I have a 5000 VA UPS which is connected to eight 65 AH batteries. I am looking to replace these old batteries with new ones. I was wondering whether the UPS will run safely with less number of batteries or with less battery capacity.
I did some research and found out that the formula for calculating the battery capacity goes something like this:
Battery capacity = (Load / Voltage) * Back up time
I am assuming that the load is 5000 VA which will roughly convert to some 4000 Watts and its a 12 V battery. The back up time required is 30 minutes.
So battery capacity = (4000 / 12) * 0.5 = 166.
Is my formula wrong? I don't have an electrical background. Any help would be appreciated. Thanks.