Arduino with an automatic, re-chargeable, battery back-up

Hello all,

I am brand new to Arduino and my first goal is to incorporate a battery back-up into the Arduino that is automatically utilized when the Arduino is unplugged, but is rechargeable when the board is plugged back in.

Here are my thoughts:

Can I use a sparkfun powercell: http://www.sparkfun.com/products/10300 with a li-po battery and connect the 5V output from this board to the Vin of the Arduino?

I know the powercell can provide 5V out and charge at the same time. So instead of powering the Arduino from it's own USB or barrel-jack, I would plug this powercell board into the wall and power the arduino from it. If the USB from the powercell is unplugged, the Arduino would be powered by the battery.

I have NO circuit design experience (yet) so I'm trying to do this as simply as possible.

You'd want to power this device from a 5V or 6V wallwart and connects its 5V output to the 5V header on the arduino.

olimexino-328 have build-in lipo charger and automatic voltage source switching

So I can power the Arduino from the 5V pin no problem? I have heard some debate about this

rturk3:
So I can power the Arduino from the 5V pin no problem? I have heard some debate about this

I believe so, as long as you are using 5V regulated, if not then use Vin pin. (Someone please correct me if I am wrong)

Are you looking to put something together or is a ready to go solution OK? I have been looking at the lithium backpack from liquidware for myself, which starts around $35, this might be an option for you.

rturk3:
So I can power the Arduino from the 5V pin no problem? I have heard some debate about this

The only debate I can think of is if you have both an external +5vdc regulated voltage applied to the +5v pin and you then plug the USB into a PC, then you have in effect two different regulated voltage sources hardwired together. That is not considered a good engineering practice, however many do it with no negative effects.

Lefty

I should be fine then because while in use the USB cable will power the Arduino through the powercell, vice having the powercell with battery power the 5V pin AND a USB plugged into the Arduino.

If I'm powering the Arduino through the 5V pin, how can I then power subsequent modules? This will eventually be a wireless RFID detector.