14 volt tv and the inverter squealing.

[klutchdust]

My Cambria has a 14 volt/35W TV in the bedroom.(typical power 18W) It is powered by a Samsung ac/dc adapter ( 35w) and that is plugged into a Wagan Elite 400W pro dc to ac pure sine inverter.

Now, when it was first installed the tv operated off of the house batteries. Now when it is powered on from the house batteries there is a loud squeal. The inverter does say that IF the input power drops the inverter may make a beeping sound then it will power off.

The house batteries are fully charged when this happens. The 12 volt input power to the inverter is controlled by a wall switch factory installed.


What went wrong.

[klutchdust]

Parallax electronic 7300 series

[time2roll]

Post what converter you have. Might be very good.

[klutchdust]

landyacht318 wrote:
Few dried up batteries perform properly after refilling. An extended recharge at higher voltages is usually required to get specific gravity back to 1.275 range.

My wagan elite 400w psw when it failed was emitting that high pitched whine that would appear once turned off. Instantly when turning it on. I fond internal fuses blown and on replacement it could not handle over 300 watts. A month later it refused to fire up at all.

Sometimes the easiest way to get the correct barrell plug connector is to buy an inexpensive universal laptop car adapter. Double check polarity before splicing it to 12.x vdc

If inverter powers tv with engine running or.plugged in and converter holding higher voltage then your batteries might have been toasted when you ran them dry.

Which then brings into question the proper function of converter

Having the original converter that came with the rig in 2009 and with the new batteries coming soon, it may be time to look into replacing that piece.Suggestions for a replacement would be helpful.

[klutchdust]

pianotuna wrote:
I would wire around the switch. In fact, I would direct wire to the battery bank with nice thick wire--say #10.

Have you attempted to run the device on DC without the inverter at all?

Not yet but that will be my next move. Once time allows, the Trojans batteries will be replaced.

[BFL13]

My adventure was making an adapter to go from one 12v socket to another using two 12v plugs with built in wires that I had cut off from where they were.

Joining the two plugs' wires to maintain polarity needed some multimeter work to get it right. 😞

(For the curious, this is for maintaining the engine battery from the house battery on solar or converter. Goes from the house 12v socket at the television antenna panel above the dash cig lighter socket on engine battery.)

[landyacht318]

BFL13 wrote:
LY wrote:

🙂 Got to be a story there! Yes, use the multimeter to see if there is a minus sign before the voltage reading to tell if you are are reversed.

Well, I have not reverse polaritied TV's or laptops. My warning stems from on of the 'universal' adapters being able to easily reverse the polarity by flipping the barrell plug over on the receptacle, though some of them had different size pins so an accidental unhooking and quick return would not fry something.

I do use a laptop car adapter, for a 19.5v Dell, but these plugs have a third center pin inside the barrell, so a universal will not work properly, at least to both power the laptop and charge the battery.

What I have reversed the polarity on is cheap voltage buckers, the 5 for 11 dollar type, or PWM motor speed controllers.

That said if the OP really wanted to, they could buy a simple DC voltage booster/ step up converter and set it to 14 volts. In my experience the buckers hold a very steady voltage once set.


My Tv is rated for 18 watts yet rarley exceeds 12.

This DC to DC voltage booster is rated at 4 amps, should be more than enough for a 35 watt max TV, unless input voltage is falling much below 9vDC, which would mean very resistive undersized wiring/bad connections or bad battery or any combo of all three:

https://www.amazon.com/RioRand-Converter-Voltage-Adjustable-Circuit/dp/B071H39ZN5/ref=sr_1_4?ie=UTF8...

I have added heatsinks to the processor chips of my buckers when expecting to approach their amp rating, these are peel and stick:

https://www.amazon.com/dp/B07H16X2Q2/ref=sspa_dk_detail_0?psc=1&pd_rd_i=B07H16X2Q2

This approach is Likely a lot more efficient than the double conversion with an AC/DC brick on an inverter too. The Wagan elite 400psw inverter fan did not become audible until the 150 watt range in my experience, but inverters can be noisy enough to knock out antenna tv channels. I do not notice any noise on my buckers, but my laptop dc to dc, as well as my AC to DC converter knock out actual channel 8 and 10, which are quite strong in my local.

[pianotuna]

I would wire around the switch. In fact, I would direct wire to the battery bank with nice thick wire--say #10.

Have you attempted to run the device on DC without the inverter at all?

[BFL13]

LY wrote: "Sometimes the easiest way to get the correct barrell plug connector is to buy an inexpensive universal laptop car adapter. Double check polarity before splicing it to 12.x vdc"

🙂 Got to be a story there! Yes, use the multimeter to see if there is a minus sign before the voltage reading to tell if you are are reversed.

[landyacht318]

A load tester is hardly necessary in this diagnosis. If 18 watts of tv alaong witth voltage drop on the wiring to inverter are enough to make low voltage alarm on inverter scream. Then turning on all lights and dc loads would similarly drop voltage.

Any load can be considered a test. Bigger loads just reveal more.

[klutchdust]

Great ideas, thanks. Going to get a load tester and check the batteries first.

[Johno02]

If a battery has only one or two cells that are bad, it will act like wnat you are describing. After charging, it will show full voltage,, but will drop quickly with any load at all, and will output low voltage to a load, because some of the cells are not pulling their part. Especially after having a low water condition. So have a full load test done.

[time2roll]

If you do replace the inverter consider wiring it into the branch circuit you use for the tv. I recommend 300-350 watts from GoPower or Victron as a replacement.

[landyacht318]

Few dried up batteries perform properly after refilling. An extended recharge at higher voltages is usually required to get specific gravity back to 1.275 range.

My wagan elite 400w psw when it failed was emitting that high pitched whine that would appear once turned off. Instantly when turning it on. I fond internal fuses blown and on replacement it could not handle over 300 watts. A month later it refused to fire up at all.

Sometimes the easiest way to get the correct barrell plug connector is to buy an inexpensive universal laptop car adapter. Double check polarity before splicing it to 12.x vdc

If inverter powers tv with engine running or.plugged in and converter holding higher voltage then your batteries might have been toasted when you ran them dry.

Which then brings into question the proper function of converter

[time2roll]

If the battery power went from 13.4 to 12.0 basically just powering this item then it would seem the batteries have severely diminished capacity or were not really charged. Although usually these inverters do not complain until you get to 11.0 volts or below. Yes have the batteries checked. Consider a bench test of the inverter with a known solid 12.5+ volt DC supply such as the chassis battery with the engine running.

[klutchdust]

time2roll,
I measured the battery voltage and the connections at the inverter, both 13.4 volts. I turned on and was running the front Tv off of the house batteries and the house inverter and all was well for a few minutes then the high pitch whine started. I checked the battery voltage and it dropped to 12 volts already. My Trojans T-105 were purchased 8/15. Maybe they have are due to be changed.
One incident i am embarrassed to admit is last spring I checked my batteries and they were almost out of water. I am better than that. I filled with distilled water and they have been performing quite well but I wonder if that was the beginning of their demise.

Landyacht, I may just try that. I would have to come up with a plug similar to what is on the tv now.The inverter is hardwired to a wall switch.

After having a service port failure in my dining area charging my phone ,I reluctantly use those "cigarette lighter" ports or trust them.