TV battery discharge while plugged in?

[Peanut]

After a two night stay at a RV park plugged into electric, the TV battery was dead. I did forget to unhook the trailer from the TV, but I would think if anything, the TV battery would be getting a charge not discharging. After unhooking the TV and the unplugging the electric, the AS battery monitor read 12.8 volts. Can someone explain what happened? Thanks.

[xrvr]

What tow vehicle? This should not normally happen. Never has to me in years of camping. Something is wired incorrectly. Peace, jim

[ROBERT CROSS]

12.8v is not a dead battery.



Bob

[Peanut]

The AS battery was at 12.8, not the one in the TV which is a 03 Ford Expedition. I am pretty sure the Ford doesn’t have an isolator because its battery has been drained when previous trailers were left plugged in, but that was without shore power. Guess I’ll have to breakout the voltmeter and poke around when it gets a bit warmer.

[handn]

Sounds to me you have a battery problem in your tow vehicle unrelated to being plugged into your AS.

[tjdonahoe]

Put a load test on the tv battery, check the age of it. ..

[Foiled Again]

This happened to me once. The batteries in my Airstream were near (or at) the end of life. There is always some draw on the trailer's batteries - CO monitor, clock in the microwave, fan on the fridge, etc. So when the Airstream's batteries went dead... looked for more power from the tow vehicle.

Newer vehicles may have an isolation switch that prevents this from happening, but one way or another there's a "gotcha". If you unplug the tow vehicle - you might forget to plug it back in when you depart. Or you might not depart (easily) if your truck's battery dies.

Anyone buying a new Airstream? Check the batteries before you drive it off the lot. Dealers will leave an Airstream sit unlocked on the lot all day with people going in and out, and if someone isn't specifically tasked with turning off everything and putting the unit in "store" mode overnight, by the time the unit is sold the batteries are 3/4 the way to being DOA.

Paula

[robertbrenne]

Sound like everyone has good ideas, just remember the instant on TV s have small amounts of current going through them when turned off.

[Msmoto]

I know that on my 2015, before I disconnected the subwoofer, it was on and drawing power all the time. Overnight, it created enough of a draw, along with some of the other electrical loads, previously mentioned by Foiled Again and robertbrenne, to drop the trailer batteries to below 11 v.

I have subsequently placed a line switch into the subwoofer power supply, and this not only stops the power drain, but also corrects another issue with the new models, that being the hum from the subwoofer when the main cabin LED overhead lights are on.

Oh well...

[Skater]

If I understand the original post, they were camping and plugged in to shore power, and the tow vehicle's battery still went dead. Talking about phantom loads and all is irrelevant if the trailer is plugged in. (Unless the converter is bad, but the trailer batteries were fully charged, so that's unlikely to be the case, too.)

[xrvr]

Interior light left on in TV? Anything else in TV on, radio, etc.? Jim

[ROBERT CROSS]

Originally Posted by handn

Sounds to me you have a battery problem in your tow vehicle unrelated to being plugged into your AS.

Originally Posted by tjdonahoe

Put a load test on the tv battery, check the age of it. ..

Originally Posted by Skater

If I understand the original post, they were camping and plugged in to shore power, and the tow vehicle's battery still went dead. Talking about phantom loads and all is irrelevant if the trailer is plugged in. (Unless the converter is bad, but the trailer batteries were fully charged, so that's unlikely to be the case, too.)

My bad....mis-read the original post.

As noted...charge TV battery, let stabilize for several hours and load test.

Bob

[Wingeezer]

Originally Posted by robertbrenne

Sound like everyone has good ideas, just remember the instant on TV s have small amounts of current going through them when turned off.

In this case, TV=tow vehicle, not television! easy mistake!

Brian.