The ASUS Power Pack is an optional extra. Your G10 doesn't have one if you didn't specify it when you ordered the PC. But you've already got the APC UPS anyway so I don't know what you are bothered about. You don't need both of them.
I don't think the ASUS Power Pack can be bought on it's own, but to be certain about that you'll have to contact ASUS and ask them.