Hi Marion,

I would like to use a module Overo Airstorm(+Tobi) with Lithium Ion batteries (3.7V).

I saw in datasheet that Tobi supply might be included between 3.5 and 5V.

I also need to use USB in this module (5V,500mA).

Does anyone already try to supply the system with batteries and voltage below 5V? What was the result?

The input voltage is directly powering the USB power switch (for the host connector, OTG is
provided by the Overo/twl4030). Thus, as the USB requires between 4.75 and 5.25 volts,
so must be your supply for your application. Add a DC/DC converter between your battery
and the Tobi, it works great.