Inverter/Charger - Generator Questions

[Link]

First thank you in advance for your input.<br /><br />A couple weeks ago a friend went camping with the missus and 2 grand kids. 28 ft RV Trailer. It was very hot during this time and after 8:30PM he was required to shut his contractors 4000 watt generator off. Meaning no TV, no Microwave and worst, no Air Conditioner!<br /><br />He has convinced himself that this inverter/charger will take the place of a generator. I'm going to have to make the un-pleasant phone call to diappoint him so I just want you to confirm that I'm correct.<br /><br />Three questions:<br />A: Am I correct in that this is just a inverter/charger that is required to hooked into AC to charge the batteries, but when AC is lost it will run the TV etc for a short time.<br /><br />Because of this misleading info he is convinced the thing will turn off the all TVS etc when the batteries get below 10% and recharge them? From themselves???<br /><br />

Tripp Lite's RV2012UL Inverter/Charger is the quiet alternative to gas generators—with no fumes, fuel or noise to deal with! It provides equipment with clean, quiet 120V AC

B:I think a better use of a 1000 dollars would be to invest in a small quiet generator that people 20 feet away wouldn't notice. A friend has a honda 1500 watt that is the size of a tackle box and you can hold a normal conversation with it running at your feet.<br />I would like to know if you agree with me on this.<br /><br />C: Without me being able to give exact specs, about how many watts would the generator need to run the air cond and a TV. Approx? I know that a broad question.<br /><br />Here is the URL The model in question is RV2012UL and will be at the bottom of the page.<br /><br /> http://www.lashen.com/vendors/tripplite/inverters/rv.asp#RV2012UL <br /><br />Thanks again for the help.

 

[cuzner]

Re: Inverter/Charger - Generator Questions

Sounds like it would run an air conditioner, and tv for about 5 minutes before his r v batteries where drained.I could be wrong (math and electrcal are not my best subjects) but I think in general terms 100 watts = 10 amps.I,m a big fan of power inverters, and use a small one on my boat, but they are power pigs, they have cooling fans that suck a lot of juice, and they do get hot wich = wasted energy. They may turn themselves off, but I don't see how they how they can recharge the battery it just drained.The only alternative would be for him to leave his rv running while he is using it.<br /><br /> Hope you can talk some sense into him!<br /><br /> Jim

 

[Paul Moir]

Re: Inverter/Charger - Generator Questions

Yeah, that one isn't magic.<br />The average TV will consume somewhere between 50W and 200W depending on size. Check the back and multiply Amps x 120. The A/C depends on the model too, but window plugin type ones consume 600W-1500W depending on size.<br /><br />(EDITED)<br />All this translates to 4 to 16 amps (@ 12v) for the TV, and 50 to 125 amps (@ 12v) for the A/C. Which'll drain your battery pretty darn quick, even if it's large. Plus, as cuzner points out, these inverters aren't 100% efficient.<br /><br />The ultimate solution is to use one of these fuel cell powered gensets. But they'll need to get a lot cheaper ($6500 for 1000W) and hydrogen will need to get more available for it to be practical. Till then, we're stuck with the normal gas engine generators. I recently used a Misubishi 1200w (I think) that was impressively quiet.

 

[sangerwaker]

Re: Inverter/Charger - Generator Questions

Whoa whoa whoa! 50 to 125 amps for the a/c? Never. Look at the breaker in your house for your central A/C. Chances are it's a 20 or 30 amp on a 240v circuit. Window units that run on 120v run on your regular 15 or 20 amp circuit, right? The formula for AC current is amps=watts divided by volts. For DC current it is the same. If something draws 1500 watts on regular 120v household current, it draws 12.5 amps. I agree that the generator is the best way to go, but at least you should know how to figure out amperage draw. I don't know a lot about inverters, but I can't see how they can recharge the batteries they are drawing from. If that's true, I'm buying several large ones and disconnecting my electrical utilities!<br /><br />Good luck!

 

[Paul Moir]

Re: Inverter/Charger - Generator Questions

sangerwaker - I forgot to say, that that is 50 or 125 amps at 12v, not 120! LOL! That would be one frosty RV if it had a 15KW cooler on it. <br />I presume any inverter this fellow is buying runs off a 12v battery.

 

[sangerwaker]

Re: Inverter/Charger - Generator Questions

Frosty would be an understatement. Sorry, I should have thought of the 12v conversion. I am used to working with household current.

 

[ZmOz]

Re: Inverter/Charger - Generator Questions

Originally posted by cuzner:<br />they have cooling fans that suck a lot of juice, and they do get hot wich = wasted energy.

The fans in inverters use VERY little power...about .15 amps. Most power inverters are around 90% efficient, including what the fan uses, which isn't bad, but still won't run AC for long enough to cool off a trailer...

 

[ndemge]

Re: Inverter/Charger - Generator Questions

I had a Freedom 2500 Inverter Charger 2500 watt contionus, with 100 amp 3 stage charge built in.<br /><br />I hooked this to a 5,500 BTU AC in my garage to test to see if it was big enough to run it in my van.<br /><br />To even get it to start up, I had to turn to fan first, then low cool, then crank up to High cool, as the initial startup current was an incredible load.<br /><br />The AC in a motorhome is usually a MINIMUM of 13,000 BTU.<br /><br />The Freedom 25 was $600 USED, he will need about a 4000 watt inverter to run the AC, looking a couple grand for that.<br /><br />The Honda EU series are SUPER Quiet generators. Don't ever run that contractor genset when I'm camping!<br /><br />For what he would spend on a big enough inverter, and then at least 15 80lb batteries to get him through the night..... he's cheaper getting a genset.<br /><br /><br />I had planned on running the window unit in my van when driving, with 160amp alternator.

 

[Link]

Re: Inverter/Charger - Generator Questions

Thanks for the input guys<br />I just emailed him a link to this thread and he can read it for himself.<br /><br />Link