Mobile power supply, also known as portable USB charger or portable spare battery power supply, is the external mobile power supply equipment of low voltage electronic products.The requirements of UL2056 cover mobile power terminal products and the standard is applicable to products with the highest DC power input and output rate of 60Vdc.

UL2056 mainly applies to mobile power terminal products:

Electrical test related to overcharge, short circuit, etc.;

Mechanical tests for the process of use, such as drop and extrusion;

Detection of labeled input/output current and power capacity;

Output port power overload testing.

Solution to UL2056:

1. Whether UL2056 is a global standard or not UL2056 is the world's first standard for mobile power, and no other country has similar requirements at present.Currently, it has not been recognized by other institutions, and it is the UL standard at the present stage. In the future, UL will discuss with the us government to gradually develop it into the us national standard and industry standard.

2. Specific requirements for certification application

Specific requirements to be adopted include:

A. Failure of A single part will not cause the risk of explosion or fire (UL 2056 focuses on this and helps enterprises to provide consumers with confidence and assurance of product safety)

B. materials must be fireproof

C. Product labeling, use instructions, etc. (mobile power products are directly used by consumers, so product labeling must be clear)

D. in addition to avoiding accidents involving lithium batteries, we have some tests to confirm this

3.UL2056 benefits mobile power manufacturers

After entering the 21st century, consumers' perceptions are constantly changing, and price is not the only factor to consider. Certain brand recognition is needed to ensure confidence in the use of safety.With UL 2056, manufacturers can prove that their mobile power products have passed UL's stringent test requirements to ensure that consumers are comfortable using.Products with a trusted UL logo, representing their product sample after a series of in-depth evaluations by UL professional engineers, can give consumers confidence.In addition, for products exported abroad, international competitiveness and reputation need to be improved, so as to occupy a better market position while gaining market access.UL labels for "made in China" will be a key basis for them to gain trust in the north American market as well as consumers around the world.

4.UL2056 test project vulnerability to failure and response measures

A. Overfilling test test

The easy failure index keeps going

Overcharge test is to test the battery in mobile power supply, the failure rate is relatively high, and the charging dc-dc (direct current flow) loop should be bypassed in the test.After the dc-dc loop is bypassed, the protection components in the charging protection loop will be replaced by a single component fault.

Countermeasures: at the beginning of the design of mobile power source, it should be considered that when the dc-dc loop is bypassed and the protection components in the charging protection loop are malfunctioned by a single component, it should still be able to withstand the overfilling test.Therefore, if necessary, the mobile power supply should be added another layer of protection.

B. Limited power test test

The vulnerability index keeps getting better

In the test, the output power of the output port cannot be greater than 8A or 100W in case of single component fault of the protection circuit.

What to do: add more protection if necessary.

C. temperature rise test

The error-prone index drops

The test is to test whether the temperature rise generated by the mobile power supply will exceed the temperature limit of the material used when the maximum charge-discharge voltage current is defined to work.Since there is a dc-dc loop in the mobile power supply, many heating components will be used, and the temperature will be easily raised during use.

Countermeasures: take the heating situation of components into full consideration when making printed circuit board layout design.

D. Capacity verification test

The prone to failure index is derived from one another

In the UL2056 test, this is the easiest test to fail.The test method is to discharge at the discharge port of the mobile power supply at the rated discharge current, discharge to the calibrated cut-off voltage, and the resulting capacity shall not be less than the rated capacity marked on the mobile power supply.In the actual test process, customers often meet the mark is not the mobile power capacity, but the cell capacity.As mentioned above, the actual output capacity of the battery is smaller than the core capacity due to the voltage conversion efficiency.

Response: application for UL certification of mobile power capacity identification should be the actual output capacity.If you want to mark the capacitance of the cell at the same time, you need to mark it clearly on the premise of mobile power capacity identification.