We discussed the lifespan of cell phone batteries in a previous article. Since portable chargers are built using basically the same technology, you can expect them to behave in a similar fashion to cell phone batteries. But let’s dive into the details of power banks in particular.
Similar to laptop and smartphone batteries, power banks also have a certain number of charge-discharge cycles before the device loses its capacity. Generally, lithium-ion batteries will be at 80% capacity after 500 cycles, while others will experience the same performance loss after 800-900 cycles. Afterward, the portable charger can last for a long time, but there will be a gradual loss in capacity.
A cycle is used up when the power in a portable charger goes from 100 to 0% and gets charged back to 100%. However, there are a few different ways to consume a cycle, which can be done by charging the device from 0 to 50% twice, 0 to 33% three times, and 0 to 25% four times. How frequently you charge and use a power bank will determine how quickly a cycle is consumed. A power bank will suffer from performance loss every time a cycle gets used up.
On average, power banks last 4 to 5 years and can hold a charge for 4-6 months without losing much power. For example, a 5000mAh portable charger that’s powered up once every two days, it will need 1,000 days to reach the 500 charge-discharge cycles and drop to 80% capacity.
Power banks that have a small battery capacity or low-quality build won’t last very long. This is mainly because the charge-discharge cycles will be consumed rather quickly. High-quality power banks with a large battery capacity will last a lot longer. Since the battery is bigger, you won’t need to charge it as often, which also means the cycles won’t be used up as quickly.
Regarding the amount of time a power bank can hold a charge, the majority of Li-ion and Li-poly power banks discharge themselves by 2% every month. The rate will often increase to 3% and 5%, depending on the type and care they receive. Storing the power bank in a hot area will also result in the device generating less power over time.
In the end, you should know that not all power banks are built the same. Some producers use higher quality materials, while others are using the cheapest possible parts. The build quality can have a major impact on overall battery life. Most power banks have 1-3 years of warranty upon purchase. So you get a minimum period of guaranteed high-performance out of our device. For example, this DB Power portable charger has a 3-year warranty.