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With the probably approach of Hurricane Florence, I must decide what to do should we lose power for an extended period of time. One option is to run an inverter off of our cars, which would mean running the engine at idle for an extended period of time. I have no doubt that this is a bad idea, but how bad is it really? Would it be ok to do it for a couple of days if I get the oil changed afterward? Looking for informed opinions.
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With the probably approach of Hurricane Florence, I must decide what to do should we lose power for an extended period of time. One option is to run an inverter off of our cars, which would mean running the engine at idle for an extended period of time. I have no doubt that this is a bad idea, but how bad is it really? Would it be ok to do it for a couple of days if I get the oil changed afterward? Looking for informed opinions.

 

What are you trying to power? What are your basic emergency needs?

 

Running a car for days at a time isn't usually the best idea. It's also not built to convert fuel to electricity.

CO poisoning is a big risk running the car or a generator.

 

If you are trying to keep perishables cold, I'd try to find some large coolers and fill them up with some ice. If you do loose power, you can move stuff out of the refrigerator into the coolers. Most good ones hold for a couple of days and even after all the ice melts, the cold water keeps things good for at least a day.

 

If you have a grill, grab an extra propane tank, if you don't have a grill, see if you can get some camping style ones to get you going for small things. Get some of those astronaut food packs; clean and fill up your bath tubs so you have fresh water.

 

Keep the gas tank full for if/when you need to go 50 miles to get basic stuff, re-fill ice in the coolers and charge portables while you drive.

 

When Sandy hit NJ a few years ago. Everyone had a generator from the year before. And in a couple of days, the entire area was out of gas. The pumps that had gas didn't have electricity and the ones that had electricity didn't have gas! Soon folks were lining up 2-3 blocks waiting for hours in the cold with cans to get gas.

 

Be a minimalist and wise. That's the key!

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I've read that most cars average 1/5 to 1/7 of a gallon of gas per hour of idling which on a full tank would get you over 3 days worth of power on a tank of gas. I think the biggest strain would be on the alternator as I am not sure how much power you actually would be able to get from your car by doing this. If you change your oil after, you engine components should be fine since once your car is warmed up it shouldn't need to burn rich during a warm up period.

 

Is it a great idea - I don't think so. But if you have to do it and there is no other alternative, then I don't think hurt the longevity of your car other than your alternator may die on you early than expected down the road. I think the biggest issue would be not generating enough power depending on what you need to run.

 

In cold climates, people often leave their cars running 24/7 as it's cheaper for gas than it is to try and get it started after sitting in frigid temperatures all day.

 

Also, as someone else mentioned, you'd have to keep it outside as you do not want toxic gases and carbon monoxide to get into your house from the exhaust if you were to leave it in your garage.

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I was without power after a storm for 6 days earlier this year. I used the inverter I installed in my Jeep to power things in my house on and off for almost a week. We have a tankless water heater so I used that to power the board to take hot showers. Used the inverter to run the fridge on and off. You don’t have to run the fridge continuously if you are not opening the door often. Get 5-6 (or more if you can fit them) gallons of water and freeze them. When you lose power, leave a few in your freezer and place a few in your fridge. This will help maintain a cold temp longer. The initial power draw on start up of fridge or any electric motor may overwhelm and fry a cheaper inverter so be aware of this. The initial draw is not the same as when it is running, it is much higher.

 

At the very least, I recommend freezing water as much water you can fit and using this to help keep the fridge and freezer cold. And in worse case, you will have some fresh water if you don’t have running water for an extended period of time. Every bit helps

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The biggest thing we'd want to power would be the fridge. Other than that, probably cell phone chargers, maybe a light or two. We have a tankless hot water heater as well, but, honestly the "cold" water this time of year is warm enough to make it unnecessary.

 

Looks like the inverter I have is not big enough to run my fridge though. It can do 140W continuous and 400W peak, so I'd have to find a better one if I wanted to keep the fridge running.

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The biggest thing we'd want to power would be the fridge. Other than that, probably cell phone chargers, maybe a light or two. We have a tankless hot water heater as well, but, honestly the "cold" water this time of year is warm enough to make it unnecessary.

 

Looks like the inverter I have is not big enough to run my fridge though. It can do 140W continuous and 400W peak, so I'd have to find a better one if I wanted to keep the fridge running.

 

I always found using a couple of large coolers with ice to be the most efficient than running the fridge. There is nothing that can fail. And its much easier to get out to a spot farther out that is not impacted and pickup ice bags.

A few pounds of burger patties, milk, cheese and yogurt was all I typically stock in the coolers and a variety of fresh veggies. Each family's needs vary.

 

Good luck and be safe!

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I always found using a couple of large coolers with ice to be the most efficient than running the fridge. There is nothing that can fail. And its much easier to get out to a spot farther out that is not impacted and pickup ice bags.

A few pounds of burger patties, milk, cheese and yogurt was all I typically stock in the coolers and a variety of fresh veggies. Each family's needs vary.

 

Good luck and be safe!

 

Thanks. I have some coolers, and I am bagging ice from the ice maker as fast as it will make it. Hopefully power won't be out that long if at all, but I've been through enough hurricanes and ice storms to know it can be days or even weeks, depending on how hard we get hit.

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you are better off buying a generator. I do not recommend idling the car engine as a source of 12V power to an inverter.

The output on the alternator, especially at idle, isn't much, and extended run time at idle may kill the alternator, not to mention, it would be bad for your engine.

extended periods of idling for an engine are not good.

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Where are you located? Where will the car be in relation to the house/apartment?

 

A few things:

 

1. Idling your car engine for days is perfectly fine. We're not talking about a normal practice, but something done in a time of emergency. This additional week of nearly-constant running will have a negligible affect on your engine life.

 

Just check the oil and coolant levels to ensure you're good to go. You don't want to burn oil and not catch it. If you the oil level rises, then it's very likely due to fuel dilution; in which case, simply change the oil after all is said and done and you'll be good to go.

 

2. Alternator: Running lights and chargers from an inverter via your alternator will not be much of an issue. I don't know what your actual output limit will be (not based on some output graph), but I can't imagine that you won't be able to keep the lights on and chargers going, so long as you've got LED lights inside, not incandescent.

 

3. Forget about your fridge - use up what you can; put as much as you can in the cooler, and consider the rest gone, should you be directly in the path of Florence.

 

If I were in NC right now and didn't have a generator or large stock pile of food and water, I'd be driving as many hours as it took to ensure I at least had the latter, if I wasn't able to get a genny

 

4. Generator: If you can't forget about your fridge and if you can find a small genny, don't worry about storage. Even if you're in an apartment, you can likely run it out of fuel and drain the oil (if you wanted to) and keep it indoors perfectly safely.

 

More importantly, I'd ensure that you have adequate ventilation. If you have to run an extension cord from the generator outside to the fridge inside, make sure the generator is far enough away and not in a position to have its exhaust directed into the house/apartment.

 

5. Safety: While you're out looking for non-perishables, you should also be stocking up on batteries, battery-powered lights, battery packs, crank/solar radio, etc. I have many lanterns and many flashlights in my house. When we lose power for a short period of time, I don't even consider running the generator right away, so long as I had the foresight to turn the fridge and freezer to their lowest setting WELL in advance, to buy me time.

 

If ANYONE here doesn't have an emergency kit that includes at least one lantern and one flashlight, as well as other common-sense things like a first-aid kit, cold-weather gear, etc., I'd recommend you get on that. You can buy the cheapest LED lights for dollars, and they'll be powered by common AA or AAA batteries, which you should also have stock pile of. I don't personally have stock pile of alkaline batteries, but I've got over a dozen NiMH rechargeables that I keep charged and ready to go. I usually scavenge rechargeables from my kid's toys and charge them up if we've got a storm coming, too.

'15 FB25

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RSB, Fr. Strut Bar, Tint, STI BBS, LED er'where

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We're in Durham, NC. Looks like maybe we'll miss the worst of the storm based on the latest forecast (fingers-crossed).

 

If we do lose power, we've got enough batteries to run LED flashlights for about a week or so. I've got plenty of ice bagged for use in coolers for perishables currently in the fridge. I expect the items in the freezer to be a loss.

 

Turns out our neighbor across the street has a whole-home generator and offered to let us stay with her if we have an extended outage, so I think we'll be fine in the big scheme of things.

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Good luck, dude! If worse comes to worst, make sure you keep us updated. I'm sure there's someone on this forum in the area, but out of harms way, who would be willing to help out!

 

You can borrow my genny and other supplies, if you can make it up to New England!

'15 FB25

Magnatec 0W-20 + FU filter (70,517 miles)

RSB, Fr. Strut Bar, Tint, STI BBS, LED er'where

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... running the engine at idle for an extended period of time .... I have no doubt that this is a bad idea, but how bad is it really?

Let's put some numbers to it. Without regard to whether it would be good for the vehicle, you won't get much out of the alternator at idle anyway. Here is the alternator output rating published in the Legacy/Outback Factory Service Manual:

 

1,500 rpm => 50 amps [~700 watts]

2,500 rpm => 111 amps [~1,550 watts]

5,000 rpm => 133 amps [~1,862 watts]

 

Extrapolating, you could expect less than 25 amps (~350 watts) at idle ... minus the current consumed by the car itself.

"If you don't know where you're going, any road will take you there." ~ The Cheshire Cat (Alice in Wonderland)

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Without regard to whether it would be good for the vehicle, you won't get much out of the alternator at idle anyway. Here is the alternator output rating published in the Legacy/Outback Factory Service Manual:

 

1,500 rpm => 50 amps [~700 watts]

2,500 rpm => 111 amps [~1,550 watts]

5,000 rpm => 133 amps [~1,862 watts]

 

Extrapolating, you could expect less than 25 amps (~350 watts) at idle ... minus the current consumed by the car itself.

 

Good point. Your Legacy won't raise engine speed to compensate for a higher load than idle speed can provide.

 

What I don't have any experience with: what will happen when the battery dies for a load that is drawn that exceeds what the alternator can put out?

 

Would the engine stall or would the output voltage simply drop to compensate for the increased amp draw and cause the inverter to shut-down on over-current, under-voltage or over-temp? My guess is the latter and the engine will keep going on.

'15 FB25

Magnatec 0W-20 + FU filter (70,517 miles)

RSB, Fr. Strut Bar, Tint, STI BBS, LED er'where

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... what will happen when the battery dies for a load that is drawn that exceeds what the alternator can put out?

The battery will supply power for short-term peak loads in excess of what the alternator can supply, but there won't be enough alternator output at idle to recharge it. It wouldn't hurt the engine, but eventually the battery would be depleted.

"If you don't know where you're going, any road will take you there." ~ The Cheshire Cat (Alice in Wonderland)

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The battery will supply power for short-term peak loads in excess of what the alternator can supply, but there won't be enough alternator output at idle to recharge it. It wouldn't hurt the engine, but eventually the battery would be depleted.

 

That's the crux of my question: what happens WHEN THE BATTERY DIES?

'15 FB25

Magnatec 0W-20 + FU filter (70,517 miles)

RSB, Fr. Strut Bar, Tint, STI BBS, LED er'where

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what happens WHEN THE BATTERY DIES?

The alternator won't be able to support the full load, and the system voltage will drop as the battery discharges. The system voltage may even sag so low that the engine eventually quits, or it may converge on some low but sustainable voltage. Feel free to conduct the experiment yourself.

"If you don't know where you're going, any road will take you there." ~ The Cheshire Cat (Alice in Wonderland)

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Funny, this is what I had stated previously - that the alternator doesn't have much output at idle.

 

As for what happens to a running engine when the alternator and/or battery dies:

when the alternator dies, the electronics on the engine, including the ignition system, will run for a period of time on the battery, until the battery voltage drops below the range of what those electronics can handle.

Besides the idiot lights on the dash, the engine will start to cut out due to lack of good spark from the plugs (low ignition voltage), and will hiccup, especially under acceleration.

From loss of the alternator, to stuck on the side of the road, could be anywhere from 10-15 minutes to maybe 30-40 minutes, maaaaybe. It would depend on a bunch of factors, like size of the battery, make and model of the car, size of the engine (and # of plugs/ignition system, etc)

This happened to me in a 2002 Ford Explorer V6 once. I made it about 20 minutes before barely making it into the parking lot that I needed to get to.

 

As for what happens when the battery dies:

- it really depends on what you mean by "dies". There are several things that could happen.

All assuming the alternator is working properly:

1) a "dead" battery may accept a "surface charge" meaning that when charging it, it reads a normal 13-14V, but the moment you remove the charge, OR put even a small load on it, it tanks to under 12V or less.

If the car was running, the alternator should be able to maintain the engine running and supply the power needed to drive (short term).

Once you shut off the car, it wouldn't restart.

This is what you may typically see when jumpstarting a car with a dead battery - keep it running until you can replace the battery

This is the most common "battery fail"

Once you remove the charge (either turn the engine off or remove the battery charger) the voltage will slowly drop.

Or if you try to restart the engine, it wont.

Or if you turn on the headlights, the voltage will quickly drop from 13 to 12 to 11...

 

2) a dead battery that had an internal failure:

this would typically produce 0 or close to 0 volts, and I would not recommend trying to run the engine with this, as it could damage the alternator, blow a main fuse and possibly cause the battery to explode. Not likely to happen, but possible.

This scenario is not a common.

 

Again, for the cost of a replacement alternator and/or battery, one could buy a generator at Harbor Freight, use it then sell it (if they don't have room to keep it) and still be ahead of the game.

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