Using the Volt as a backup power source.

Re: Using the Volt as a backup power source.

Its been a while since I've read the Priups site (the 2nd link that Bill posted above). From what I remember the guy ran lots of load tests to determine the largest load he could run from the 12 volt system, and the largest one he could run directly from the traction battery (roughly 200 volts DC). The 12 volt system was around 1000 watts, I don't remember a number from the traction battery.

After a quick search I don't see any references online where someone has done this with a Volt yet. You may have to break new ground and run the tests yourself - see the Priups site for guidance. Post back with your results!

Re: Using the Volt as a backup power source.

Or just buy one of the commercial-grade UPSs that take 192 volts nominal as their input, they can be quite cheap used. That was the original reason I bought the one I use ($200 ebay score), but I decided to go with an external battery pack instead of tapping into my wife's Prius. Only downside to some of them is they require an external AC source to start, no black starts from DC. Some are fine with DC-only.

I just did a quick scan through the Priups site and found this line which answers a few questions:

"Electrical testing using a "dummy load" indicates that one can draw about 5-6KW of electrical power at ~220VDC "

Re: Using the Volt as a backup power source.

Just found more info:

"...The tests I have performed appear to confirm the possibility of using the Prius as a source of electric power, with a 5kW rating and a voltage output nominally between 210 and 235V (at the vehicle terminals). I further found no reason why this power can't be taken "continuously" as long as the gas tank is periodically replenished.

The actual tests were limited to 2.4kW and 30 minutes and the above conclusion was extrapolated from them for the reasons given. Additionally, because the power is coming primarily from rechargeable cells, and their circuit is fused at 120A, it would seem that there is the possibility of taking peak power of at least 21kW (based on the specifications) and possibly even more for very brief periods. This assertion has not been tested by me-I don't have enough plywood to mount all the lightbulbs."

"Elsewhere on this web site I've taken to recommending 3kW average power maximum. This is based on the fact that Toyota themselves have mentioned this figure in an experimental house-power project, and discussions with a number of people who are concerned about thermal overload. I share that concern absent further tests or the availability of detailed specifications. Because of long thermal time constants, I still see no problem taking much higher peak power, or 5-6kW for reasonable periods as long as the average isn't exceeded long-term."

Re: Using the Volt as a backup power source.

solar_dave wrote: »

The recent hurricane got me thinking, the Volt has a large Li battery that keeps the 12 V system charged while it is set to "power on" and can fire up the ICE automatically to charge the Li. As a bare minimum what would it take to run a energy star fridge and freezer off a TSW inverter. I suppose in a pinch one could run the freezer a couple hours at a time while powering off the fridge. The starting surge would be the limiting factor I am sure.

In my case I have a battery bank I charge from my solar array then use an inverter to run a freezer and fridge. If the Volt battery voltage is under 250 VDC I could use a Midnight Solar Classic 250 and connect the 'Volt' battery to the input of the 250 and use it like a solar array to keep my battery bank charged.... connecting the output of the 250 to my battery bank.

Re: Using the Volt as a backup power source.

Dave, looks like another hurricane on the horizon. Any progress turning your Volt into a $41,000 1kw hybrid genset? :-)

Since this thread started I've been reconsidering adding a tap on my wife's Prius' traction battery and running some tests. With the potential to run 3-5 days on one tank of gas that would be far cheaper than my big genset. My current plan during a long outage is to run the big guy 8 hours per day and the inverter for 16, but if I add the Prius in to the mix I could get the genset down to 2-4. I might even try tieing the traction battery into my battery bank (instead of disconnecting the battery bank). With a Prius system voltage of 210-235 that would be a reasonable 13.1 to 14.6 volts per battery. My only worry would be the max amperage when charging.

Re: Using the Volt as a backup power source.

I know it can be done, I was curious if you did it yet.

Edit, I just read that gm-volt thread, I love the disclaimer the Volt customer service agent posted at the end.