I agree about the arduino and batteries, but this board is a bit different.
It uses external memory which takes more power. It uses javascript which could take much more power. And the wifi also might not be low power. So it's not clear yet how low power it is.
It uses external memory which takes more power. It uses javascript which could take much more power. And the wifi also might not be low power. So it's not clear yet how low power it is.