I want to use also a battery, as you said with 3.7V, HDMI, USB, mezzanine would not work.
The PMIC 8916 on the dragon board has Switched-mode power supplies, four buck converters, and one 5V boost converter.
On the datasheet of the PMIC 8916 page 50, Table 3-21 Boost specifications, they share that the boost output is 5V for 3.7V input.
I didn’t find any information where I can pick up this 5V boost output, or is it not connected to anything on the dragon board?
One other question would be, smartphones which are using the 410c, do they not have 3.7V batteries?