Determining the Duration a 22000 mAh USB Power Bank Can Power a 5V-3W Device

To determine how long a 22000 mAh rated USB power bank can power a device that requires 5V and 3W, we need to calculate the capacity of the power bank, the current draw of the device, and the runtime. We'll start by calculating the current draw of the device.

Calculate the Current Draw of the Device

The current draw (I) of a device can be determined using the formula for power (P), where P Voltage (V) × Current (I). Rearranging this formula gives us:

I frac{P}{V}

For a 3W device operating at 5V:

I frac{3W}{5V} 0.6A 600 mA

Calculate the Total Capacity of the Power Bank in mAh

The power bank is rated at 22000 mAh, which is the total capacity of the power bank.

Calculate the Runtime

The runtime can be calculated by dividing the capacity of the power bank in mAh by the current draw in mA. The formula is as follows:

Runtime frac{Capacity (mAh)}{Current (mA)}

Plugging in the values:

Runtime frac{22000 mAh}{600 mA} approx 36.67 hours

Therefore, under ideal conditions, a 22000 mAh USB power bank can power a device that requires 5V and 3W for approximately 36.67 hours. However, in real-world scenarios, efficiency factors can affect this runtime.

Real-World Considerations

Efficiency losses in power banks and during the conversion from a higher battery voltage to the USB output can significantly reduce the actual runtime. Assuming an average efficiency of around 80%, a more realistic estimate would be around 25-30 hours.

Breakdown of Efficiency Considerations

Therefore, if we consider these factors, 27 hours at 100% efficiency would translate into:

100% Efficiency 27 hours

80% Efficiency 27 times 0.8 times 0.8 17.4 hours

If the power bank's design and battery quality are of reasonable quality, the runtime would be around 17 hours.

Conclusion

To summarize, a 22000 mAh USB power bank can power a 5V 3W device for approximately 36.67 hours under ideal conditions, but in real-world scenarios, the actual runtime would be around 25-30 hours, considering various efficiency factors. For more detailed insights, please refer to my Quora Profile for additional calculations and real-world scenarios.