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m11939 · 11-15-2011, 10:35 AM

In 2011, we have been hammered with Irene and Lee and a spooky Halloween weekend snowstorm up here in the Northeast. Each has caused its share of damage and power outages. I was lucky and only lost power for about a day and a half where I live during Irene. But during the snowstorm, many folks in CT and MA were without power for a week or more. All of this has got me thinking about backup power systems.

I have a 5000 watt generator which until this year, I have never really had to use. I connected it during Irene so I could pump water from my deep well and run my refrigerators and otherwise live normally. However, I quickly learned that the thing is a complete gas hog, using upwards of a half gallon an hour under low loads. It's also a bear to set up. I need to roll it away from the house on an unpaved driveway and over a lawn to get it in a safe spot to run it. That is quite a struggle and I'm not getting any younger. I figured there has to be a better way.

Searched the font of knowledge and discovered Bob Wilson's well documented inverter system in his 2003 Prius. Decided to give it a try on my 2010 Prius as I too happened to have an inverter (Portawatts 1750). However, I only tested it with a small load...about 300 watts. I just wanted to see for myself what would happen and indeed, the car ran every so often as I tested the power for about an hour to running my laptop, TV, CFL and regular fluorescent lights and other small loads I might want to use during an outage. All worked great!

OK, so I had my little power "appetizer" but now I too would like to have heat in a storm as a next step. Using an Amprobe, I determined that the furnace's largest load was when it starts the 1/2 HP blower motor, 10 amps for a few seconds. Then, the load drops off to about 6.5-7 amps for the remainder of the heat cycle.

Checked the fusible link in my Prius and it says its 140 Amps...not 100. (I took a pic but as a new poster, the forum won't let me post it.)

Tried to find out more info about this on the Internet but have had no luck. My guess is that the 2010 Prius' DC to DC converter can provide more power than the 2003's but I want to be sure. I would need about 1200 watts for a few seconds to start the furnace blower. That would be 100 Amps at 12 volts. This is more than Bob could get during his 2003 heater load test. (Bob: BTW, what does your 1/3 HP furnace motor draw when it starts?)

I've also got a 700 watt rated microwave that draws about 9.5 amps for about 1140 watts. It certainly would be nice to be able to use it...when the furnace wasn't on, of course. Again, 1140 is more than Bob could get with his 2003, but IF I have 40% more with the 2010 (1400?), maybe I'm not getting too greedy.

I like the idea of only using as much gas as I need and not really having to set the thing up. I mean, I park the Prius 10 feet from the house normally. During Irene, there was no way I could easily set up the portable generator during the storm. The rain was coming down sideways...for hours. The generator and I would have gotten drenched. But if my Prius had an inverter mounted in the back like Bob's, I'm sure I could have found a couple of dry minutes early on in the storm to connect a cord and run it into the house. Juice!

As Henry Petroski has pointed out many times in his books, "There is no perfect design". Using the Prius for something it wasn't intended has its limitations and risks. However, putting it to work on an emergency basis for light loads has a lot of appeal to me. I have no plans to sell "the monster" but I'd sure like to use it a lot less...maybe a couple of times a day for 15 minutes or so to take a shower or do the dishes. It would be nice if the rest of the day I could have peace and quiet...and save gas!

Anyway, if anyone can shed any light on whether the 2010 Prius indeed can provide more power from the DC to DC converter than the 2003, that would be great. Also, if anyone else has setup their Prius the way Bob has and has any experience with either running a 1/2 HP furnace motor and/or microwave oven with it, I'd like to hear about your experiences. Thanks.

11-15-2011, 10:35 AM	#23 (permalink)
m11939 EcoModding Lurker Join Date: Nov 2011 Location: Upstate NY Posts: 2 Thanks: 0 Thanked 0 Times in 0 Posts	2010 Prius as emergency power source In 2011, we have been hammered with Irene and Lee and a spooky Halloween weekend snowstorm up here in the Northeast. Each has caused its share of damage and power outages. I was lucky and only lost power for about a day and a half where I live during Irene. But during the snowstorm, many folks in CT and MA were without power for a week or more. All of this has got me thinking about backup power systems. I have a 5000 watt generator which until this year, I have never really had to use. I connected it during Irene so I could pump water from my deep well and run my refrigerators and otherwise live normally. However, I quickly learned that the thing is a complete gas hog, using upwards of a half gallon an hour under low loads. It's also a bear to set up. I need to roll it away from the house on an unpaved driveway and over a lawn to get it in a safe spot to run it. That is quite a struggle and I'm not getting any younger. I figured there has to be a better way. Searched the font of knowledge and discovered Bob Wilson's well documented inverter system in his 2003 Prius. Decided to give it a try on my 2010 Prius as I too happened to have an inverter (Portawatts 1750). However, I only tested it with a small load...about 300 watts. I just wanted to see for myself what would happen and indeed, the car ran every so often as I tested the power for about an hour to running my laptop, TV, CFL and regular fluorescent lights and other small loads I might want to use during an outage. All worked great! OK, so I had my little power "appetizer" but now I too would like to have heat in a storm as a next step. Using an Amprobe, I determined that the furnace's largest load was when it starts the 1/2 HP blower motor, 10 amps for a few seconds. Then, the load drops off to about 6.5-7 amps for the remainder of the heat cycle. Checked the fusible link in my Prius and it says its 140 Amps...not 100. (I took a pic but as a new poster, the forum won't let me post it.) Tried to find out more info about this on the Internet but have had no luck. My guess is that the 2010 Prius' DC to DC converter can provide more power than the 2003's but I want to be sure. I would need about 1200 watts for a few seconds to start the furnace blower. That would be 100 Amps at 12 volts. This is more than Bob could get during his 2003 heater load test. (Bob: BTW, what does your 1/3 HP furnace motor draw when it starts?) I've also got a 700 watt rated microwave that draws about 9.5 amps for about 1140 watts. It certainly would be nice to be able to use it...when the furnace wasn't on, of course. Again, 1140 is more than Bob could get with his 2003, but IF I have 40% more with the 2010 (1400?), maybe I'm not getting too greedy. I like the idea of only using as much gas as I need and not really having to set the thing up. I mean, I park the Prius 10 feet from the house normally. During Irene, there was no way I could easily set up the portable generator during the storm. The rain was coming down sideways...for hours. The generator and I would have gotten drenched. But if my Prius had an inverter mounted in the back like Bob's, I'm sure I could have found a couple of dry minutes early on in the storm to connect a cord and run it into the house. Juice! As Henry Petroski has pointed out many times in his books, "There is no perfect design". Using the Prius for something it wasn't intended has its limitations and risks. However, putting it to work on an emergency basis for light loads has a lot of appeal to me. I have no plans to sell "the monster" but I'd sure like to use it a lot less...maybe a couple of times a day for 15 minutes or so to take a shower or do the dishes. It would be nice if the rest of the day I could have peace and quiet...and save gas! Anyway, if anyone can shed any light on whether the 2010 Prius indeed can provide more power from the DC to DC converter than the 2003, that would be great. Also, if anyone else has setup their Prius the way Bob has and has any experience with either running a 1/2 HP furnace motor and/or microwave oven with it, I'd like to hear about your experiences. Thanks.