Using a Prius as a Backup Generator, Any Changes?

<div class='quotetop'>QUOTE(Virodeath @ Sep 18 2007, 06:05 AM) [snapback]514204[/snapback]</div>

I think you may be referring to the thread I started on the subject of "Prius as a power source" about 13-14 months ago. I don't know how to give a shortcut to it; I usually do a search for "power source" to find it. There is a lot of discussion there, but perhaps it's time to start a new thread.

I believe the house on the NAV screen was simply Mr. Factor' artistic rendition, intended to punctuate his project, but that does not diminish the validity or the value of his work.

There are several Prius owners that have tapped into the HV battery, and I am among them. There are several methods (none of which are condoned by Toyota) to utilize this power, depending upon what you want to accomplish. A small system can run the refrigerator and a furnace or a large system can run just about everything. Keep in mind that there is a certain amount of power consumed, even when no AC power is being drawn, as fans in the UPS units contine to run, and I suspect that the UPS itself must consume a certain amount of power to be "ready", as heat is generated. Bigger isn't necessarily better, unless its efficiency is much improved over the smaller systems. (And it may actually be better, as the smaller systems in Mr. Factor's work required switching power supplies, and so some efficiency is lost in that conversion.)

For me, the biggest task was to attach a cable to the HV battery. I made my connections to the switched side so that I'd have power only when the Prius is "on". My goal was simply to have the ability to run my household appliances (except A/C) on PriusPower in the event of an extended power outage. I don't intend to hard-wire another fuse panel; I'll just trip over extension cords for the duration of the outage. I acquired a Tripp-Lite SU6000 [6,000volt-amps/4,200 watts] and a conversion transformer. This unit can be "cold started", an absolute 'must' when the utility power is out. I simply connect my Prius cable to the Tripp-Lite, hold the Start button for 3 seconds, and I've got both 120 Vac and 240 Vac power available.

 

<div class='quotetop'>QUOTE(Virodeath @ Sep 18 2007, 06:05 AM) [snapback]514204[/snapback]</div>

There are websites, such as www.PriUPS.com that give insight on how to do this, but it's meant for the hacker with electrical experience, particularly an understanding of power supplies. I don't know of a step-by-step guide that details exactly what to buy and has pictures of each modification, a "dummy's guide" if you will.

I would like to do this as well, but the easier solution is to tap off the 12V aux battery, not the HV traction battery. It can still give you about 60 amps x12V = >700 watts. Unfortunately my furnace uses a maximum 1100 watts according to the spec, I'm not sure if that's on startup or on high (it's a two-stage gas furnace), so I'm debating if it's worth it to run my sump pump and refrigerator, or should I spend the time to get comfortable with hacking into the HV system.

 

<div class='quotetop'>QUOTE(Virodeath @ Sep 18 2007, 07:05 AM) [snapback]514204[/snapback]</div>

It's not a how-to, but the NY Times had an article about this a little while ago. You can find the article on this PC thread:

http://priuschat.com/index.php?showtopic=38152&hl=

 

<div class='quotetop'>QUOTE(Virodeath @ Sep 18 2007, 09:49 AM) [snapback]514266[/snapback]</div>

 

<div class='quotetop'>QUOTE(Virodeath @ Sep 18 2007, 09:49 AM) [snapback]514266[/snapback]</div>

No, TrippLite's system comes in three units: Power Module, transformer, and battery unit. The SU600RT3UPM is the Power Module (that's the 'PM' after the '3U', and 3U designates the height of this rack mount unit). This Power Module ("PM") can be connected directly to the Prius HV battery, and the PM produces 200 or 208 or 230 or 240 Vac output. If you're trying to run most appliances, furnace motors, etc., you'll need to drop the voltage down to 110-120 Vac.

That's where the transformer unit comes in. It accepts the 200+Vac input and gives out 110-120 Vac AND 200+ Vac. I also acquired one of the TrippLite plates with recepticles on it, but without the plate, you can always wire up your own distribution box. The transformer unit gives two 120 Vac circuits and one 240 Vac circuit.

Unless you want to be able to run your setup for a while before you connect the Prius, you don't really need an expensive and heavy battery pack. As I mentioned, if you intend to actually use the system as an uniterruptible power supply, then you'll need the battery pack for the instantaneous transfer it provides.

My parts list is short: I connected a four foot length of #10 wire to the relay side of the HV battery, attaching heavy lugs to the wire. Mine's an '06 Prius, so it has short studs to connect to, so I had to remove the existing nuts and add my connection beneath them, then reapply the nuts, tightening them to about the same tightness, as I don't have a small torque wrench. The other end of the wire gets an Anderson Power connector.
For my testing, I used solid 12 gauge wire to connect to the PM. The transformer module connects directly to the PM, so, when I Cold Start the PM, the transformer puts out usable 120 and 240 Vac. Plug into the outlets (or wire the transformer to a distribution box), and I can run whatever I want, up to 4,200 watts.

I intend to run a permanent wire through my garage wall into the basement so that I can coil the wire in the garage and plug it into the Prius for those rare, extended power outages.

By the way, I'm told that the SU5000 and SU6000, which both normally utilize a 240Vdc battery pack, can be operated on voltage as low as 200-205 Vdc. Today I've inquired of Tripp-Lite what the High Voltage Cutout point would be, as someday, somebody with a Highlander may be building a PriUPS system (HyUPS??). Or maybe someone with a Classic whose battery is what, 273 Vdc?

 

<div class='quotetop'>QUOTE(nerfer @ Sep 18 2007, 09:25 AM) [snapback]514252[/snapback]</div>

Before I ventured into the Deep Waters of the high voltage UPS, I used a 1,500 watt/3,000 watt surge inverter, but I put a buffer battery into the line instead of the miniture Prius 12v battery. I attached a new cable to the positive side, and attached another cable to a ground (but not the battery's negative post). I then used a deep cycle battery that has two sets of terminals. I attached my new cables to one set of the terminals, and attached the inverter to the other set of terminals. I figured that the deep cyle battery would provide the surge power needed while providing a buffer to protect the Pruis' battery. The HV battery keeps my deep cycle charged, and Pruis starts itself to recharge the HV battery.

A couple of important points should be made. First, like most inverters, my inverter is a "modified sine wave" inverter. Some motors will not start or run properly or overheat on the modified sine wave. Floresent lights are noisy. Also, the Pruis 12V system has an internal limitation of about 1,000 watts. If you try to draw more than that, Pruis will cut voltage/increase amperage to maintain the limit. This can blow an expensive fuse if you're not careful. I'd recommend seeing if what you want to run will run off of an inverter before deciding to use the Prius to provide the 12 volt source.

 

Another good thread on this topic here is My Prius is Powering my House

 

With all the recent weather related power outages, perhaps it is time to update this thread to see if there are any new developments in this area. It sure would make another strong selling point (as if they needed one), if the new Prius had a factory option to let the plugin model 'reverse', and put ac power back into the home.
I believe Chevy Silverado trucks have an option for a more limited power source from the truck to operate certain power tools, etc.

 

I replaced my 12volt with an optima yellow top because of using a wheel chair lift and then bought a 1200/2400 Inverter hooked to the optama that will run 1200 watts of power by leaving the ice in ready> works for small appliances and tv ,lights etc/

 

will it run a refrigerator?

 

I was thinking of using the full power that the ICE/generators could deliver constantly. I wonder how many kw that would be? And how many gallons of gas per hour would it burn at full load?

 

Toyota claims 73kW @ 5200 RPM.

If you need anything like that much, you have bigger problems.

 

This would sell a Lot of Prius's In Rural Areas!

 

The ultimate resource on installing a high power inverter in a Prius is:

PriUPS-getting electricity FROM your hybrid vehicle

The actual limits are probably:

• Absolute limit - the 25kw capacity of the battery (100 amps at a little over 200 volts).
• Battery heating limits -
  • Peak - about 6kw
  • Average - about 3kw

JeffD

 

we have a 5kW propane generator. it works out well because we are on propane anyway and have 2 100 gallon tanks in the yard. 5 kW runs the frige, oil fired boiler including hot water, well pump and various lites and outlets in the house. cost was $6,000. installed and if i had known i could have done it with the prius for $2-4,000. in 2004 when i had the generator installed, i would have done it in a heartbeat. the only question i have is how long will it run on 8 gallons of gas?

 

8 gallons of gas contain about 250 kWh of energy. Minus efficiency losses of course.

 

that sounds like about two days on average, that wouldn't be bad at all. the nice thing about the prius is, it supplies electricity as needed. so, in theory, eight gallons could last indefinitely. whereas, my generator runs continually unless i shut it off manually. which i do.