Posted: 9/2/2010 6:13:42 AM EDT
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Question for you all who are better at this than me.
Based on the cost and size of a portable generator for home use, (i.e. power outage) would a power inverter be fine for just keeping the chest freezer and refrigerator cold? Living in a townhouse with a single car garage that is already full with tools and loading bench and supplies so space is already tight and (knock on wood) we haven't lost power for more than an hour since we moved in two years ago. This is just to keep the two cold and save the food until power is restored in a few days. Know if it is good to go, what is a good brand (Black and Decker, Cobra, other)? Size required? TIA |
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You would need a pretty big bank of batteries and a large inverter to run a fridge and freezer. Plus you would need a way to recharge the battery bank. It would be cheaper and easier to buy a Honda or Yamaha inverter generator. I think he is saying that he wants an inverter that he can run off his car parked out front. I was considering the same thing at one time but came up with a small camp generator for $50 instead. |
I really do understand your space limits  I live in an apartment.
Short answer; yes an inverter will work but you will need deep cycle batteries to power the inverter. I looked into thIs a couple years ago––same problem/same limits. I came to the conclusion that after getting an inverter and batteries then I was at the same size and volume as a Honda EU2000i |
| I use a B&D 750 Watt inverter on my truck to power most of my electric tools (hammer drills, grinders, paint sprayers, saws, etc) on the ranch. It has a surge capability of 1500 watts and will run my 110 air conditioner unit without any problem. I haven't tried it for a refrigerator/freezer, but if they are newer units you shouldn't have an issue. |
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Probably a good idea to check local/state ordinances - there are many that prohibit leaving a running vehicle unattended with the keys in it (even if locked). Some have exceptions for cars with remote start. Might also want to check with your association also - I have heard of some that actually prohibit stuff like generators...or they may have a general noise clause that would cover it.
No sense in spinning your wheels until you know what you can and can't do... |
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Thanks all. No issue with running vehicle in driveway here. Both appliances are new within the last two years so they aren't old power hogs. Guess I will just need to check out a 1000W power inverter and hook it up to the truck and check it out. The lists I have seen show the freezer needs 700 watts to run but an additional 1500-2000 watts to start. Time to pull up the specs on what I have and see what it takes.
As for the generator, room could be made but them the issue is location and moving it to run and fuel storage on top of the noise issue. That is why I am looking at the truck as the source. Hard to beat a 30 gallon easily fill able tank. Was just hoping someone had done it and could guide me in the right direction for an inverter or tell me that I am headed for failure. |
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You might what to think about you generator on your truck and if its big enough?
Most small trucks only have 100amp or smaller, a 1500w inverter will pull that. You do not what to burn that up in an emergency. If you what to still just use a inverter you should go to a good battery store and look at there deep cycle batteries. You can buy 2 or 3 hook together; get an idea of the prices. If you are planning on pulling say 50amp hours and you have 300 amp hours of battery, that only 6 hours of run time. Figure out how many you need to run for 12 hours And keep in mind when batteries are charging they put out some very bad fumes!! But a Honda generator is going to less then the batteries, inverter, and the charging system go to http://www.northerntool.com/ |
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Thanks all. No issue with running vehicle in driveway here. Both appliances are new within the last two years so they aren't old power hogs. Guess I will just need to check out a 1000W power inverter and hook it up to the truck and check it out. The lists I have seen show the freezer needs 700 watts to run but an additional 1500-2000 watts to start. Time to pull up the specs on what I have and see what it takes. As for the generator, room could be made but them the issue is location and moving it to run and fuel storage on top of the noise issue. That is why I am looking at the truck as the source. Hard to beat a 30 gallon easily fill able tank. Was just hoping someone had done it and could guide me in the right direction for an inverter or tell me that I am headed for failure. the smaller 2000w generators (honda and others) would serve your purpose perfectly. the hondas are super quiet, relatively light and sip gas - the chinese knockoffs are not as quiet and don't get quite the fuel economy, but are much cheaper. remember, you're not going to be running it all the time if you just want to keep food cool and/or frozen. you'd fire it up for an hour, let the fridge/freezer run and cool down and then shut the genny down. if you were concerned w/ fuel, like you said your vehicle has a large tank, jut always keep it above half a tank. just another alternative. |
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Thanks all. No issue with running vehicle in driveway here. Both appliances are new within the last two years so they aren't old power hogs. Guess I will just need to check out a 1000W power inverter and hook it up to the truck and check it out. The lists I have seen show the freezer needs 700 watts to run but an additional 1500-2000 watts to start. Time to pull up the specs on what I have and see what it takes. As for the generator, room could be made but them the issue is location and moving it to run and fuel storage on top of the noise issue. That is why I am looking at the truck as the source. Hard to beat a 30 gallon easily fill able tank. Was just hoping someone had done it and could guide me in the right direction for an inverter or tell me that I am headed for failure. You need to first get a kill-a-watt meter and find out exactly how much each appliance needs to run. I doubt your freezer needs 700 watts unless it has an auto defrost. Most likely it is around 150 watts or so. My 15 cf chest freezer uses about 100 watts. My 26 cf fridge uses about 120 watts until the defrost kicks in then it is 500 watts. Anyways I ran my fridge for 3 days after a hurricane off an inverter, a vector 1500 watt msw inverter, hooked to my car and it worked but i killed my battery. I didn't know much about inverters or batteries then or I wouldn't have killed the battery. Plus you definitely don't want to burn up the alternator. |
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Thanks trkarl. I'll check into that. Will also research what alternator and battery I have. May just need to switch out the battery for a heavy duty one. The Avalanche "shoud" have a heavy duty alternator.
Small generator is still not out of the question. Just looking at price. The Championn was a 6500W for about $600. Need to price out the Honda and see if it is worth getting the smaller based on size and price. |
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Consider this option:
Solar panel you can set in the window, if you have west, east or south facing windows. Connect these to your batts, then the inverter. Clean, quiet and no exhaust issues. You can hide the batts and inverter in a closet if possible. I agree with the Killawatt though, you need to see what your demands are, before you proceed. |
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Thanks trkarl. I'll check into that. Will also research what alternator and battery I have. May just need to switch out the battery for a heavy duty one. The Avalanche "shoud" have a heavy duty alternator. Small generator is still not out of the question. Just looking at price. The Championn was a 6500W for about $600. Need to price out the Honda and see if it is worth getting the smaller based on size and price. Can you afford to make the noise that a "lawn mower" noise-type generator will make? As I said earlier I've had to do this very same consideration. These are the things that I found out. >You might be able to use the battery in the car to drive the inverter, but a standard car battery is not made for this duty and can very easily be damaged leaving your car disabled. >Better to get a dual purpose deep cycle and stating battery, but a single battery will not have a lot of reserve. Battery $250 inverter $250 = $500 >So we might need a battery bank, but we don't have room to keep the battery bank. Batteries $500 total $750 >So get a generator $300 >But in my place any noticeable generator noise would create a grave security risk during any power outage. Honda EU200i quiet genny $1000 >And the value of the food in the freezer ranges from $0 to $400 >So I would have to have 2 or 3 power outages that are longer than 48 hours to break even on my investment, if I lost $400 of food each time. >We've had two power outages IIRC. >Duration of longest outage = a couple of hours YMMV Because of the costs involved I chose the economical method of freezing water bottles to keep the freezer full of dense thermal mass. I also place the ice at the top of the freezer to keep the food frozen longer in the event of an power interruption. |
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The Avalanche "shoud" have a heavy duty alternator. At engine idle speed, the output of any OEM alternator will be just a small fraction of its maximum rated output. For example, if it's a 130 amp alternator, you might be lucky to get 50 amps out of it at idle - and part of that current will be consumed by the engine's fuel pump, dashboard gauges, ECM, etc. So, you've got two options: 1. Make sure your inverter's continuous current consumption is well below the alternator's idle output current, or 2. Figure out some way of running the engine at much faster than normal idle speed. If you go with option 2, you'll also be dealing with additional fuel consumption - and the fuel consumption of a V8 will be bad enough already... |
<––––-poorly thought plan
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Consider this option: Solar panel you can set in the window, if you have west, east or south facing windows. Connect these to your batts, then the inverter. Clean, quiet and no exhaust issues. i may have missed the news on this –– did solar panel power outputs go up a hundred-fold this week? 
ar-jedi |
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Because of the costs involved I chose the economical method of freezing water bottles to keep the freezer full of dense thermal mass. I also place the ice at the top of the freezer to keep the food frozen longer in the event of an power interruption.
This is the route that I went. Genny is not safe to run in my AO and the alternatives cost way too much. Instead I just got some 1.5 gal water containers from Wallyworld, filled 'em up and froze 'em, leave them in the freezer and fridges (2). If we know something's coming we fill up all remaining space in the freezers with water bottles. Put some thermometers in the freezers and fridge and monitor temps, too. Not a perfect solution, but very cheap and will keep food fine for anything but an extended outage, in which case I'd rather have a big BBQ than spend tons of cash or precious, precious fuel on trying to save a couple hundred dollars worth of food. It also gives us some cold water to drink after they melt, along with some more water containers. Fuel in a grid-down situation (especially post-hurricane) is priceless. Worth far more than the my cold food. I've got canned/dry goods to get me through for quite a long while after it's gone. Once the fuel is gone, though, it's gone. |
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Power will be restored in a few days? Most of the time yes Oh, really?  Rly!
Get some BBQ fuel and eat well.  Keep the freezer full and properly packed and not worry
As I said in my post before I would need an outage of more than 3 days before the mere risk of loosing food that may only be worth one third of the value of a generator is a threat. Given the costs involved then I am financially ahead to stock the freezer properly As always YMMV |
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Consider this option: Solar panel you can set in the window, if you have west, east or south facing windows. Connect these to your batts, then the inverter. Clean, quiet and no exhaust issues. i may have missed the news on this –– did solar panel power outputs go up a hundred-fold this week?
ar-jedi Not that I noticed, they are still around 200 watts a piece for the most modern ones... I may have missed the point of your comment though. Say 1x 200 watt solar panel + say 10hrs of decent light on it at even 70% efficiency = 1.4KWh figure 10% transmission loss you still have 1.26KWh If that is hooked up to a pair of golf cart batteries together, (225ah at 12v right? Guesstimate) that should give a total potential output of the batts at 2.7KWh. If you kept it to half discharge on the batts, you would have 1.35 Kwh which is pretty close to have the single solar panel could charge in a day based on the conditions above. Now for the useage, my chest freezer uses 150 watts while its on, and if he ran it for an hour solid twice a day (or a better idea, half an hour four times a day), that is only .30KWh per day. Figure a fridge which is less efficient would use twice that, so you have just shy of 1 KWh useage per day on the system, so why wouldn't it work? I don' t think it would run anywhere near what it needs to through a window, but if he had it mounted somewhere a bit better, where is the problem? I wouldn't be suprised if there is something wrong with my math, or some variable that I didn't account for, I am by no means a subject matter expert, but it seems like it makes sense to me... Not any cheaper than buying a small honda, but it is theoretically more sustainable over long term... ETA: I just noticed your emphasis was on the through the window part... I think it is still a viable idea, but with a slightly much better location for the panel. ETAA: On running your truck, the alternator on it probably produces much less than 50% of its capacity at idle, probably closer to a third and remember, your truck is using some of that electricity to keep itself running... |
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Thanks all.
I do keep the freezer full. Like it has been said the power would have to be out for a couple of days and (knock on wood) we have only lost power for an hour or two in this area in the past 5 years. Eventually, time, place and $$$ - I will get a generator. At least when I property I can run it out to use and build the deer stand with power tools. |
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Thanks all. I do keep the freezer full. Like it has been said the power would have to be out for a couple of days and (knock on wood) we have only lost power for an hour or two in this area in the past 5 years. Eventually, time, place and $$$ - I will get a generator. At least when I property I can run it out to use and build the deer stand with power tools. Keep an eye out on craigslist, I got a like new Generac 4000exl for a third of what it cost new, still had the sticker on the exhaust. You can get great deals if you are patient... |
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<snip> 10hrs of decent light on it at even 70% efficiency = 1.4KWh figure 10% transmission loss you still have 1.26KWh <snip> No. Sticking a solar panel behind one or two panes of glass probably means you won't get any decent light and, due to the geometry involved, you surely won't get 10 hours worth of useful light. Your power production estimate is way too high. |
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<snip> 10hrs of decent light on it at even 70% efficiency = 1.4KWh figure 10% transmission loss you still have 1.26KWh <snip> No. Sticking a solar panel behind one or two panes of glass probably means you won't get any decent light and, due to the geometry involved, you surely won't get 10 hours worth of useful light. Your power production estimate is way too high. keep reading... all that is based on it being in a better location |
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<snip> 10hrs of decent light on it at even 70% efficiency = 1.4KWh figure 10% transmission loss you still have 1.26KWh <snip> No. Sticking a solar panel behind one or two panes of glass probably means you won't get any decent light and, due to the geometry involved, you surely won't get 10 hours worth of useful light. Your power production estimate is way too high. keep reading... all that is based on it being in a better location You're right, it was someone else who suggested putting it behind a window. Sorry. However, I sitll maintain that ten hours of light per day is optimistic. The map here indicates the full-sun-equivalent hours of sunlight available throughout the country. Highest area is 6 full-sun-equivalent hours per day, but that only applies to a very small geographic area.The majority of the country gets 4.5 hours or less of full-sun-equivalent per day. |
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<snip> 10hrs of decent light on it at even 70% efficiency = 1.4KWh figure 10% transmission loss you still have 1.26KWh <snip> No. Sticking a solar panel behind one or two panes of glass probably means you won't get any decent light and, due to the geometry involved, you surely won't get 10 hours worth of useful light. Your power production estimate is way too high. keep reading... all that is based on it being in a better location You're right, it was someone else who suggested putting it behind a window. Sorry. However, I sitll maintain that ten hours of light per day is optimistic. The map here indicates the full-sun-equivalent hours of sunlight available throughout the country. Highest area is 6 full-sun-equivalent hours per day, but that only applies to a very small geographic area.The majority of the country gets 4.5 hours or less of full-sun-equivalent per day. Now that there is something I didn't know. So when the sun is up for 15 hours a day it in the summer, only 5 of those hours actually count? What about the other 10 hours? I figure the last two and the first two hours of the day might not count due to the low angle of the sun, but anything after that I would think that the pv panel is still grabbing light, maybe not full capacity, but some, which is why I figured the 70% efficiency over the 10 hours... Might have to do some investigative reporting on this one via the smart meter on the neighbors house... Please school me on what I am missing as this might affect the plans I have for my small solar set up and how much capacity I need... ETA: I get it now I think. From the linked site: a good rule of thumb is to simply multiply the peak watts (as stated on the solar panels UL Listing) by the above DNI values for your area. This calculation will provide a conservative estimate of the average net daily production of a solar panel. Indirect insolation and high angle insolation (early morning and late afternoon) is disregarded in this simple calculation so as to offset average power losses due to wiring resistance, battery or inverter loss etc.
So, 200w x 5hrs a day (my AO) 1KWh based on that formula. Still enough to make the overall equation work since our estimated use was 0.90 KW. Kick that up to 220W panel and you are back to having a decent margin to work with... All in all, I wasn't too far off; about 20% too optimistic with something I just sort of worked up in my head... |