Microbit power bank
Powering microbits outdoors isn't easy: dry cells have quite a low capacity. Typically a microbit battery of 2 AAA cells can provide around 500 mAh, which might power a weather station for a couple of days. Another solution is a power bank. These are rechargeable batteries that are aimed at the mobile phone market - to keep your phone battery topped up. They are charged from a mains charger via a USB input port, and deliver 5V from a second port. The one I'm using is an Apachie 5200 mAh , which is available for around £8. It's the size of a typical phone. Power banks are intended to give your phone 's battery a boost - not to power some electronics which need a continuous supply! So they come with a means of testing if the load has been disconnected; the power bank can then switch off its internal circuits to reduce power wastage. This power bank does that by switching off for a short time (about 500 ms), every 5 seconds or so. That will cause the microbit supply to c