mini UPS for mini 2440

Hi, 
I have installed mini2440 in a kiosk, it has win CE OS running
and my software  on it. No need for monitor.
It only uses serial port and make the process.

Now my problem is that ; If the electric is gone, it should
be running for at least 2 hours.

I dont want to use its 5v 1.5A adapter.

I need a very small UPS (Uninterruptable Power Supply) just
similar like in PCs.

Can smo. please suggest me a hardware; but very very small in size.
when there is electric, mini2440 will feed from the adapter,
when there is no electric (220V), it will switch to battery,
should power for 2 hours.
It will consist of a charge adapter, rechargeable battery, and some
electronics card.
Do you know a ready mini-micro ups type, model that may be used for this
purpose?

Best Regards.

2 times 3.6V Li-Po cells in series of about 1500ma/H rating.  Run the
mini2440 off a 5V 1Amp LDO (appropriately heatsunk) and then a 220V Li-Po
smart charger capable of stuffing about 1Amp into the battery.

Maybe, a buck-mode SMPS might be more efficient, compared with the 5V LDO. 
One has to do the calculations.

No switching required. 

Is the mini2440 running all the time?  Someone listed the current the
mini2440 draws without monitor recently, so you can check the figures. 
1500maH should run the mini2440 for more than 2-3 hours.

Hi, 
Thanks, I know LiPO batteries from multicopters.
but their size is still large for me.

Yes, mini 2440 will run 7x24x365 ...  all the time.

I have found a mini ups type for another mini pc card;
http://www.mini-box.com/picoUPS-100-12V-DC-micro-UPS-system-battery-back...

I can reduce the voltage from 12V to 5V, no prob.

But can I find a battery which size is very very small,
Say a 1-2 series of AAA or AA battery sizes?
And capable of 2 hours working of course.