en 15 points : capacit\u00e9, puissance de sortie, protocoles, s\u00e9curit\u00e9, temp\u00e9rature, durabilit\u00e9, documents et \u00e9chantillonnage avant exp\u00e9dition.<\/p>","protected":false},"author":1,"featured_media":17284,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"om_disable_all_campaigns":false,"footnotes":""},"categories":[101],"tags":[],"class_list":["post-17281","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-news"],"_links":{"self":[{"href":"https:\/\/www.yulidapower.com\/fr\/wp-json\/wp\/v2\/posts\/17281","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.yulidapower.com\/fr\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.yulidapower.com\/fr\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.yulidapower.com\/fr\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.yulidapower.com\/fr\/wp-json\/wp\/v2\/comments?post=17281"}],"version-history":[{"count":11,"href":"https:\/\/www.yulidapower.com\/fr\/wp-json\/wp\/v2\/posts\/17281\/revisions"}],"predecessor-version":[{"id":17683,"href":"https:\/\/www.yulidapower.com\/fr\/wp-json\/wp\/v2\/posts\/17281\/revisions\/17683"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.yulidapower.com\/fr\/wp-json\/wp\/v2\/media\/17284"}],"wp:attachment":[{"href":"https:\/\/www.yulidapower.com\/fr\/wp-json\/wp\/v2\/media?parent=17281"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.yulidapower.com\/fr\/wp-json\/wp\/v2\/categories?post=17281"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.yulidapower.com\/fr\/wp-json\/wp\/v2\/tags?post=17281"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}