You're a Life Saver
Power banks are great for charging your phone on-the-go. They’re also great to use them to power your design projects. They offer a high energy density, are low profile, and rechargeable. Too bad you can’t use them for drones due to their low discharge rate.
Last updated March 2019
Power banks have become a necessity in our everyday lives. We use them to keep our mobile devices charged while we’re on-the-go. They come in all shapes, sizes, and charging capacities. They are lightweight and have their own charging circuitry built right in, which makes them ideal for your projects. Most development boards, sensors, and actuators you use in your project can be powered from the 5V output of the power bank or you can easily add a voltage regulator to drop the voltage from 5V to 3.3V.
It’s very common to see power banks with over 10,000 mAh capacity. For example, if your design draws 1A, you will be able to power it for 10 hours. If you can get your design to draw under 100mA, you’d be able to power it for 100 hours! The battery in the image is 13,000 mAh so you’d be able to power it for even longer.
There are some disadvantages to using lithium-ion power banks in your designs. If they are exposed to heat for a long period of time, they will degrade substantially. Make sure you keep your projects well ventilated if you have it outside. Another disadvantage is that if you discharge the battery completely, you won’t be able to recharge it again. The technology to counter this has gotten better as there is circuitry that monitors the charge. If it gets below, say, a 20% charge, the circuit will stop the flow of current.
Another thing to consider is the relatively low discharge rate of the power bank. You can’t use them to power those hungry DC motors on a drone. They require a substantial amount of current to provide the thrust required to lift your drone. What type of battery do you have to use? Lithium-polymer. They are a bit more expensive but they pack the necessary punch.
What did we learn?
Power banks can be used to power most designs and are convenient due to their internal charging circuit.
Choosing the correct battery type depends on how much current you need to provide to your load.