Powering GSM MS from USB

[Das Signal]

Hi Mychaela,

Although not an EE expert, I remember GSM phones from the late 90s
had a big capacitor inside, probably because the batteries at the
time were not capable of such high sure current. Then modern Li-ion
started becoming popular and the need for such capacitor lessened
afaik.

In theory you could add such a capacitor between 5v and GND although
it would technically not be authorized by the USB spec. But there
should be no issue as long as there is protection to the USB port
itself. But then again, I'm no expert on the suject ;-)

--DS