Small inverter

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dabrooks

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I have a 2001 Georgie Boy Landau. It does not have an inverter. It has one 12 volt house battery. I wanted to add an inverter just to power a 19 inch flat screen tv and a dvd player. What size inverter do I need and can I install it right up in the cabinet where the tv and dvd player are mounted. I see several smaller inverters on-line that look like they have 110 receptables on the end which I could plug the tv and dvd player into.
 

Great Horned Owl

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You can do it that way, but it is far from ideal. Remember, that the 12 volt input current will be 10X greater than the 120 volt output current. Unless you run really huge wires, you want to install the inverter as close to the battery as practical. The wire run from the inverter to the TV is of much less concern.

Joel
 

Alfa38User

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Only one 12V battery??? If you do any boondocking at all where you require that small inverter, the lights and perhaps the furnace on occasion, you will not last out the night. Furnaces are very 12V hungry beasts..... I suggest you look into adding a bigger battery bank at least.
 

dabrooks

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That is the info I was looking for. It is easy to install it close to the battery and run 120 to the tv. Do you know what size I need ?
 

dabrooks

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I have a generator for boondocking. I was only looking to run the tv and dvd player while traveling so the grandkids can watch movies while we are driving.
 

Foto-n-T

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Technically speaking you could probably use a 175watt inverter like one that plugs into a cigarrette lighter but it probably wouldn't last long.  Modern TV's etc. actually draw very little power, my entire entertainment system, TV, Satellite and sound system only draws 150 watts.  That doesn't sound like much but in reality it's over 10 amps of draw on the battery(s).

I would recommend an inverter of at least 1,000 watts.  You want to keep in mind that if you get a small inverter that will just power the two appliances that you want to run it's going to be running at pretty near max performance all the time.  This condition equals heat and heat is not your friend with inverters.  A 1k inverter to run what you're planning on will be performing at less than 25% of it's max capacity.

As Alfa38User stated, you're probably going to find out that your battery is going to be the weak link in this whole scenerio.  That doesn't mean don't do it, it simply means that you're going to have to find out by using it what your requirements for battery(s) really are.  I think that you're going to find that once you install an inverter for just those two items that there will be other uses for it as well.

Remember:  DC doesn't travel well, heavy gauge stranded wire and short distance is best and get a fuse in the positive leading to the inverter as close to the battery(s) as possible, if the positive cable vibrates loose out of the inverter and touches anything grounded it will make a great arc welder.
 

Alfa38User

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Most small inverters inverters at 900 watts will likely be up to the task. Test first though as most are MSW (modified sine wave) outputs and some electronics don't like that much. The TV etc will draw what they need and not the whole 900 watts necessarily. Keep in mind that the published outputs of all these inverters are often the peak numbers and not the continuous working outputs. The TV and DVD units usually have the power requirements printed on their respective labels.

Just a small note that you may be already aware of, make sure the TV in question is out of view of the driver (a federal law requirement). You don't need a visit from law enforcement and the accompanying ticket.... Very often those TV mounted above the windshield will not even turn on while underway.

My Grandkids all have those little DVD players that hang on the back of the seat in front and plug into 12V.
 

Gary RV_Wizard

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I would probably go even smaller than the suggestions above, maybe only 600 watts. The TV + DVD won't be over 200 watts, but I'll bet you end up with some other things as well, e.g. computer, cell phone charger, etc.

Place the inverter close to the batteries if possible, but it should be in a ventilated area (they get warm) and preferable not real close to the corrosive gases that a flooded cell battery may release. But if the batteries are a sealed type, e.g. AGM, then gases are not a concern.

You definitely need more battery to use an inverter.  200 watts @ 12v takes a steady 17 amps from the battery bank, so 4 hours of tv & dvd is 4 x 17 = 68 amp-hours. That's just about the entire capacity of a Group 24 size battery (around 85 amp-hours) and you really don't want to use more than 50% or so of the available AH if you want the battery to last more than a year.

Two Group 27 size deep cycle batteries would give you about 210 AH of battery power, or about 105-110 AH at the 50% level.
 

dabrooks

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Gary everything you said makes sense. If I only use the inverter while driving would I still need a second battery. Another option was a 12 volt tv dvd combo. I see them on Amazon they are not too expensive. The area in the back bedroom is where I would mount it. That is only 10 to 12 ft from the 12 volt distribution panel.
 

John From Detroit

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For Radio and Television use TRUE SINE inverters are best.. MSW's tend to cause interference.

About the smallest TRUE SINE inverter you can get is 300 watts.

That's more than big enough.

DO NOT worry if the inveter is larger than needed (So long as you do't get riduculus) as the inverter only draws enough power to do what it is being ask to do plus overhead,, Overhead is more or less fixed and between a 100 and 500 watt inverter won't be much different,, Efficiency is around 90% peak.. So to figure out 12 volt draw (in amps) divide watts on the TV by 10 (Easy math, and very nearly accurate) you should be within 10 percent (on the safe side).

The point of all that is to say the 300 watt inverter won't run the batteries down any faster than a 175 MSW would.
 

Alfa38User

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You could also use that generator you spoke of while going down the road, if it is a 'built-in'... a bit of overkill but doable. FWIW
 

Lou Schneider

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If I only use the inverter while driving would I still need a second battery.

No - the engine's alternator will easily keep up with whatever current the inverter is drawing from the batteries.

Connecting directly to the rear mounted 12 volt distribution panel will work, but if there's significant distance between that panel and the batteries, it would be better to put the inverter closer to the batteries.
 

dabrooks

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Lou I am sorry I confused you by throwing the 12 volt tv / dvd player in the mix. If I go with an inverter I will be sure to install the inverter close to the battery and then run 110 to the tv.  Thanks for the input on the alternator keeping up with a small inverter. I mentioned the 12 volt panel in refrence to installing a 12 volt tv/ dvd player instead of an inverter. It is only a short run from the panel to the tv cabinet. I was wondering if anyone had any experience with 12 volt tv/dvd systems.
 

Gary RV_Wizard

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As Lou said, the alternator can easily keep up with the 200 or so watts you will need for tv and dvd. But so can your generator, which you already own. At that tiny power load, your generator probably consumes around 0.3 gallons/hr of gasoline, so fuel cost is insignificant.  The generator fuel is probably a tad more than the extra fuel the engine burns to power the alternator and inverter, but we are down to  very small numbers in any case
 

nvrver

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I have a small inverter 300 or 400 watt and it plugs into the 12v plug by the cable/ant plug.  Works fine with my 26" Visio and separate DVD/VCR player.  For what you want it should work for you while traveling.  I can go out to the MH and give you the info on it, let me know.  Regards, Dick
 

dabrooks

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Dick, That sounds like what I am looking for. If you could look I would appreciate it.
Thanks, Dave
 

Gary RV_Wizard

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You can't get 300-400 watts from that plug - probably nothing over 120 watts, if that. May well be sufficient, though.

Does your antenna booster (amplifier) switch  plate have a 12v outlet in it (cigarette lighter plug)?  Many do, though it is not intended to be a high-amperage power source and depends on what the RV maker wired it to.
Looks like this:
http://www.amazon.com/Winegard-RV-7042-White-Plate-Supply/dp/B000GGL4CG/ref=sr_1_2?ie=UTF8&qid=1351607690&sr=8-2&keywords=rv+antenna+booster

Installation details:
http://www.fishhousesupply.com/images/booster.pdf
 

nvrver

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Gary statement is correct,  ?Does your antenna booster (amplifier) switch plate have a 12v outlet in it (cigarette lighter plug)? Many do, though it is not intended to be a high-amperage power source and depends on what the RV maker wired it to.?

I need to clarify, the 12V cigarette lighter plug I have my inverter plugged into is not part of the amplifier it is a separate switched plug Winnebago installed in the TV cabinet for powering 12v TV?s.  The most I have run the Vizio 26" LED-LCD 720p 60Hz HDTV #E261VA & Toshiba DVD VCR Combo #SD-V296 is about 2 to 3 hours continuous at one time off the batteries while dry camped on the Rincon.  Usually we are at RV parks with full hookups and run only on 115v AC. 

The DC to AC 300 watt converter I have is a PORTAWATTZ 300 mfg in China for STATPOWER in Burnaby BC Canada.  It is 300 watt with surg power 500 watt.
Hope this helps, Dick
 

dabrooks

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After all of the good and expert advice I think that just running the generator makes the most sense at this time. It sounds like the extra gas is not significant and running the generator is better for the generator that not running it. Is there and additative that can be added to the main tank ever so often that will help keep the carb on the genny cleaner. I know older small engines (mine is 2001) don't like the ethenol. We have 4 atv's, 2 dirt bikes, 3 portable generators, 3 lawn mowers,1 log splitter and 3 chain saws. I use Star Tron in all of those and they never fail to start. One bottle treats 48 gallons which is enough gas for several months for the equipment. Do you feel it is necessary to treat the gas for the genny or is just running it 2 or 3 times a month sufficent. Again I cannot thank you all enough for the time you devote to helping everyone out.
 

Foto-n-T

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If you run the genset 2 or 3 times a month under load then you can more than likely get away with no stabilizing additive in the fuel.  But what about the first time it sits for three months with ethanol blended fuel in it??  Fuel stabilizer like SeaFoam or Stabil is cheap compared to having to pay someone to fix your generator or buy the parts if you do it yourself.

I'll also add about ethanol blended fuels:  The age of the engine isn't that critical (as long it's new enough to run on unleaded gas).  Actually a carborated engine will take a LOT more punishment from inferior fuels than a fuel injected one.  That is right up until you let an ethanol blended fuel sit in the float bowl too long, ethanol does not age gracefully.
 

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