Bill's PriUPS

Bill has saved me a lot of trouble writing up his system. His Facebook page covers the system in more detail and with more photographs than I would put here. Quoting from his overview:

My Priups system. Consists of a Deltec 12 kilowatt computer room UPS, and a small Liebert 1400VA UPS to jump start the big Deltec. Because the Deltec isn't designed to cold start without grid power. You simply connect the Prius and hit its power button, start the little UPS after the power goes out, press a few buttons on the Deltec keypad, and 'voila, you have 10,000 watts of serious, stable power for as long as the Prius has gasoline. What is totally cool is that the Prius will only run its efficient engine so long as it needs, to maintain the battery.

He ran into the same problem that I did with respect to the Prius voltage being incompatible with the UPS battery supply. My UPS was content to run at a slightly lower battery voltage than his Deltec, so I only needed a 12V boost to the Prius battery. Bill used Vicor modules as I did to add 38 volts. His comments:

The Prius supplies DC power, ranging from 205vDC to 225vDC. My Deltec wants to see a very minimum of 214vDC and more if it can get it. So these way cool whiz-bang highly efficient Vicor brand DC-DC converters fill the need. Stepping up the Prius power by 38vDC. Need to add a few capacitors to the converters and they are ready for service. Installed them onto some scrap aluminum channels lying around in the workshop, and placed them inside the Deltec, directly in the airflow. It is overkill, but I needed to mount them somewhere.

And some new info from Bill for March 2010, with some clever mods to his UPS.

I had finally buttoned up this project for good (FINALLY)...and thought I would summarize for you. You may recall I used a 12kW Deltec unit that turned out to be a super unit to work with, especially since I obtained the schematics. I ended up removing the Vicors, they weren't even needed. All I had to do was modify the DC battery bus voltage monitoring op amp circuit (first revision was incorrect) such that its output was bypassed (switchable) in favor of a 1k pot, allowing up to 15vdc output to the cpu. Then I could simply adjust the pot to anything I wanted to, well almost. Anything over 300vdc caused a shutdown, so I set it at 297v or so, now the countdown to shutdown display varies from days to about 45 minutes, never below, based on the max 5.5kW I had loaded the thing down to. Should i need more adjustment, it also monitors the DC battery current, I could modify its circuit the same way.
So should you run into anybody else looking into using one of these, tell 'em it will work fine.

^New ^{24 March 2010}