Can I extend 800va ups run time? with extra batteries?

[devass]

I have a apc smartups + backup packs. Recently smartups died because of 3 mofsets died and apc trying to charge much higher price there visiting charge 800 Rs and to repair the product may cost 2000 Rs. I will just inspect the ups and repair it later. As of now.

I have 12v 9ah 6 batteries from APC backup pack and apc smart ups.

I am planning to buy http://www.amazon.in/Microtek-800VA-UPS/dp/B009CVTZCM?_encoding=UTF8&m=AQNMI0TASTTT4&ref_=v_sp_detail_page and by removing top shell adding this batteries in parallel to increase the run time of my pc. My PC consumes approximately 100w per an hour.

What do you guy's think.

There is already 12v 7ah batteries in this device. So total can be 8 number of 12 volt batteries will give me long run time.

 

[Alabalcho]

If the UPS is not designed to support extended runtimes, you might have problems properly charging the whole pack (base + extended). If you live adventurous life, you can keep these extra batteries charged separately, and connect them when necessary.