Using the Volt as a backup power source.

solar_davesolar_dave Solar Expert Posts: 2,343 ✭✭✭✭
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.

Comments

  • BB.BB. Super Moderators, Administrators Posts: 29,489 admin
    Re: Using the Volt as a backup power source.

    With the Prius, you have two options... One was a 12 volt inverter and the high voltage battery kept the 12 volt battery charged--and started the engine when needed to recharge the high voltage battery (car had to be "on" to do this--as I recall).

    Or, there are larger (computer room UPS's) which can take the Prius high voltage output directly to the inverter.

    12 volt Prius Inverter setup
    ~240 VDC Prius Inverter Setup

    Something similar with the Volt?

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • UrbandialectUrbandialect Solar Expert Posts: 107 ✭✭✭✭
    Re: Using the Volt as a backup power source.

    I was thinking about this the other day, can't I just hook a inverter to my car battery and turn the car on and let the alternator charge the battery while i suck the juice out with a 1500watt inverters, I think a normall alternator puts out about 20amps, but i could be wrong.
  • solar_davesolar_dave Solar Expert Posts: 2,343 ✭✭✭✭
    Re: Using the Volt as a backup power source.
    I was thinking about this the other day, can't I just hook a inverter to my car battery and turn the car on and let the alternator charge the battery while i suck the juice out with a 1500watt inverters, I think a normall alternator puts out about 20amps, but i could be wrong.

    There are some high amp alternators on cars. The issue is they really don't put out the high potential amps until spun up pretty good.

    With the Volt the potential is to have 16Kw of battery available to DC-DC convert to 12V without running the ICE all the time. Mountain Mode is designed to recharge the Li battery with the ICE. Assuming conservative use of the 12V resource and having a TSW inverter with sufficient surge capacity one could only occasionally run the ICE.

    As always long term fuel is an issue.

    Love the inverter references BB :D
  • solar_davesolar_dave Solar Expert Posts: 2,343 ✭✭✭✭
    Re: Using the Volt as a backup power source.

    http://www.solar-electric.com/exxp12vol11w.html looks like it might fit the bill.
  • techntrektechntrek Solar Expert Posts: 1,372 ✭✭✭
    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!
    4.5 kw APC UPS powered by a Prius, 12 kw Generac, Honda EU3000is
  • waynefromnscanadawaynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    Re: Using the Volt as a backup power source.

    200 volts? Very interesting indeed. That's not all that far above the DC voltage generated inside many 12 volt inverters, that is then fed to the output switching transistors, at least with a couple of MSW inverters I played around with some years back. Forget the exact voltage though. I suppose there wouldn't be a big demand yet, but methinks it wouldn't take much for someone to come up with a relatively simple inverter that would take the 200 VDC directly and chop it up to make 60 Hz then perhaps use a transformer to take care of the slightly higher AC voltage.
  • techntrektechntrek Solar Expert Posts: 1,372 ✭✭✭
    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 "
    4.5 kw APC UPS powered by a Prius, 12 kw Generac, Honda EU3000is
  • solar_davesolar_dave Solar Expert Posts: 2,343 ✭✭✭✭
    Re: Using the Volt as a backup power source.

    Interesting, there is an unused 100 amp fuse location in the fuse box.

    So easily a 600W/1100W surge inverter should work and should not invalidate the warranty.
  • techntrektechntrek Solar Expert Posts: 1,372 ✭✭✭
    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."
    4.5 kw APC UPS powered by a Prius, 12 kw Generac, Honda EU3000is
  • TheBackRoadsTheBackRoads Solar Expert Posts: 274 ✭✭✭✭✭✭
    Re: Using the Volt as a backup power source.

    Not 210V, but Exeltech makes a 125VDC inverter....

    http://exeltech.com/xpspecs.htm
  • solar_davesolar_dave Solar Expert Posts: 2,343 ✭✭✭✭
    Re: Using the Volt as a backup power source.
    Not 210V, but Exeltech makes a 125VDC inverter....

    http://exeltech.com/xpspecs.htm

    Well I am looking to just cover my bare needs while not invalidating my warranty. Looks like the 12V 100amp fuse box tap is the way to do that. And I found out the DC-DC converter is limited to about 2Kw/175amps.
  • techntrektechntrek Solar Expert Posts: 1,372 ✭✭✭
    Re: Using the Volt as a backup power source.

    The Prius' DC-DC converter only does 100 amps, which limits it to the 1000 watts from the 12 volt system (leaving 200 watts for internal use). If the Volt does 175 amps you can go up to 1500+ watts w/o a problem.
    4.5 kw APC UPS powered by a Prius, 12 kw Generac, Honda EU3000is
  • snuffysnuffy Solar Expert Posts: 72 ✭✭✭✭
    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.
  • mike95490mike95490 Solar Expert Posts: 8,370 ✭✭✭✭✭
    Re: Using the Volt as a backup power source.
    snuffy wrote: »
    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.

    Just be sure to leave the garage door open, or park outside :D
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • solar_davesolar_dave Solar Expert Posts: 2,343 ✭✭✭✭
    Re: Using the Volt as a backup power source.
    techntrek wrote: »
    The Prius' DC-DC converter only does 100 amps, which limits it to the 1000 watts from the 12 volt system (leaving 200 watts for internal use). If the Volt does 175 amps you can go up to 1500+ watts w/o a problem.

    True but this requires a battery tap and a fusing setup accordingly. Not that that is bad but if I can power my minimums with a 600w/1100watt surge inverter then the easy and warranty safe way would be to use the 100amp fuse box tap which is fused internally.
  • snuffysnuffy Solar Expert Posts: 72 ✭✭✭✭
    Re: Using the Volt as a backup power source.
    mike90045 wrote: »
    Just be sure to leave the garage door open, or park outside :D
    Of course if I could afford a Volt...
  • techntrektechntrek Solar Expert Posts: 1,372 ✭✭✭
    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.
    4.5 kw APC UPS powered by a Prius, 12 kw Generac, Honda EU3000is
  • solar_davesolar_dave Solar Expert Posts: 2,343 ✭✭✭✭
    Re: Using the Volt as a backup power source.

    There is a pretty good discussion of doing it over here http://gm-volt.com/forum/showthread.php?8835-Volt-as-Emergency-Power-Generator&highlight=Inverter

    It is easy to add a 600/1200 watt inverter into the 100 amp unused accessory fuse box location. The 12 volt charging system is rated at 175 amps so turn on the car and turn on the inverter and good to go. The car will then manage the main battery as it gets drawn down.
  • techntrektechntrek Solar Expert Posts: 1,372 ✭✭✭
    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.
    4.5 kw APC UPS powered by a Prius, 12 kw Generac, Honda EU3000is
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