Thread: My PSU is 145W, so I am assuming 150W inverter is ok

You might be just on the edge with a 150w inverter. I'd go with the 300 watt just to be on the safe side. There's really not much point skimping on inverter capacity, they pretty inexpensive anyway.

Also remember that a computer PSU will only draw the power it needs to use.

but surely the power supplies maximum usage is 145W, so it won't be actually using 145W all of the time. Therefore the 150W power supply should be able to handle it easily as that's what it is designed to do and wouldn't the 300W power supply use more of my car battery power?

No one is saying it won't work, but it will be working under 100% load, or close to it, all the time. That means more heat, and stress on the inverter. Also take into consideration that the wattage rating on any inverter is under optimal conditions. The excess heat, and the length and guage of your power cable to the inverter are going to hinder it's ability to give you a full 150 watts. Long story short - get a 300 watt and be done with it. And don't forget to run it directly from the battery, not the lighter.

Don't you need to calculate the power needs by how much it draws?

It's putting out 145w in the end, and PS's aren't all that efficient.

Originally Posted by Jizzler

Don't you need to calculate the power needs by how much it draws?

It's putting out 145w in the end, and PS's aren't all that efficient.

Yes that is right. If the PSU is outputting 145w (which is what that number means, OUTPUT,) then it will be drawing somewhat more power than that. Probably quite a bit more than 150w.



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