Hurricane Ike & Prius Power

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

 

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

 

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

 

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

 

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.

 

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.

 

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

 

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?

 

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

 

if you have natural gas, its a better deal to invest in a 15kw or 11 kw standby generator with transfer switch.

 

We do have NG, but we don't get outages often enough where we live to invest $2K in such a generator. But I can see the advantage of that option.

Bob, what kind of permanent connectors did you use? Any recommendation?

 

First I worked out the mounting for the inverter in the car. Are you planning to keep it in the car or in and out as needed?

In my first hookup, to a 2001 Echo, I installed the ground cable in the engine compartment and the hot wire on the inverter B+ terminal. Then when I needed the inverter, I connected the B+ to the battery terminal and then hooked up the ground wire. I didn't bother with a socket since I'm handy with a wrench.

Bob Wilson

 

I recommend Anderson Powerpoles for connectors. You can put 45 amps through the smaller ones; that should supply about 350 VA or 250 watts. They make a bigger one (75A) that will handle about twice that.

For up to 250 watts, 10-gauge wire should do on the very short run from the battery to a connector. The problem with PowerPoles is that it's hard to find a place to buy just a couple of sets; usually they're packaged in bags of 10 or 12.

You might take a look at West Mountain Radio - Pricing & Ordering - United States 48 States and check out the Powerpole to Ring Terminal 6 ft Batt Fuse Cable which looks like it would do the job. They don't say that they used 45A contacts on this, so I'd ask first. Of course you'll need to replace the connector on the inverter with Powerpoles too. Further down, you'll see several other varieties of connectors. I'd avoid "cigarette lighter" connectors for inverters over 100 watts; they get too hot because they don't have a secure contact.

Regarding natural gas inverters for home use: these are nice, but here in California when the Big One arrives, the gas is going to go out too. Prudence dictates we keep the tank more than half full, but that means twice as many entries in the little book, so maybe I'll just siphon some out of the Caravan when that day comes.

 

Actually you do. Hopefully you know that the MFD debug screen allows you to monitor the 12V battery voltage.

Toyota Prius Controls

Undocumented Custom Menus on the 2004 Toyota Prius

12 Volt (12v) Toyota Prius Auxiliary Battery for 2000, 2001, 2002, 2003 with installtion kit and free shipping to 48 states

 

One late thought, make sure your inverter does NOT rest on a carpet. Although the inverters are fairly efficient, they do get hot and a carpet surface blocks heat transfer. Put it on a cookie sheet, a cake pan or elevated at least 1/2" above any carpeted or insulated surface. They need air cooling.

Bob Wilson

 

since the high voltage battery is about 200 volts DC... is it possible to hook up two modules in paralell, giving 14.2 volts, and having all of the 28 modules producing the 14.2 volts while still having the cars 201 volt series connections? then using the 14.4 volt power to a high wattage inverter ( 6000-12000 watts )?

i was also looking at my honda accord hybrid battery, although its not as powerful as the prius battery each module gives 1.2 volts ( 120 modules in total ) , therefore i can have 12 sets of 10 modules hooked up in paralell giving 12 volts to a UPS or a inverter.

 

Is it possible? No.

 

Come to think of it, I already have 4-gauge hot and ground wires connected to a PDB in the hatch box for my amp and two cooling fans. It should be no problem at all to hook up an inverter to the PDB - either permanently or on demand. The fans will help dissipate heat. Of course, if I need to use the inverter during emergencies, the amp and stereo system will be turned off.

 

You can use the mechanical key to lock the car with it running. I do it all the time in order to have the air conditioning run while I'm in a store. Electric air conditioning is really slick!