# (HELP) Inverter for Gaming Cafe: How long will it last?

#### billubakra

##### Conversation Architect
I would suggest you to get individual ups for each of the pc's. Buying in bulk will fetch you some additional discount too. If that Luminous inverter has some issue then none of the pc's will work whereas in the individual ups case that won't be an issue. Battery backup on a single ups will depend upon the size of the monitor/speaker/accessories etc. connected to it. More or less about 10 minutes. Wait for others to reply.

#### patkim

##### Cyborg Agent
I am not an Electrical Engineer! So, use your discretion if you want to follow any of my advice. The Luminous UPS product page that you have linked in your post, if you just scroll down on that page, you will find a link named Buying Guide. Access that page and then from left pane select VA Rating for UPS & Battery for UPS links.

These pages explain the relationship between Watt/ VA/PF/Battery Voltage/Battery Current Capacity and duration and also explain the basic formulas needed to calculate them.

Study the formulas given therein and you can work out the basic math yourself. For general calculations you may consider power factor (PF) of around 0.7 to 0.75.

Just in case those links go dead in future, here are the formulas as described by Luminous on their website.

Code:
``VA = Power in Watts / PF  ( PF is between 0 thru 1)``

Code:
``Battery capacity Ah= (Power requirement in VA * Back up duration in hour) / Battery Voltage (in volts)``

However I suggest that if you are really investing in such a business of cyber café/gaming café then hire a professional or check with your UPS vendor if they provide a professional who would access your proposed setup, total load, expected backup duration and evaluate the parameters like power factor, number of batteries needed and other such details more technically and provide most optimum power backup solution for your setup.