Florida and Power Outages

Are you trying to use a single 12 Volt car battery?

Typically you get about 100 amp/hrs out of a single battery. The inverter is 90% and needs 470 amp/hrs at full capacity.

This site may be helpful:

Deep Discharge Batteries

No battery is in the engine compartment and is being recharged by the automobile engine as the recharge source.

Does the automobile charging system have the UHUMP to support the necessary recharge?

--Duxk

if you look at the cars handbook it may tell you what the alt output is.

I would gues around 50 amps

you might like to add additional batteries by way of jumper cables so there is additional capacity.

You need the make/model of the car's alternator and then lookup what its capacity is.

Probably a woefully inefficient system and I would be hesitant to waste gas that I might need for emergency travel or immobilize the vehicle if it breaks down due to heat stress. Hurricanes here in Florida usually occur during the hottest months. That is one reason I have an in-ground pool and chlorine.

Cars are not designed to idle for long periods. They need forced air cooling and idling does not produce much in the way of alternator power anyway, so you may be fighting a loosing battle.

The best choice is a portable generator. They use less gas and are not as expensive to fix as a car engine that blows a head gasket or worse.

If your well heeled, a solar system will help bare some of the daily load.

From my perspective, we generally loose only a few days to two weeks of power. Unimaginable how people survived down here 100+ years ago (before electricity, too), but they did! Refrigeration for food is probably the most important thing after potable water. Fortunately, we have an artesian well that could be purified in a pinch and there is always a few days warning where you can start filling bottles in advance.

I agree with a nony mouse ero.

I gave you a GA! I have heard of people using a Toyota Prius to power their gas furnace, refrigerator and 1 lamp during power outages for up to three days. I don't think I would try powering the entire house with it and I am not sure how much gas was used.

Note: it may have just been a small electric heater that was used instead of a furnace.

The furnace most likely uses less power than a small electric heater.

Actually, the inverter's efficiency is 90% at load, so the full current draw is more like 470 Amps at 12 Volts, which is way out of the league of the average automotive alternator.

Be careful here, the cars engine is probably only 30% efficient for one thing, at Wikipedia they state:-

Most steel engines have a thermodynamic limit of 37%. Even when aided with turbochargers and stock efficiency aids, most engines retain an average efficiency of about 18%-20%.

Which is appalling.

Lead acid batteries on a good day, in perfect condition are at best 70% efficient......if you charge them fully, the efficiency drops even further, so stay with a big battery and only charge to 70% capacity.....

So the losses quickly mount up.......

I think we are on the same page. It does not seem to be a good use of the machinery.

These links may help

http://www.google.co.uk/search?q=car+alternator+output+amps&sourceid=ie7&rls=com.microsoft:en-gb:IE-SearchBox&ie=&oe=&rlz=1I7DKUK_en-GB&redir_esc=&ei=W-_ySwjM_fwGsa20_Qw

http://www.termpro.com/articles/electsys.html

http://en.wikipedia.org/wiki/Alternator

http://www.bcae1.com/charging.htm

In fact i would say 2 generators one for lighting one for the power circuits.

then if one fails you have a back up.

solar panels to suppliment generators to keep the batteries topped up before and after the outage.

since the alternators are typically under 75 amps at just over 12 volts, you'd be luck to run 1000 watts.

Unless you are using a pre 80s alternator, or some small foreign compact, alternators are likely to be at 100 amps or greater. The trouble is that the current alternators have become smaller, and less able to run at full current for long periods.

I have run my refrigerator, TV, and a single light bulb from an inverter powered by a car battery overnight, and recharged the battery in the morning, and again just before dark. I could keep this up for over a week during Wilma, Katrina, Edwardo(?)

If you need, you could use LEDs and get by. When the heat, or rain comes though, it will be hellish.

Has anyone used a UPS for backup power during power outages? Comments?

You might be lucky and get away with this for a while, but car batteries are not designed to be run down low without damage to the cells. Deep cycle batteries are.

GA

If you check, the original poster did not want to run these off of batteries, but a running alternator. The battery will never discharge.

Check the original poster all you want - that should not be done so people are telling what can be done..

There are just some people that will always look for a cheaper way out, or have other reasons to resist generators.

I absolutely agree that a generator is the correct thing for standby power. Living in multi floor condominiums makes generators illegal, and likely to be stolen. Most of the Honda powered generators are quiet enough to sleep through, but most others become so noisy that some quiet is welcome.

And telling someone to purchase another battery for one's car or truck is well received, as the money is not wasted if there is no power outage. At least the owner will get another year out of the vehicle without battery failure. If the battery can survive running low and recovering a few times, you will usually get power back y then, or will be in the middle of a massive power outage, and need to buy the generator.

The battery- inverter plan is no replacement for a proper pre-wired, automatic standby generator. But it does not tie up over $3,000 either.

I've been giving some good answers around and I feel good about it.

Get 7 to 10 cars that are not running hot and that is the power you will need.

Lots of gas to pay, no?

I have been thinking of putting one of the Harbor Freight 10kVA generators under my hood, but the pulley work here i a disaster and I am already tired of thinking about it. And not enough space under the hood too.

Have been 3 months without power after Jeanne.

Life is beautiful in the hurricane belt.

If you need short-term power, and can't afford a gen-set, get a small inverter, 200-400 watts. This will run most little things you might "need" while the grid is out. 5000 watts is excessive for most applications. If you need 5kVA, you need a good charging system behind it or a good battery bank to last through a potential power outage. An emergency generator would be cheaper than the required battery bank.

If you have a hybrid you can use it for emergency power with a fairly simple modification that costs a few hundred dollars.

I would suggest a trip to Lowes...

Find a solar blog such as www.wind-sun.com/ForumVB and learn about batteries. A car battery is not suitable - deep cycle batteries are needed. A small generator is a far better solution - but then şf not needed what to do? That is the reason they are called 'emergency' generators. To me this is not a good thing to take a shortcut on.

Theoretically there are some good large truck alternators around (24 volts usually) that one might be able to "add in" to a car's engine bay, maybe easily removable, for such days.......

Maybe you can find one that makes 110 volts at 60 Hz, with the right pulleys and a way of keeping the car revs constant, you might just get there......

A purpose built generator would be better though, for short term usage petrol, for long term diesel is best.....

For long term storage, the propane or natural gas models have some advantages also. Propane and NG store well and are ready for use when needed.

Do you actually need 5kw? I would first do a critical analysis of everything necessary, find the lowest devices that provide that and build your system from there.

Examples: pick up a small window AC to cool one room, probably a bedroom. Get LED or CF lighting. This leaves refrigeration. You can calculate what your frig needs and make that your major device, or consider just cleaning it out and putting a few perishables in a smaller apartment frig or just an extreme cooler. (peltier coolers are small, but not as efficient as compressors). You can also consider getting a propane frig and a couple tanks.

If possible, get 12 volt DC devices to replace 110v ones. You can find LED or CF lights and fans at boating or RV shops. Occasional charging of a battery might be more efficient than constantly running a gennie.

For cooking, use your camping gear. (You DO have camping gear, right?) If nothing else, get one of those $20 butane burners.

Stop trying to piecemeal this, just go have a Natural gas powered 18-22KW Standby generator professionally installed and be done with it. If sized appropriately, you'll even be able to run your AC and keep from sweating yourself to death. this will also help with issues of fuel availability. After Hurricane Ike, we had at least three or four days in which none of the gas stations in the area had power and gasoline for generators was getting very hard to come by. A natural gas generator would have saved me several hours a day scrounging for gasoline.

In a pinch (and this is ONLY in a pinch) IF you have a circuit breaker panel that has a mains disconnect or main breaker that disconnects the panel from the power line, AND you have a 240V 3 phase electric dryer hookup, then you can use a large (say 6500w or larger which will set you back around $500-$600 if you buy it BEFORE a hurricane forms.) 240V 3 phase generator to power your entire house but YOU MUST TAKE PRECAUTIONS!. What I am about to describe is going to violate NEC code and can be dangerous to both you, your neighbors, and any power line workers that may attempt to repair your electrical service if you fail to take all necessary precautions. This should only be done in an emergency, if at all. Doing this is ENTIRELY AT YOUR OWN RISK.

Step one: AND THIS IS THE MOST IMPORTANT OF THEM ALL! Disconnect the house from the power line by tripping the main breaker or main disconnect. Once you have done this, nothing you do can injure any bystanders or power line workers who may be near or working on any downed power lines. If you do not have the means to safely disconnect the house from the power line, STOP RIGHT HERE. GO NO FURTHER!

Step two: manufacture a 4 wire male by male cable that will reach from the generator that is located at least 10 feet away from the house (to prevent exhaust gasses from getting sucked into the soffit vents and/or windows and killing the occupants. Several families died after Hurricane Ike hit Houston when they were overcome by CO from generators or gas lanterns/stoves.) to the dryer plug. most of these plugs are the twist-lock type which is good because the pins of the cable will be live when the generator is running. under no circumstances should you touch the pins if it becomes disconnected while the generator is running.

Step three plug the cable into both the dryer plug and the generator.

step four trip the main breaker on the generator in order to unload the generator during the start/warm up sequence.

step five ensure all prior steps have been taken, check them again, then check them one more time to be sure.

step six check them one more time.

step seven start the generator

step eight. close the breaker on the generator after the generator has reached running temp and stabilized.

reverse the procedure to disconnect.

This is known as a suicide cable, and there is a reason why it is called that. If you don't know what you are doing you can hurt yourself and others. But if you have someone in your household who absolutely must have power for things like oxygen generators or other medical equipment, or even to run a small window type AC unit assuming the generator is sized large enough to do that and the wiring/breaker that is connected to the dryer connection is heavy enough to handle the current being drawn. This is by my way of thinking, a safer alternative to having a nest of extension cords stretching all over the house for people to trip over or to overload and cause a fire. At least you know that the wiring in the walls is protected by breakers and can't be tripped over or overloaded.

Why not get him to buy and install a crossover switch on his incoming power connection, either the power comes from the mains or from a Genny- and never the twain shall meet......everyone is helped.

That takes away a lot of the danger, not all, but a lot!!!

The switch is a lot cheaper than anyone dying.....

A crossover switch counts as a mains disconnect so I figured I covered that. but it probably could stand to be pointed out as well.

I would also add that the installation of an automatic transfer switch changes how the generator is connected to the building so the above instructions would have to be adapted to that situation. you could no longer use the AC Dryer connection as your feed point. you would need a dedicated feed point connected to one side of the ATS.

I would not have an automatic crossover switch under ANY circumstances, only one where you go and switch it over by hand each time, even cheaper.....

Then no need for a "suicide" cable of the type you mentioned, just a normal cable coming FROM the crossover, TO the genny outlet socket.......

Lots of GA's but had to give it to peterg. The bottom line. Forget using your car. Just get a Honda or whatever 220VAC with appropriate capacity generator and get it properly connected to your abode with transfer switch by a qualified electrician. Done.

Agreed, thats what was posted earlier as well....