Power outages are quite common here(india) and I want something better than a UPS: I don't wanna shut down the system. I was quiet inspired by Make Your Computer UPS Last for Hours that uses a car battery with a UPS. I was wondering if I could save on the DC to AC conversion and back and make the battery last longer.

I could not find anything on how laptop power supplies work but I am assuming they are more effecient.

  • \$\begingroup\$ Laptop power supplies are often ~19.5 V DC in, so your concept would work. \$\endgroup\$ – Brian Carlton Jun 28 '17 at 0:31
  • \$\begingroup\$ In order to give a helpful answer, you need to supply more information about your computer's power supply requirements. Your concept is generally a sound one, as you may be able to avoid the inefficiency of a double conversion. \$\endgroup\$ – Glenn W9IQ Jun 28 '17 at 10:53
  • \$\begingroup\$ I am trying to run a two gpu setup on a standard cpu so my current requirements are quiet high almost 500w. And im interested in heavier and more commercial applications as that is where those inefficiencies would really scale up. \$\endgroup\$ – praneeth mendu Jul 3 '17 at 23:54

Car batteries emit hydrogen gas and contain acid that can be VERY dangerous for children and pets, so they are not a good choice for using inside of your house. Gel cel batteries are what are used in small desk-top UPS systems, they are a lot safer.

The DC voltage into your PC must be regulated to within a fairly tight band and as batteries drain, the voltage drops. So you need a voltage regulator / DC to DC power supply. Plus you would also need a float charger.

But if you are going to do that, just get a bigger UPS!

  • 1
    \$\begingroup\$ AGM batteries are now quite common. The do not off gas in normal operation. \$\endgroup\$ – Glenn W9IQ Jun 28 '17 at 10:50

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.