Powering a TV Onboard

tfox2069 · Jun 15, 2020

I installed a 12v 24” LCD tv into my 2009 Hunter 36. It was really a project for my wife, but I’ve found it nice to have aboard. I don’t use it frequently, but it’s great to watch movies at anchor when it’s pouring outside. I think it cost me $250 off Amazon. I plug it in only when I use it, so no parasitic draw, and I use its 12v plug to connect to a 12v receptacle nearby. I stream video on my iPad or iPhone and plug it directly into the TV, and plug the TV’s audio out into my boat’s stereo receiver to use the onboard speakers in the salon. Saved a bunch of wiring! Ignore the temp white cord on the left side of the TV. All the wiring is under the tv hidden by the shelf fiddle and only pulled out when I watch TV. It’s firmly bolted down to the top of the shelf and tilts and pans. The power draw of the LCD tv is so low as to be negligible when being used. It’s less than my overhead lighting.

Rich Stidger · Jun 15, 2020

I have a 19" 12VDC TV with a built-in DVD player. It is the third unit that I have installed in about 6 years. Two different brands and designed for the RV and trucker market so they should handle vibration well. All three of these have had problems develop within a couple years. In fact the last two I bought from Amazon and when the first of these died, I bought a second but added a 5 year warrantee. I am now dealing with getting that warrantee honored.
Why did I buy a second set that was the same as the one that just died? Because it has gotten nearly impossible to find a 12V TV at anything close to a reasonable price. And I liked the features that the set offered. And I didn't have to re-configure the mounting or power connection.
If I don't get satisfaction with the warrantee, I may have to buy a 120VAC unit. They are much less expensive and there are a variety of them made by popular manufacturers. The only downside is the additional power draw. My 12VDC TV draws about 4A, so that is just a 4AH usage. I suspect that a 120VAC unit will draw 3/4 A at 120V or about 8-9AH at 12V figuring in the losses of the 12V to 120V inverter. That is a big difference if you watch 3-4 hours or more in an evening.

rgranger · Jun 15, 2020

Id double down on a high quality iPad or tablet. They have water proof versions and they can double for navigation, radar, emails etc.

Benny17441 · Jun 15, 2020

An inverter is most efficient when the load matches it's output but it is always good to have a little extra capacity. The average power consumption of a 32" Flat Screen is 30 Watts. A plug in 75 to 100 Watt mini inverter will do it for under $20. Power consumption should be around 3 Amps. (zilch, nada). There could be another option if the TV comes with an external "power brick". Find out what the operatin voltage of the TV is 15V, 18V or whatever and purchase a 12V converter to that voltage. They are cheap and come for all kinds of voltages. They are very efficient but there could be a drawback, Voltage fluctuations on the boat's 12V system are common and some TVs may handle it better than others. Due to the small consumption I would go with the more stable 110V to 12V mini inverter.

Project_Mayhem · Jun 15, 2020

A lot of computer monitors have external power supplies that output 12-19v. running it off of straight DC or from a DC laptop converter would probably be more efficient than an inverter.

I really like @rgranger 's idea of a tablet. Theyre reasonably priced, portable, versatile and they sip power. You could get an external DVD drive if needed

Maine Sail · Jun 16, 2020

Installed a DC TV/DVD when my daughter was very young. Used it maybe three times. Regretted installing it ever since. Why? She just watches on her iPad. We also have a remote hard-drive that we store movies on. The hard drive acts as a hot spot and is wifi so she can just stream movies from the hard drive to her iPad and she can watch from anywhere on the boat.

Terry Cox · Jun 16, 2020

Our 1991 Panasonic tube tv with built-in VHS player died several years ago. Replaced it with same purchased for $12 from a local thrift store. Works great. Otherwise, use an old Mac laptop with built-in DVD/CD player while on the hook. It runs off of a small 12vdc socket inverter that consumes very little power. Happy as an oyster, no pun intended.

jsalley · Jun 16, 2020

I purchased a 24” tv that uses 12 volts from its AC power brick. Went through the TV display at Best Buy and checked the output voltage of each one’s brick. There were several choices that use 12V. Works flawlessly after cutting off the brick and connecting directly to the boat’s 12V system.

Don S/V ILLusion · Jun 16, 2020

jsalley said:
I purchased a 24” tv that uses 12 volts from its AC power brick. Went through the TV display at Best Buy and checked the output voltage of each one’s brick. There were several choices that use 12V. Works flawlessly after cutting off the brick and connecting directly to the boat’s 12V system.

That is the most common (and most cost effective) way to run a TV off of 12VDC. The only drawback to not using a 120VAC monitor is that direct 12v power on a boat is subject to fluctuation beyond the rating of the power board and has resulted in burned out boards.

jsalley · Jun 16, 2020

It’s an Insignia (BB house brand), model NS-24D510NA15. Less than $100 several years ago, IIRC.

Project_Mayhem · Jun 16, 2020

jviss said:
My 15" Macbook Pro uses lots of power. If the battery is not fully charged when I connect it to the inverter it draws more current than the fridge. Once it's fully charged the power consumption drops off some. But, there's no way I know of to tell it to run but not charge the battery, unless you buy the special airplane power cord (obsolete now).

Dim down your screen and keyboard, turn off bluetooth and wifi. You might be able to limit the draw by using a lower wattage charger. They get much warmer but I've never burned one up. It takes longer to charge. Most laptops monitor charge rates. I'm sure you could find a 12v mac charger online

Don S/V ILLusion said:
That is the most common (and most cost effective) way to run a TV off of 12VDC. The only drawback to not using a 120VAC monitor is that direct 12v power on a boat is subject to fluctuation beyond the rating of the power board and has resulted in burned out boards.

As Don pointed out a regulator may be needed. You can find them on amazon for less than $20

LloydB · Jun 16, 2020

hear's a step down DC-DC power supply that should work with a 2017 28" Samsung TV for about 45 watts
amazon.com/dp/B01LWXAC5E?tag=duckduckgo-d-20&linkCode=osi&th=1&psc=1#HLCXComparisonWidget_feature_d

Project_Mayhem · Jun 16, 2020

jviss said:
So, not a regulator, but a DC-DC converter that takes 11 to 15V input and ouputs 12V +/-5% or so, that can handle, say, 40W max. I can't find such a thing. Can you please point out one? Or perhaps I misunderstand.

Theres multiple names for what is often the same device. Look for a buck boost converter. Step down only converters require higher voltage as you just saw. Boost converters can raise the voltage if its too low. Youll have to verify exact functions of each product. Check reviews as descriptions are often lacking. Measure voltages before connecting. Some may require a small load to function correctly. Heres a few that might work

19v - Amazon.com: KNACRO DC 12V 10-17V Step-Up to DC 19V 4A 76W Weatherproof Power Supply Module Converter Regulator Transformer Booster: Home Audio & Theater
Amazon.com: DC Boost Converter, Yeeco 9-45V 12V 24V to 11-50V 36V 48V DC-DC Step Up Voltage Regulator Adjustable Voltage Step Up Power Supply Module with LED Display: Automotive
https://www.amazon.com/Converter-Adjustable-Supply-Module-Display/dp/B0811PLY9D
Amazon.com: [2-Pack] Adjustable DC-DC Buck Boost Converter Automatic Wide Voltage Regulator XL6009 DC to DC 5-32 V to 1.25-35 V Voltage Module: Home Audio & Theater

Powering a TV Onboard

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