Parts for a UPS for a 5v device?

I want to make an uninterruptible power supply to work as a backup in case of power outage for BeagleBone Black, which will consume about a maximum of 1A (or slightly more) at 5V. I have a 3.7v lipo battery with protection circuit, a charger [1], and 1A lipo-to-5v DC booster. I wonder what other parts will I most likely need for this? A diode? P-channel mosfet?

[1] - http://www.ebay.com/itm/5V-Micro-USB-1A-18650-Lithium-Battery-Charging-Board-Charger-Module-Protection-/400665520672?pt=LH_DefaultDomain_0&hash=item5d4986aa20

in case of power outage for BeagleBone Black,

Had you not noticed this is an Arduino forum?

Maybe something like this.

Is this a cleaver bit of spam :)

Riva: Maybe something like this.

Yes, probably something like this. I saw it before, but I want to make my own or at least find out a bit how it works.

Here's its big picture: https://learn.adafruit.com/system/assets/assets/000/017/569/original/adafruit_products_1944demo_ORIG_300.jpg?1403303436

That A6K part to the left is a pnp transistor? Looks like it doesn't handle much current? So what does it do here?

And what is that part a bit to the right named "KDY3"? And what it's for?

The rest interesting stuff as I see it is a charging IC and a booster.

A6K is a transistor for driving the LED. KDY3 is the LIPO charger chip. You will find all the details and the schematics on the Adafruit site.