Power Inverter

[John Stevens]

I'm looking at a 19 inch digital TV, running at 20 watts.

I'll need an inverter to run it off my boat battery and wondering what size inverter is best?

I've read that inverters are "less" efficient at the low end of their power rating, making me think I need the smallest inverter possible to handle the TV load. Is this correct?

TIA,

John

 

[Chuckbear]

John, If you only plan to run the TV than an inverter that will use about 80% power would be best IMO. We use an inverter to run our "entertainment system" exclusively. It does not run off shore power. This protects everything on the circuit. But that includes our 23" flat screen, DVD player/recorder, satellite receiver and power for our over the air antenna. We use a dedicated 750 watt pure sine wave inverter. We have to allow for times when everything is running at the same time. Most of the time it is only the TV and the receiver so not always so efficient but what might be needed. Chuck

 

[Don S/V ILLusion]

If that's the only appliance for which you need power, why not lose the 12V brick in the power line for the Tv and just run it directly off 12VDC? The only caution is that some TVs are sensitive to surges - which TV do you have?

 

[Maine Sail]

John,

If your buying a TV and inverter then consider a 12V TV. There are a few brands that do well and are relatively inexpensive. NAXA, Skyworth, RCA and others make 12V/120V TV's designed for use on a 12V system and they all now offer 12V LED TV's which consume even less power..

Some of the Skyworth models now have spike protection built in so when you start the motor the TV won't fry if you don't have a spike protected starter....

Road Trucker has lots of 12V TV options.

http://www.roadtrucker.com/electronics-4.htm

The inefficiencies of a TV run off inverter power are upwards of 25-35% less inefficient when compared to the same TV off 12V..

 

[dscribner]

I have heard that some inverters supply a modified sine wave that is basically UP-OFF-DOWN as opposed to a smoothly transitioning arc. Some appliances can be damaged by this modified wave. I might be all wet, but I'd ask the question and so some research before you hook up your flat screen.

 

[Benny17441]

A 400W inverter which sells for about $40 and can be plugged in to a 12V socket will more than adequately do the job. Keep the 120V brick as it protects the TV. Do not worry about efficiency as when you are talking about small loads the loss is very small. Percentage numbers may sound big but actual amp loss is nill.

 

[Stu Jackson]

'Ceptin' the real downside of using those 12V cigarette plugs is that they are rarely wired with large enough wiring. Something to check before you go this route. Those plugs were designed for low level charging or actually short time high charging to light the cigar element. I use ours for rechargeable battery charging and the VHF recharge cradle, but would shy away from long term use for computers and TVs unless I upgraded the wiring to the plug. We have a Freedom inverter/charger, so I can use 120V. I know it suck twice as much juice than if I used 12V, but we don't have a TV and never will, so it keeps the laptop going.

Your boat, your choice, but watch the wiring.

 

[John Stevens]

Thanks for all the helpful info. I'm looking at a few different 19 inch tv's.

I just took a look at the 12volt tv's, a little pricier but nice. I would probably seldom use the TV and inverter, just at anchor once in a while.

Thanks,

John

 

[Forrest15112]

I have a 19" LED Insignia from Best Buy that has a 12V wall wart dc supply. You could make up a DC cable and run directly from your 12VDC. It cost less than $200. It's a 12V TV but not sold as that. Mine is a couple of years old, but I'm certain, you can find one. Just trace the power cord off the rear of TV's on display anywhere and read the output of the power supply. If it has just a cord that plugs into the wall, it has a built in power supply and would require an inverter. Mine has power supply like a laptop does, an ac cord to a power supply then a dc cord ( with a round plug) plugs into the television. I think you could save some dough if you shopped around and just looked at the back instead of the front of the TV's. That's sure to get the salesman's attention.

 

[seadaddler]

Upgrade

Yes it would be very good idea to upgrade the 12volt pug on your boat for one of those 400 watt inverters.
I had problems with doing that in my car for our laptop while traveling on long trips with one of those 400 watt inverters when it melted the 12volt plug after using it a few times.
Nick

 

[Ross]

Re: Upgrade

One of my neighbors moved and left behind an emergency power supply for a computer. Normally it is connected to a 115 vac outlet but when there is a power failure it switches to a battery powered inverter. I see no reason that the twelve volt battery couldn't be kept charge with the rest of te ships batteries. This system is rated at 1400 volt amps for a half hour of service.

 

[Benny17441]

Both Stu and Seadler are correct inspect the wiring on your 12V plug and upgrade if necessary. Also make sure the plug fits tight into the receptacle as a loose plug creates heat. You may purchase a locking matched receptacle and plug. Verifying the adequacy of your 12V connection is necessary wether you are using a small inverter or a 12V TV. I mostly operate my TV at the dock with cable progrmming so I prefer a 120V unit. For those few times when I want to catch a football game at anchor or underway I use a hardwired inverter.

 

[monkeybars]

i run a 26" lcd tv with a dvd player also plugged into an 200watt walmart inverter that was less then 25 dollars. it has been working flawlessly for three years now,inverter is hooked directly to battery.all wires stay cool to the touch

 

[John Stevens]

Again, thanks for the ideas. I'm leaning toward a regular tv with the inverter, probably around 200 wt.

Thanks,

John

 

[zeehag]

i found the 400 wtt invertors when plugged into the 12 v outlet do not function. they require wiring to the batteries, as the 12v outlet version is not able to function at over 80-90 watts of usage. read the box it came in--i had to do that to learn this. i use the smaller invertors to save batteries. i have 1000watt, 400 watt, 300 watt, 200 watt and 130 watt invertors--the only one that works in a 12v outlet is a cheapo radio shack 120 v invertor i use with my netbook. that one is not able to be wired into the batteries.

 

[shipwreck66]

750 watt hooked up to a dedicated Group 31 battery to run everything, makes all house 110 plugs usable. Easy to rig it up.

 

[Maine Sail]

750 watt hooked up to a dedicated Group 31 battery to run everything, makes all house 110 plugs usable. Easy to rig it up.

If your vessel also has shore power then you need to have a shore power/inverter transfer switch. This makes it a little more difficult and a bunch more expensive. Best bet is to totally isolate your 120V outlets from the AC panel if not using a generator transfer switch or just install a couple of AC outlets dedicated for only the inverter that can not be run off shore power..

 

[John Stevens]

I don't have shore power on my 26 but I do like the idea of running a 110 outlet to the cabin and keeping the inverter secured under the cockpit, unseen.

Thanks again,

John