Se servir du développeur Backpack

I don't have the exact number here (weekend off), but the 3.3V buck converter should be able to supply 600mA AFAIK, but that already includes the microcontroller, screen, backlight, micro SD card, LEDs... Well everything except sound. You can turn all the lights on with the home menu, and measure the current consumption to get an idea.

So, you should be able to power an ESP8266. Just try, the converter has overload protection. If it doesn't work, add an external 3.3V regulator powered directly by VBAT. Also make sure that it's shut down when there is no 3V3, or else you'll empty the battery even when it's off. 

No need to add external battery, the 900mAh is plenty already. You'll avoid lots of problem by using the included one.

Hope that helps :)

Ooo, good thinking - thank you! :)

I really think the included battery will be enough and avoid you lots of trouble though, and said just above ^^

Awesome - thank you - this is excellent detail! <3  Any chance I can get an answer to this as well - right now my Backpack project is stalled without it:

https://gamebuino.com/community/topic/using-spi-with-the-backpack?page=1

Thank you!!