Hurricane Ike & Prius Power

[drewtx]

I live in Pearland TX - about 30 miles inland of Galveston where hurricane Ike made landfall. We have had no power since 9pm Friday; almost 6 days.

Our house is OK and we have full regular water and gas supply – so power is our only significant problem. Within 24 hours of losing power our biggest challenge was to charge our cellphones so that we could keep in touch with friends and family (and so that I could use my Blackberry to post to my blog).
We didn’t have a car charger for my son’s iPhone so I dug out an old inverter that I had bought a few years ago; one of those things that you plug into ‘Cigarette Lighter’/Accessory socket in a car and which gives you a 110v AC supply. That worked fine; iPhone was getting charged on a regular basis.
Then it struck me: I wonder if I can use my Prius as a generator?

I know that the hybrid system will cycle the gas motor to keep the hybrid battery topped up, but I didn’t know if it would do the same to keep the 12v ‘Accessory’ battery topped up.

Well, I’m happy to report that for the last 4 days we have been running on Prius Power at home :-)

The inverter is only rated at 100w, but that is enough for a small LCD tv, a 10w cfl light and a Wii at the same time :-) I plug the inverter into the car, run an extension cable in to the house and plug in our various devices. I start the Prius and just leaving “running” (in driveway, not in garage - to avoid fumes). Of course, as usual, the gas motor shuts off pretty quickly if the vehicle is stationary, but the gas motor starts up and seems to keep the 12v Accessory battery charged fine.
I don’t have any way to verify that the 12v battery is actually being charged, but we’ve run our gadgets for long enough that I’m sure they would have drained the 12v batter had it not been getting charged.
I gotta say, this is PRETTY COOL! Waaay quieter than running a stand-alone generator in the driveway, and of course the Prius only runs the gas motor when it needs to top up the 12v battery whereas a stand-alone generator would be running non-stop.
I don’t know if this could harm the battery or Prius – but I doubt it. Heck, even if it does harm the 12v battery, that’s a pretty small price to pay to bring some civilization into our lives when we’re without power.
If you are currently without power due to Ike (or any other reason) or are in an area that can be impacted by power outages, I would recommend you add an Inverter to your emergency kit. I just bought another one today from RadioShack; 350w for $60.

I have a question:
I leave my Prius running in the driveway. I obvously don't want to leave the keys in it in case somebody jumps in a drive off with my car. So I took to hiding the keys CLOSE to the car but not actually in it (my thinking here was that the key would still be 'within range'). As it turns out though, I can bring the keys inside the house and the car still keeps running.
I wonder how far away the keys can be from the car before it will stop?
Could somebody jump in and drive my car 200 miles away? (as long as they didn't stop it and then try to restart it)

[V8Cobrakid]

the car will never stop. if someone breaks into it, they can drive off until they power off.

neat story. i have used my prius as a generator for my parents motor home. the built in one is soo noisy

[miscrms]

I couldn't help thinking, as we watched the news coverage, if only those people had Priuses 100W should be fine from the cig lighter, but your 350W you should put straight on the 12V battery. It will draw up to 30A, and I seem to recall the cig lighter is only good for about 10A. Ideally you should put an inline fuse on the inverter if you attach right to the battery posts. 50A would probably be fine, I believe the charging system is ok up to 100A. Your battery and car should be fine. The 12V battery isn't cycling at all really, as the dc:dc converter from the HV battery is really whats supplying your current. The HV battery will be cycling, but as you found the car just starts up the ICE to keep it in a safe range so all should be well.

There are folks out there that have I believe gone up to around 1kW off the 12V system, and ever higher off the HV system directly.
The Correct Answer
Prius - UPS Project
Charlie's PriUPS
Chris's PriUPS

Nice work, and glad you are safe!

Rob

[miscrms]

BTW one more thing to be aware of is the difference between cheaper "modified sine wave" inverters, and more expensive "true sine wave" inverters. The cheap ones use kind of a chunky waveform, which is fine for most stuff but may cause problems in others. I believe most small electronics these days that convert to dc anyway should be fine. Some AC motors, like fans or compressors may freak out. There shouldn't be any damage as long as you notice that its buzzing or not running right and stop it.

I'm not an expert at all on what things are ok and not ok with each, I just know its something to watch out for. I'm sure a google search will quickly illuminate the topic.

Rob

[bwilson4web]

When using a modified sine-wave inverter, you need to test your loads BEFORE an emergency:

• fans and compressors - use a thermometer to measure the AC, steady state temperature and then the inverter powered temperature. An increase of 5-10F is no problem.
• inrush - TVs and laptop power supplies can have a significant inrush. In those cases, you'll need an in-rush thermistor in a 'pig-tail' configuration. Test before the disaster

If you still have an inrush problem, one option is to buffer the modified sine-wave into a UPS unit. You'll lose some efficiency but you'll have the UPS for startup surges.

Bob Wilson

[Jack66]

Drewtx, I am glad you and your family are OK. It is great that your Prius can be more than just a car during this crisis.

Regarding your fob question: as configured, your fob is required to start your Prius, unlock the doors, and lock the doors. The fob only has to be in range to do these operations. You can walk away with the fob and you will hear a few beeps. The Prius will remain running but it is telling you the engine is on and the fob has left detection range. Anyone can jump into your Prius and drive it away but they can't lock it and they can't restart it once turned off without the fob coming back into range.

[zenMachine]

I've skimmed through the sites linked to above and found it to be too much info and more than what I need, which is some relatively simple solution that can be assembled and disassembled quickly in case of emergencies (which don't occur very often). The system should be scalable depending on what you need to power. At the very least it should be able to run the refrigerator, the Internet router, a TV, a laptop, and charge the phones. Everything else we can survive for a while without.

Is there a succinct write-up somewhere that explains what all one needs for something like I described above, and how to hook it all up with a Gen 2 Prius?

Thanks.

[qbee42]

Originally Posted by zenMachine

<snip>
Is there a succinct write-up somewhere that explains what all one needs for something like I described above, and how to hook it all up with a Gen 2 Prius?

Thanks.

What you need:
1) A portable inverter. True sine wave is preferable. Total up your wattage needs and buy accordingly, but I wouldn't go above 1000W.

2) Alligator clip leads to connect the inverter directly to the 12V battery.

3) An extension cord.

Keep the inverter close to the battery, and use an extension cord on the 120VAC side. That will keep the losses to a minimum.

Since this is for emergency use only, when you need to use it, open up the battery compartment and clip directly to the battery lugs. If you want to use it on a regular basis, install a socket and fuse.

That's all there is to it.

Tom

[zenMachine]

Originally Posted by qbee42

... when you need to use it, open up the battery compartment and clip directly to the battery lugs. If you want to use it on a regular basis, install a socket and fuse.

That's all there is to it.

That's pretty succinct. You only forgot to mention "don't forget to turn ON the car!"

What kind of socket are you talking about? Is this something to connect semi-permanently to the lugs, with an inline fuse?

[bwilson4web]

The only problem with 'clip on' leads is they tend to run pretty hot when drawing a significant amount of power. Heat is bad.

I went with a permanent cable connection to avoid the problems of clip-ons. But to each their own.

FYI, 1 kW @ 13.3 V is ~75 A. ... these are arc welder currents so the better the connector and cable, the less likely to have a 'welding' and 'hot smoking wire' problem. An electrical fire in a car is nasty business especially if you are already dealing with an emergency situation.

Bob Wilson