[jaustin]

No battery charger on board, but we’ve done a lot of work on power management so you can sleep with very low power consumption (>100uA) on USB - which means you can use USB battery packs. AAAs work really nicely in classrooms and for teachers (easy to buy, clear what you need, low cost batteries are safe, also familiar for the existing 5M users), and have a lot going for them in terms of safety for open electric devices used by novices! The AAA batteries can also last a lot longer now if you design your code to be lower power.

You might also like some of the accessories people have made - I used these when strapping some micro:bits and RGB LEDs to samba drums and it worked great! http://www.kaise.com.tw/index.php?route=product/product&path...

[GekkePrutser]

Most USB battery packs will go to sleep themselves though when you use that little current, and turn off their output. But some have a "low power" option that can be activated to keep them on.