Man Cave and the HUGE 12v HDTV search

[Captain Morgan]

Hey folks,

I intend to repro my home theater and man cave and while I'm not apposed to running my huge HDTV from an inverter, I'm just wondering what is the largest 12v HDTV that YOU HAVE??

No theoretical discussions here please - I'm not asking what all could be possible if . . ., just the facts. Have you been able to get a 40", 50" 60" 4k HDTV etc?

Thanks in advance!

.

 

[Domo]

As for myself - I'd only found a 21" 12 VDC TV from Walmart by looking at the ones on display and finding the one with the power supply on the cord.

I did a superficial google search for a replacement 12 VDC power supply for HDTV just to see if that was a way to backtrack to a large TV by checking out compatible model numbers in the descriptions of the found items.

I did not follow the search very deep - however the initial results on the retured search page showed up to 32" TVs - so I'm guessing you could have good luck following that type of search deeper.

Of course your thought of a small plug-in inverter would open the world up for you and perhaps give 120 VAC where you might need to have it for other reasons on occasion.

Post what you find - I'm sure others are interested.

 

[Gary RV_Wizard]

while I'm not apposed to running my huge HDTV from an inverter,

Why not? Granted there is some overhead in using an inverter, but it's probably on the order of 10% vs DC for the same size tv (and same power draw). Watts are watts;  there is no free lunch just because it is DC power. The way to reduce power consumption is to use a smaller tv that neds fewer watts of power to light up the screen.

According to one survey, a typical 32" led tv uses about 18 watts, whether AC or DC.  The overhead of running it with AC power off an inverter increases that around 10%, to 20 watts.  A 40" might increase that to 31 watts and a 55" to 57 watts.

https://understandsolar.com/how-many-watts-does-a-tv-use/

There is a fairly wide spread of wattage for various sizes and types of tvs and the articles on the web sometimes cite different sources that use substantially different numbers. TV Power consumption has been coming down, though, and newer led-backlit models are more power-efficient than older lcd or plasma models.  If shopping for a new tv, pay attention to the wattage requirement.

 

[Lou Schneider]

Pure sine wave inverters are getting inexpensive - here's a couple of 300 watt PSW inverters for $46 and $85 ...

https://www.amazon.com/dp/B07KQ4Q2L5/

https://www.amazon.com/AIMS-Power-PWRI30012S-Inverter-Continuous/dp/B0007911Y8/

Think of using a PSW inverter to power your TV as an insurance policy.  In return for a small premium, it protects the TV against damage from dirty power because it leaves in place all of the filtering in the TV's power supply.

Instead of providing clean and constant 12 Volts DC, an RV's electrical system can vary from less than 12 volts to more than 14.5 volts and can carry dangerous voltage spikes and other noise.

Electronics that are meant to use vehicle power have the necessary filtering to accept this dirty power.  A TV designed to only use clean power from it's external power brick doesn't.  Eliminating the power brick leaves the TV vulnerable even when it's off because the TV doesn't physically disconnect from incoming power, it's always on and idling so it can respond to the remote control.

 

[WILDEBILL308]

What RV do you have? How many/what batteries do you have in your battery bank? Why waste time and money looking for a 12V TV?
Bill

 

[Mark_K5LXP]

Just for giggles I looked up the power draw for a 55" Samsung TV.  125W.  That's about 10 amps nominal at 12V which brings up the issue of voltage drop.  What would the minimum voltage need to be for a "12V" TV?  Will it run all the way down to 10.5V which is the battery lower limit, or poop out at 11V and change, limiting TV run time?  That lower limit is only amplified by the voltage drop in supply wire, so likely one would have to run a dedicated supply line.  An inverter can solve voltage drop and regulation issues as well as eliminate finding a niche TV that may not have all the features you want just so it runs on 12V.

Mark B.
Albuquerque, NM

 

[AStravelers]

Just for giggles I looked up the power draw for a 55" Samsung TV.  125W.  That's about 10 amps nominal at 12V which brings up the issue of voltage drop.  What would the minimum voltage need to be for a "12V" TV?  Will it run all the way down to 10.5V which is the battery lower limit, or poop out at 11V and change, limiting TV run time?  That lower limit is only amplified by the voltage drop in supply wire, so likely one would have to run a dedicated supply line.  An inverter can solve voltage drop and regulation issues as well as eliminate finding a niche TV that may not have all the features you want just so it runs on 12V.

Mark B.
Albuquerque, NM

I bet you got the 125watt figure from the back of the TV or from a specification sheet for the TV.  That number is NOT how many watts the TV actually uses. 

My 43" Samsung LED TV in my RV has a label that states it uses 110 watts.  I am in our RV right now, running on battery.  I just checked the total amp draw of our RV on our battery monitor and then turned on the TV.  The amp draw jumped 3.0 amps, or 36 watts.  That is about 1/3 of the 110 watts on the label. 

I'll bet if you were to do the same test with a 55" Samsung you would find that it pulls about 3.5 amps or about 44 watts, not the 125 watts on the label.

 

[Mark_K5LXP]

That number is NOT how many watts the TV actually uses. 

They're not in a habit of lying on specifications, so if it says it then at some point during operation it's possible.  If it's not during your typical operation then great, but how do you know what conditions consume most and least power?  Do you go for average, typical, best case or worst case?  It's just as much work to run 8ga as 12ga, so there's little economy in under spec'ing the feed. 

Mark B.
Albuquerque, NM

 

[Rob&Deryl]

The tv will draw the most at low voltage and the audio volume turned up to the max and the brightness turned to most bright.

Not typical.

 

[Gary RV_Wizard]

The wattage ratings are always "worst case", since that's what the wiring and breaker need to accommodate, but often the sustained power in typical usage is less. How much less is often guesswork until measured.  If it was just wire gauge and breaker size, it's not a big deal but if operating off-grid and relying on battery power, the actual wattage gets a lot more important.
Many newer tvs automatically adjust the screen backlighting to room conditions, so the actual power usage can change.  That's also why led tvs generally use less power - the backlighting is energy-efficient leds.

 

[AStravelers]

They're not in a habit of lying on specifications, so if it says it then at some point during operation it's possible.  If it's not during your typical operation then great, but how do you know what conditions consume most and least power?  Do you go for average, typical, best case or worst case?  It's just as much work to run 8ga as 12ga, so there's little economy in under spec'ing the feed. 

Mark B.
Albuquerque, NM

There is no question in my mind that it is "possible" that the TV could draw 110 watts.  Keep in mind that if my TV was to draw 9 amps with some surge at start up, that would equate to 108 watts of power draw.  That surge may only last for 1/2 second or even 2 to 3 seconds, but it still pulled 108 watts for that short period of time.  So I assume that the label is correct in that the TV is rated to use 110 watts. 

What is important to me is that when I have the TV on for several hours what is the continuious amps being pulled from my batteries.  Having actually measured the number of amps as three I feel comfortable that most of the time the TV is pulling about 3 amps from my batteries.

No one is saying the MFG is "lying" about the power specification.  They have to put some number on the label and I believe that for many legal reason they sure don't want to put lower numbers than the TV can pull. 

Heck there may be an internal 8 amp fuse that should blow at something over 96 watts.  So putting a rating of 110 watts would cover that.

OOPS!  Just mixed up 120V device with 12V from the battery when writing about an 8amp fuse.  An 8 amp fuse in an 120V device would mean it would draw 960 watts before blowing the fuse.

 

[AStravelers]

The tv will draw the most at low voltage and the audio volume turned up to the max and the brightness turned to most bright.

Not typical.

I actually did that test a few years ago on my LED TV in my RV being power by the batteries through the inverter.  I ran the brightness and sound to the max and then down to very low for both.  At the very best of a few tries I saw maybe a 0.1 amp change in the number of amps showing on my Trimetric battery monitor.

Granted the Trimetric monitor is not a precision instrument in the 0.1amp changes.  However to be significant the TV would need to be changing the amp draw by a half amp or maybe 2 amps with the brightness/sound settings.

Perhaps others that are currently in their RV off of shore power or generator could test their LED TV to see how the sound and brightness changes the amp draw. 

 

[Captain Morgan]

Hi Folks, just swinging back by this topic. The Sony is rated as 305w at 120v, and while I'll surely be running pure sinewave inverter, this set will be on A LOT. I'm just trying to balance how many 120v devices I need at any time.

This 75" will fit just fine right where I want it so I'll just mount it the way I intend and leave it at that.

Thanks to everyone for your contributions.