Sourcing Power Banks from China: Wholesale Guide

Power banks are one of the most popular sourcing categories from China, and also one with the highest rate of spec fraud. Capacity inflation is rampant — a product labeled “20,000mAh” might actually contain 6,000–8,000mAh of usable capacity. This happens at the factory level, and many importers don’t find out until their first batch of customer returns.

This guide tells you how to evaluate suppliers, which specs matter and how to verify them, and the lithium battery shipping regulations you must understand before you place an order.

Factory Tiers and What They Cost

Budget ($2.50–6 factory cost): Slim credit-card style or small cylindrical power banks. 5,000–10,000mAh claimed. Often use no-name lithium cells that degrade fast and can’t sustain the rated discharge current. Budget for promotional giveaways, low-demand markets. Not suitable for brands selling in the US or EU where returns damage your metrics.

Mid-range ($6–18 factory cost): Standard brick-style power banks. 10,000–20,000mAh capacity range (credible if from a quality factory). Multiple ports. USB-C PD charging support. Some GaN charger-integrated designs in this tier. Factories in Shenzhen (Bao’an district) dominate this segment and export heavily to the US.

Premium ($18–40 factory cost): 20,000–30,000mAh, magnetic charging (MagSafe compatible), 65W–140W PD fast charging, GaN technology reducing size for given output, simultaneous charge-through (charge the bank while charging your device). Some factories at this tier supply to Anker, Belkin, and similar brands.

The Capacity Fraud Problem

This is the defining quality issue in this category. Here’s how it works:

Lithium cells have a rated capacity in mAh. Power banks have a “total cell capacity” (the sum of all internal cells) and a “usable output capacity” (what you actually get out, after conversion losses of typically 10–15%). Legitimate brands specify output capacity, not cell capacity.

Fraudulent or cheap suppliers:

• Label with cell capacity, not output capacity
• Use cells rated at 3.7V but calculate mAh at a different voltage to inflate the number
• Use cells that have the nominal capacity when new but degrade to 50% after 30 charge cycles
• Simply lie. 6,000mAh of cells in a box labeled 20,000mAh.

How to verify capacity before placing an order: Get samples. Charge completely. Then discharge into a known load (a USB load tester like a YK-001 USB meter costs under $20) while recording mAh output. Compare to claimed capacity. A legitimate 10,000mAh power bank should output 8,000–9,000mAh to a USB device (accounting for conversion losses). If it outputs 4,000mAh, the capacity is fake.

Run this test on every sample from every new supplier. No exceptions.

Specs That Drive Purchase Decisions

Charging protocols. USB Power Delivery (PD) is the dominant standard and required to fast-charge modern smartphones and charge laptops. Qualcomm Quick Charge (QC) 3.0/4.0 is also common. Check which protocols the power bank supports as input (charging the bank) and output (charging your devices). Budget power banks often have only standard 5V/2.4A output — fine for older phones, useless for fast-charging anything modern.

Output power. A 65W PD output can charge a MacBook Air. A 100W output can charge most laptops. A single 18W output only fast-charges phones. For business-focused buyers, higher output wattage is a strong selling point.

Number and type of ports. Buyers want at least one USB-C PD port, one USB-A, and ideally two charging outputs simultaneously. Check whether total output power drops when multiple ports are in use (common with cheap designs — a “65W” bank might only do 18W per port when both are in use).

Size and weight for the capacity. GaN technology allows smaller chargers for the same wattage. A traditional 10,000mAh power bank weighs 200–250g. A well-engineered GaN version might weigh 150g. Weight matters for travel buyers.

Pass-through charging. Can the power bank charge your device while simultaneously being charged from the wall? Cheap designs heat up badly doing this. Test it.

Cell brand. Ask explicitly what cells are inside. Samsung SDI, LG Chem, Panasonic/Sanyo, Murata, and CATL are reputable manufacturers. Unnamed cells (often from lower-tier Chinese suppliers) vary wildly. Some are fine; many degrade fast or fail safety standards. Premium-tier importers specify cell brand in the purchase order.

Lithium Battery Shipping Rules

This is not optional knowledge. Power banks contain lithium-ion batteries, which are classified as dangerous goods for air transport.

IATA regulations (air freight and express services like DHL/FedEx/UPS):

• Power banks ≤100Wh can ship in carry-on or air freight with proper packaging and declaration
• Power banks 100–160Wh can ship as cargo with airline approval (not easily)
• Power banks >160Wh are banned from air shipment entirely

To calculate Wh: multiply voltage (3.7V nominal) × capacity in Ah. A 20,000mAh battery = 20Ah × 3.7V = 74Wh. Safely under the 100Wh limit for standard air freight.

UN38.3 certification: Required for any lithium battery product being shipped internationally. It’s a series of tests (shock, vibration, altitude simulation, thermal, overcharge, etc.) that certify the cells are safe for transport. Any factory selling into the US or EU should have UN38.3 test reports for their cells. Ask for this before ordering.

Labeling: Shipments containing lithium batteries require specific DG labels and markings on the outer carton. Your freight forwarder will handle this if you tell them the product contains lithium batteries — and you should always tell them.

See our lithium battery shipping guide for the full logistics picture.

Certifications Needed

UL 2056 is the US standard specifically for power banks. Many large retailers require it. Getting a new product UL certified runs $3,000–8,000 and takes 2–3 months. Many Chinese factories already have UL-listed power banks on their lineup — verify the file number at ul.com.

FCC Part 15B applies to any power bank with USB PD controllers that emit RF (though most power banks don’t have active wireless, any digital electronics sold in the US technically needs compliance documentation). Check with your factory.

CE + LVD + EMC for EU/UK market.

PSE (Japan) if you’re selling there.

For US Amazon sales, FCC documentation and either UL listing or equivalent safety documentation is increasingly required. Check Amazon’s current policy for your category.

MOQs

Stock designs (existing model, your label on the packaging): 100–500 units. Good factories will quote 200 as a floor for standard designs.

Custom branding (logo on unit, custom box): 500–1,000 units.

Custom capacity/form factor: 2,000+ units with tooling. It’s rarely worth customizing the form factor at low volumes — find a factory whose catalog design meets your needs.

Spotting Good vs. Bad Factories

A good power bank factory will:

• Have UN38.3 test reports they can share
• Be able to tell you exactly which cell supplier they use
• Provide actual output mAh test data for their products (not just claimed capacity)
• Have exported to US or EU markets and understand CE/UL requirements
• Be willing to sign a product spec sheet before production

A bad one will:

• Give vague answers about cell sourcing (“we use high quality domestic cells”)
• Claim capacity numbers that don’t match cell volume (a slim 10mm thick power bank cannot physically fit the cells for a genuine 20,000mAh)
• Only offer PayPal or Western Union
• Have a product catalog that includes power banks, drones, and office furniture

Frequently Asked Questions

How do I test power bank capacity honestly? Fully charge the bank. Connect a USB load tester (YK-001 or similar) or use a known-draw device while measuring output with a USB multimeter. Record total mAh delivered to cutoff. A legitimate 10,000mAh bank should output 8,000–9,000mAh. Less than 70% of claimed capacity = the spec is false.

What is UN38.3 certification and do I need it? UN38.3 is a series of transport safety tests for lithium batteries mandated by IATA for air shipments. Any power bank shipped by air must have UN38.3 certified cells. Reputable factories already have this. If a factory can’t provide UN38.3 test reports, their cells aren’t certified for air transport and you’ll have problems getting freight booked.

Can I ship power banks by sea to avoid lithium battery air restrictions? Yes. Sea freight is not subject to IATA lithium battery regulations (though IMDG code rules still apply and require proper declaration and packaging). Sea freight is the standard mode for bulk power bank imports.

What is the airline carry-on limit for power banks? The standard limit is 100Wh per bank. A 20,000mAh bank at 3.7V = 74Wh, which is under the limit. A 27,000mAh bank at 3.7V = 99.9Wh, just under. Banks over 100Wh need airline approval. Banks over 160Wh are banned from passenger aircraft entirely. Wh should be printed on the bank — verify it matches the actual capacity.

Do I need UL certification to sell power banks on Amazon? Amazon’s requirements change. As of early 2026, Amazon increasingly requires UL 2056 or equivalent accredited lab testing for power banks sold on their platform. Check the current Amazon Seller Central requirements for your category before ordering inventory without certification.