Inverter questions

West · 09-24-2015, 11:07 PM

I want to add an inverter to my RV to power a few TV's and DVD players and could use some advice.

Have any of you had problems with electronics using a modified sine? Do I really need a pure sine instead?

What brands and models have you installed that you like or don't like and why?

What options- Automatic switching, separate mountable control panel, ext?

**EA37TS** · 09-24-2015, 11:33 PM

If you are an FMCA member there was an excellent article in the August 2015 issue of Family Motor Coaching Magazine. The article is titled "The Value of Inverters" and answers a lot of the questions you are asking.

If you are a member here is the link to the article.

http://www.fmcmagazine.com/back-issu...inverters.html

West · 09-25-2015, 01:01 AM

I'm not a member of FMCA but thank you for the reply.

**EA37TS** · 09-25-2015, 01:13 AM

To answer some of your questions.

Some high end electronic equipment requires pure sine. Running some equipment on modified sine will cause it to overheat thereby shortening its life.

My Challenger came with an 1800 Watt Xantrex Modified Sine inverter which runs the televisions and residential refrigerator. I have an AGS (Automatic Generator Start) which automatically starts the generator which the batteries reach a certain level of discharge or when the inside of the coach reaches a certain temperature. The system has a control panel which can remain on the inverter or, as in my coach, be mounted inside. One of the key features of the control panel is the ability to push a button and get an accurate charge level of the batteries.

One modification I may make in the future is to connect the 110 outlet at the passenger seat into the inverter circuit so my wife can charge her tablet as we roll down the road.

West · 09-25-2015, 01:28 AM

Do you know what model number your inverter is? Xantrex modified sine inverters seem to be the most common so I like the idea of getting one of those vs an off brand.

Right now I switched the wires at the fuse panel that go to the outlet in my bedroom to 12v instead of 120 and used a 12v TV instead since there was no addiquit 12v wires to use where I would need it but I would like an inverter so all the tv's will work

Mr Sunshine · 09-25-2015, 01:46 AM

I had a add on inverter in my last coach. We used it on the road to run a crock pot, and to charge our cell phones. When overnighting without electric hookups, we used it to run a fan in the bedroom.

I have it mounted on the wall next to the copilot's seat in the Vegas. Cables run from the inverter down to the front cabinet on the right side, then back to the the batteries under the steps.

Saves us hours on the generator. We rarely want the TV when we are without electric hookup, so just run the generator in those rare times. The friend that I got it from had used it to power his TV and DVR player.

**EA37TS** · 09-25-2015, 01:49 AM

Mine is the Xantrex Pro XM 1800. I believe you can go to their web site and download the manual. The manual will give you the battery sizing chart so you can compute how much battery power you need for the equipment you want running off the inverter. The manual is too large to attach on this forum.

ournextstop · 09-25-2015, 02:33 AM

Xantrex and Magnum see to be the two major brands. My previous two RVs had Xantrex this Palazzo has a Magnum ME2012. All have been MSW and we have not had any problems with them running our TVs and other electronics. We do not have any "high end" or sophisticated electronics in the RV. I believe DW's electric coffee pots only last about a year in the RV due to MSW which affects the controls on them. But, I don't know that for sure, just heard others say that is a problem sometimes. Coffee pots are cheap and she is not a happy camper if she does not get her morning shot of the black stuff.
One thing you need to be thinking about is where you will put the battery bank. Probably 4 deep cycle 6v golf start batteries hooked up in serial-parallel config.
Good luck, let us know how it works out!

West · 09-25-2015, 03:31 AM

Thanks for the info guys. That's one big thing I wondered about modified sine. It's making me thing I should spend the extra for a pure sine. The kids like to watch the TV's when driving and no matter how hard I try I can't sleep in so I like to in the morning until everyone else is up but I also like the idea of a ceiling fan at night.

I took the factory batterie out right when I bought it and put that on my cargo trailer and installed 4 large six volt batteries on the RV so I should be good for power but will have to do the math to be sure. I like dstankov's setup that will start the generator automatically.

Forest Grump · 11-10-2015, 02:40 AM

I put a Xantrex Pro 3000w MSW on the back wall of the sewer cabinet. Ran 2/0 wires across to the battery compartment where I put 2 6v Trojan J305H 360 Ah batteries. I hardwired the inverter with 10g Romex up through the disingenuous hole for the heating duct through the existing entry into the electrical bay under the dining L couch through a second transfer switch to a new sub panel. It runs the TV, Microwave, iPhone iPad chargers, toaster, toaster oven, hair dryer but not the granddaughters hair curler.

So we are happy campers. We use from 30 to 45 amps per day. 480 watts of solar replenishes that in 2 hours. We haven't used the generator since the solar install except to exercise it and for the curler.

Chance · 11-10-2015, 01:54 PM

http://www.xantrex.com/documents/tec...-universal.pdf

Modified versus true sine wave discussed. He mentions some issues with electric blankets or coffee makers on MSW.

leshunter · 11-10-2015, 03:44 PM

Will this power Inverter work in an Axis 24.1 to power the TV by running an extension cord to the front cigarette lighter when not connected to power or using the generator and if so how long before could I use a TV without damaging the battery? Thanks-See description below.

"Your RadioShack 140 Watt DC to AC Power Inverter converts 12-volt
vehicle battery power into 115 volts of AC power. You can use your inverter
in your vehicle to operate a TV, VCR, portable computer, lights
for emergency or campsite use, power tools, and many other devices.
The power inverter works with the vehicle engine turned on or off. It
provides a continuous output of up to 140 watts, and sustains a temporary
output of 180 watts for about 5 minutes. It can “cold start” a load
up to 240 watts, and provides the 300 watts (1 cycle @ 60 Hz) of surge
start-up power required by most personal computer monitors and TVs"

Chance · 11-10-2015, 04:28 PM

Quote:

Originally Posted by leshunter

Will this power Inverter work in an Axis 24.1 to power the TV by running an extension cord to the front cigarette lighter when not connected to power or using the generator and if so how long before could I use a TV without damaging the battery? Thanks-See description below.

"Your RadioShack 140 Watt DC to AC Power Inverter converts 12-volt
vehicle battery power into 115 volts of AC power. You can use your inverter
in your vehicle to operate a TV, VCR, portable computer, lights
for emergency or campsite use, power tools, and many other devices.
The power inverter works with the vehicle engine turned on or off. It
provides a continuous output of up to 140 watts, and sustains a temporary
output of 180 watts for about 5 minutes. It can “cold start” a load
up to 240 watts, and provides the 300 watts (1 cycle @ 60 Hz) of surge
start-up power required by most personal computer monitors and TVs"

You don't mention specifics, so I will only mention a few concerns to investigate.

Most new TVs use little power, so yours may fall within the 140 watt rating. You can either check the TVs' actual power draw, look it up in specs, or look on back where most TVs list the power requirement.

If your front cigarette lighter is powered from chassis battery (i.e. -- engine starting battery), I would not connect TV to that battery unless engine was running.

If a TV was using 100 watts, as an example, the inverter would likely require at least 10 Amps at 12 Volts from battery. Therefore, if you start out with a typical 80 to 100 Amp-hour fully-charged battery, you'll only get 3 to 4 hours of TV watching before it approaches 50% of available charge. That assumes nothing else is running.

Bottom line is that there are a lot of variables. TV rating, inverter efficiency, battery capacity, what else may be running, etc... If you can post some of these it may be possible to give you a better answer.

In my opinion, for the typical RV the TV will run a few hours before it runs the "one" house battery down to around 50%. If you are expecting 10 to 20 hours I don't think that's likely.

leshunter · 11-10-2015, 04:45 PM

Chance, Thank you that helps. I know the front cigarette lighter is connected to the dual auxiliary house batteries not the chassis battery. I am looking for options when tailgating or spending a travel night in a rest area or Walmart for using a TV. I probably need to look at the cost of installing a proper inverter and also use the generator. Any other advice is welcomed and appreciated as I am new to all of this. Thanks again.

JamieGeek · 11-10-2015, 06:17 PM

There is a chart about 2/3 the way down this page that gives a decent estimate of the power requirements for TVs:
Electricity usage of an LED, LCD, Plasma, CRT TV or Computer Display - Energy Use Calculator

Given that rule of thumb chart a 140 watt inverter will likely power your TV (I'm assuming its a newer Axis with the 32" TV; the older ones have a smaller TV).

As Chance said, though, its best to get the proper numbers either from the TV itself or by looking it up and grabbing the owner's manual online.

leshunter · 11-10-2015, 06:28 PM

Jamie, Yes it is the new Axis with 32" TV's. So maybe this would work for a couple of hours of TV watching?

JamieGeek · 11-10-2015, 06:40 PM

Quote:

Originally Posted by leshunter

Jamie, Yes it is the new Axis with 32" TV's. So maybe this would work for a couple of hours of TV watching?

Perhaps; to be sure you'll want to look up the TV's specs. Do you know the manufacturer and model #?

leshunter · 11-10-2015, 06:52 PM

Jamie, Thank you. I am getting ready to order. My only hesitation is curiosity of what might be new and improved in the next model. Digital dash and new options would interest me. Thanks again.

Chance · 11-10-2015, 09:39 PM

Quote:

Originally Posted by leshunter

Chance, Thank you that helps. I know the front cigarette lighter is connected to the dual auxiliary house batteries not the chassis battery. I am looking for options when tailgating or spending a travel night in a rest area or Walmart for using a TV. I probably need to look at the cost of installing a proper inverter and also use the generator. Any other advice is welcomed and appreciated as I am new to all of this. Thanks again.

I'm not sure what you mean by "proper" inverter. Going bigger or permanently installed won't necessarily help you get more duration out of batteries -- it would only help if the larger or permanent inverter was more efficient. And just because it's bigger doesn't mean an inverter will be more efficient.

Basically a certain percentage of battery power is converted by the inverter to 120 Volt AC power to run the TV. Obviously a more efficient TV uses less power in the first place. Greater battery capacity helps a lot too (you mention "dual" batteries which is a great start).

I have a portable 400 watt inverter I use to power small items while on road (phone, iPad, and camera chargers, etc.), but also used it to run a TV for days during an extended power outage. When the battery voltage got low I would start the engine and fast idled it for a while. That would charge the battery enough to repeat the cycle.

You may be able to do something similar. If you run the TV off inverter and two batteries for at least 6 hours (assuming nothing else is drawing significant power), then the generator should be able to recharge your batteries in less time. The greater the converter's charging rate the faster the batteries can take over again, thereby saving generator time. Besides, running a 4,000 watt generator to power a 100 watt TV isn't very energy efficient.

Forest Grump · 11-10-2015, 10:05 PM

The size of the inverter versus your needs and or future needs is important. Want to run a microwave or coffee pot then you are going to need a larger inverter and probably batteries. Some inverters canbe hard wired some can't. Some 3,000 watt inverters have two 120v outlets 1500w each. Mr. Coffee 8c doesn't like 1500 watts.

Converters charge your batteries when your generator is running.

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