Hurricane Sandy - I love my Prius!

so..help me out... i understand that it is better to connect an inverter directly to the battery in order to eliminate the possibility of blowing a fuse in the Prius.. and I understand that connecting an inverter to the traction battery will produce even greater power.. what I want to do is have a moderate emergency source of power.. where I can charge a laptop, a phone, a modem and maybe run a TV.. I just want to have communication to the outside world if we are snowed in.. I don't need to power a fridge, or a bank of lights... I have a mountain home with stoves and fireplaces and plenty of lamps.. but we have been in situations where we have lost power for 2-3 days... I really don't need to invest in a generator.. what should I buy to satisfy my emergeny needs in this case?

 

a small inverter that plugs into the cigarette lighter would probably work. 500w maybe?

 

You cannot get 500W out of the 12V outlet. If you are lucky, 140W is about all you will realize (14V x 10A).

 

Randy, a 500-1000 watt inverter properly attached directly to the 12 volt battery. The Prius supplies the 12 volt battery from the traction battery via a ~1300 watt power supply. Would be perfect in your situation.

 

Sounds like an inverter connected directly to the 12V battery would make an ideal camping solution as well.

 

if something's wrong with this configuration, you are talking about a dead car and stranded in the wild.

 

I think the risks are pretty low, given the Prius' lack of off-road capabilities. Based on what I've read so far, it appears to be a pretty simple configuration. Of course, running out of gas is a possibilty if you're not a good planner.

 

Yeah, if you forget to turn the car ON, or let it run out of gas, you'd be boned. So don't do that :_>

 

My experience has been 2 gallons a day is a better estimate but as always, your burn rate will vary with load and temperature:

• ~6.3 gal/day @1 kW maximum load
• ~2.0 gal/day - April 2011 power outage, 4.25 days
• ~1.5 gal/day - idle, overhead

I do not have a Prius configured for fuel exhaustion testing when in generator mode. With the engine out of fuel, it risks draining the traction battery to the low limit, 40% SOC, and hopefully that would shutdown the car. But this is one of the 'forbidden experiments' as recovery might require a tow to a Toyota service center for traction battery recharging. In 2005, there were discussions in "Prius Technical Stuff" indicating there are only one or two such chargers in North America.

Bob Wilson

 

Bob:
You can make a very inexpensive charger. I built a simple voltage doubler, 2 diodes and a capacitor. I got a few amps out of it and charged the battery up for a few hours.

 

the doubler schematic.

 

It isn't the power supply, it is the connectors to the traction battery. Remember, not only do I need the ends but also a bridge between the two banks. This means pulling the traction battery and installing the wiring and connectors. I may eventually get around to it but it will be part of parallel effort to see if a 'topping charge' on the traction battery gives an expected MPG boost.

Bob Wilson

 

Bob:
I don't know about the Gen 1 and Gen 3, but on Gen 2, there is no need to pull the battery. Anyway, I was making the comment because of the need to find the 2 dealers that have chargers, when that seems not to be the primary issue.

 

I figure if I ever ran my traction battery down I would use my traction battery-to-UPS connection in reverse, using the UPS's charger to put enough into the traction battery to get the Prius started. Then I would let it recharge itself. I don't see this ever happening, I can run most of my house for 2 1/2 days on one tank of gas.

 

Power flows only one way, not in the reverse direction.

Bob Wilson

 

Not in my setup, take a look at the links I posted earlier. The traction battery is attached directly to a 4 kw UPS, which can backfeed using its built-in charger.

 

with al the DIY plugins on this planet this is pretty mutch covered right now ;-)

 

I understand.the plug-ins are not charging the traction batteries but they only provide power from the external batteries to prevent discharge of the traction battery. But it is an interesting question as there are risks charging NiMH without battery management to prevent overcharge and battery heating.

 

Just saw this post, I'm not sure that I did. Someone emailed me with questions about the APC UPS line, but I don't think I saw anything about your system.