FAQ About Power Banks（2）

Transportation of power banks in international trading

Power bank is a very popular product as rise of consumer electronics products, are widely demanded in all over the world. Due to the characteristics of lithium batteries, The power bank normally is classified into Class 9 DG cargo according to IATA regulation and IOM regulation who have very strict requirement in Sea, Air and road transportation.

The SOC< 30% is strictly required in air shipment as now become factory default, which is normally in 20-25% of the total capacity. Even the Sea shipment also will remain < 50% to be ensured the safety during transportation, which is normally in 40-50%.

The timeline from the moment of power banks is shipped from factory to buyer, and then to end user takes very long. However, its’ self-discharge already starts from the moment it is off from the production line, which have to be concerned and take consideration about its remaining power inside during transportation and local storage time. And take action to prevent the power bank over-discharge cause lowing its battery life or even totally failure.

What factors affect the self-discharge of polymer lithium batteries

1. Temperature: High temperature environments will accelerate the rate of self-discharge.
2. Storage time: The longer the storage time, the faster the self-discharge speed.
3. Storage environment: Excessive humidity or the presence of acidic gases in the air can accelerate the self-discharge rate.

In summary, although the self-discharge rate of polymer lithium batteries is relatively low, it is still necessary to pay attention to the storage environment to avoid accelerating the self-discharge rate and affecting the battery life.

How to reduce self-discharge phenomenon?

1. Storage of batteries: When storing lithium polymer batteries, attention should be paid to the storage environment. Do not let the battery overheat or become too cold. Generally, it needs to be stored in a dry and cool place.
2. Regular charging: Regular charging can reduce the rate of battery self-discharge. It is recommended to charge the battery every 3-6 months to maintain its healthy condition.

Suitable operating and storage temperatures for lithium polymer batteries

The storage temperature of batteries is generally 25 ± 5℃ at room temperature, which can affect the activity of lithium ions. The higher the temperature, the higher the activity. However, if the temperature exceeds 60℃, it may cause irreversible damage to the isolation film inside the battery, leading to battery scrapping. If the temperature is too low, the lithium-ion activity will be too low, resulting in the battery capacity not being discharged, which means it will run out of power.

Maintenance of power banks

1. Waterproof and moisture-proof:

As an electronic product, accidental water ingress or prolonged exposure to humid air can cause varying degrees of corrosion or oxidation to its internal electronic components, short circuit of battery as well.

2. Anti drop and shock:

The internal components of the power bank cannot withstand impact, so it is necessary to prevent accidental landing during use. Do not throw, strike, or vibrate the mobile power supply. Rough handling of mobile power sources can damage internal circuit boards and internal short circuit of battery.

3. Cold and heat protection:

High temperatures can shorten the lifespan of electronic devices and cause some plastic components to deform or melt. Working in a cold environment can cause moisture damage to the circuit board within a mobile power supply.

4. Correct charging and discharging:

It is best to discharge and charge once a month to ensure that the internal battery cells remain in optimal condition and effectively extend their service life. Avoid over charging or over discharging. When the battery level is too low, it should be charged in a timely manner; When the battery level is too high, charging or use should be stopped. Long time charging may cause the power bank overheat, and may even damage the power bank or cause safety hazards.

5. Storage:

Power banks should be stored in a moderately warm and dry place to prevent exposure to sunlight. The power bank must not be stored in a non-charged state for a long time to prevent damage to the battery due to over self-discharging. The power bank must be recharged at least once for every 3-6months. It is best to maintain the battery level between 60% and 70% before not using it. Please do not transport or store with metal items such as necklaces, hair clips, etc.

6. Safety usage:

Do not use the power bank too frequently, and do not charge too frequently. If used too frequently, it will shorten the service life of the power bank and increase the risk of danger. Stop using the power bank if it occurs expansion, swell or break down, May cause on fire.

Alarm or remind for charging of power bank

Due to the lithium battery special character, especially for air shipment, the IATA regulation requirements of SOC cause remaining battery power from Ex-factory is already very low. 2-5% self-discharge rate will consume its remaining power quickly, can’t last for a long-term storage.

A good charging and discharging maintenance can extend the power bank shelf time for many years.  

So, it is necessary to establish an alarm or reminding system to help reminding to charge the power bank regularly in warehouse before dispatched or sold.

Contact UUTEK for a “Storage Remind Table” to maintain your power bank stock in a proper and easy process.