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.

What is the measured voltage input to the inverter?Also measure the voltage at the battery terminals to compare.

I have a 12vDC tv which functions normally at 9.5vDc input, perhaps even less. Your 14v tv likely can be hooked directly to your 12vdc system bypassing inverter. Worth a try anyway.My wagan elite 400 psw inverter failed a while back. Bummed.If you are.plugging the wagan into through a ciggy plug, ciggy plugs are horrid electrical connections with ever increasing resistance until complete failure.

Isn't it always a low voltage problem w/ an inverter.The fact that the line in is controlled thru a wall switch, would suspect the inverter being too far from the batteries, or the wire being too small.But a volt meter at the tv when turned on will tell the story.

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.

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.

14 volt tv and the inverter squealing. | Good Sam Community

BFL13
Explorer II
Feb 19, 2019
OP seems like someone who would appreciate a Trimetric.

I do have an adapter for paralleling the engine battery with the house battery bank, but I prefer to use a separate maintenance charger on the engine battery. I don't like having the engine batt in parallel with my house AGMs, but cannot prove it is a bad thing--I just don't like it. I made the adapter for when on solar off grid a long time so the solar would also do the engine batt.

I found it way easier to leave the 7300 in place and use a deck-mount converter as a portable charger with clamp-on wiring (cut off end of fat jumper cables). No wiring to do, and you get the charger close to the batteries. The 7300 was still good for when on shore power.
landyacht318
Explorer
Feb 20, 2019
I'd not long term keep a flooded starting battery attached to an RV converter set to keep house AGMs at a happy float voltage.

Flooded batteries are more of a 13.2v float and AGMS 13.6v ish.

I have verified that my 13.6v recommended float AGM will discharge slightly at 13.5v float when there are still loads on the system, or temperatures sub 60f.

BOats use amn 'echo' charger to keep starting battery happy when attached to shore power.

Lots of ways to skin that particular cat.

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14 volt tv and the inverter squealing.

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