Hi, I need your help!

My UPS requirements are 2 Fans and 2 Energy Savers with 1 ptcl router. With 100 watts each for the fans and 25 watts each for energy savers, this is 250 watts load with another 25 watts(? not sure) for the router. So, I am hoping that a 650 VA/400 Watts UPS should cover me for the above load, right?

Accordingly I am interested in APC Back-UPS, 400 Watts / 650 VA. However, the RBC17 battery that comes with this has 108 volts-amps-hours. This volts-amps-hours value seems to be tiny. I am guessing that if it is 12 volt then the AH value would be 9? However, they list the recharge-time for this battery as 8 hours?!

So, my questions are

1. Why does it take so much recharge time for such a small capacity battery?

2. I am thinking of using this with the above setup with around 6 hours of load shedding. Will a much larger battery than the built-in one, around 120 AH work/suffice for my setup and load-shedding? What about the recharge time in my case?

Thanks a lot for your time!