First the Power Jack and then the AC.....

[ChrisRVnewbie]

This past Thursday we went to our storage lot to get our camper for the weekend and the power Jack wouldn't work. (Side note, 24 hours prior we had turned on the fridge (propane) so it would be cold the next day.) We went ahead and manually cranked the jack and took it home. Plugged it in to the house to make sure we had some power (we did) and went ahead and loaded and went on our way. When we got to the campsite the power jack worked and everything seemed fine. Friday morning got up and showered and when I shut the light off in the bathroom the AC shut off as well. Turned the light back on and the AC came back on??? This is how the majority of the weekend went. Once in a while, we could get away with the AC staying on with all lights off but eventually it would shut off again. As long as we kept a light on say in the bathroom or even above the sink the AC kept running. Also...there would be moments where these lights would flicker until we turned additional lights on. Converter issue??? 2012 Keystone Bullet 294BHS. Oh, I should add, the lights that kept my AC happy also were the ones that would get my converter humming.

[MarkEHansen]

Welcome to the forum!

Was the trailer connected to shore power while in your storage facility?

Keep in mind there are several things in the trailer that use 12V, like the CO detector, LPG detector, and yes, even the fridge will use 12V to power its controller circuits.

Most trailers are sold with a barely-adequate 12V battery. I would not expect it to last through the night - depending on what kind of charge it had when you started.

Some things to think about are:

* When was the last time you fully charged the battery?

* How long was it connected to the trailer without additional charging (during this time, it will be draining with the load imposed by the trailer).

* What type of battery and how large is it?

I'm sure there will be others with better answers.

[Tbos]

Were you plugged into shore power when all this happened? Your AC runs on shore power and should not be affected by the 12V lights. Sounds like a bad connection somewhere in the AC circuit. Maybe it’s getting a ground through the lights.

[ChrisRVnewbie]

We got to our camp site Thursday and was plugged in to shore power by 5pm and everything seemed to be running fine all night until Friday morning when the AC Started shutting off when the light was shut off. This was the first and only light that had been used since when went to sleep the night before. The flickering lights seemed to begun later in the day on Friday.

[ChrisRVnewbie]

It is not connected to power when in storage. It had been without power for several weeks May 12th to be exact so I could see how this would effect the power jack. I can't remember the battery type off the top of my head. The battery had been shut off prior to the night before.

[sourdough]

Depending on the age and condition of the battery I'm betting it's trying to die. Might get it checked out....or replaced. Your thermostat operates on 12vdc as well as the lights.

[MarkEHansen]

What do you mean "the battery had been shut off prior to the night before"?

Even if you disconnect the battery, it will still lose charge over time. If it is connected to the trailer but you disconnected via the "battery disconnect" switch, you'll find that some components in the trailer will still have power in this condition.

You really should not leave your battery in the trailer for long periods without getting a charge from somewhere. It will discharge all the way to zero (% charge) and this is very, very bad for these batteries.

[ChrisRVnewbie]

We have a shut off switch but good to know. We will start pulling the battery when we park it for the week between camping and take it home and leave it on a trickle charger.

[MarkEHansen]

I would not use a trickle charger. This can overcharge batteries. Instead, you should get a smart battery charger/maintainer, like this for example: https://www.amazon.com/dp/B01K87YZ3C

[Tbos]

We have a shut off switch but good to know. We will start pulling the battery when we park it for the week between camping and take it home and leave it on a trickle charger.


Just get some wing nuts to truly disconnect the battery. If it’s good it will maintain the charge for quite a while when not connected to anything. If it’s cold it will deplete faster. When you are in a CG and on shore power the converter should provide enough to run all the lights and the thermostat. If the battery won’t stay charged then I suppose it would cause anything using 12V to have an issue. The converter charges the battery at the same time everything is drawing from the battery. If the converter or battery is bad I believe it could cause this kind of problem. With the battery connected put a meter across the leads while hooked up to shore power. It should be 13.6V
If I’m wrong on my assumptions someone let me know.

[MarkEHansen]

I think there are two issues here. First is the issue of attempting to use the battery after it has set and discharged for some time. I think this is why the power tongue jack would not work when picking up the trailer.

Second is the issue with the Air Conditioner and lights on Friday. I don't know if that can be caused by a bad battery, but it's certainly not out of the question.

I think the battery should be removed from the trailer and taken to an auto parts store to be load tested. If the load test shows the battery is good, then better care of the battery may be all that is needed. The air conditioner may then be a separate issue.

Keep in mind too, that if the battery is dead (which it sounds like it was when the trailer was picked up from storage) just plugging it into the tow vehicle will not give it a good charge (at least not very fast). It would need to go on a real charger to top it off.

[sourdough]

Just get some wing nuts to truly disconnect the battery. If it’s good it will maintain the charge for quite a while when not connected to anything. If it’s cold it will deplete faster. When you are in a CG and on shore power the converter should provide enough to run all the lights and the thermostat. If the battery won’t stay charged then I suppose it would cause anything using 12V to have an issue. The converter charges the battery at the same time everything is drawing from the battery. If the converter or battery is bad I believe it could cause this kind of problem. With the battery connected put a meter across the leads while hooked up to shore power. It should be 13.6V
If I’m wrong on my assumptions someone let me know.


I've had a bad battery (running tandem 12v) cause all kinds of weird things, including the lights, even when plugged into shore power. That's why I'm thinking there may be an issue with the battery not knowing anything about it.

Edit: Also, if the battery was left to discharge completely that reduced its recharge life by about 83% if I recall from the Interstate table (deep cycle/marine battery).

[Frank G]

My thoughts; you have DC grounding issues. Turning off a DC light and your AC quits, scary. This is not a AC voltage issue nor a battery issue. The Air Conditioner has DC relays controlled by the thermostat. A ground is missing and there is a backfeed through the DC light. Not easy to understand or troubleshoot.

[Steveo57]

As a quick experiment you could always use the battery disconnect switch to disconnect the battery and see if the problems go away when your 12 vdc is just being supplied by the converter.

[LHaven]

Talk about synchronicity... see this posting (http://www.keystoneforums.com/forums/showpost.php?p=344495&postcount=3) just arrived from a guy who updated his lights. Salient part:

"Only issue I had was the AC units electronics was getting it's negative led from the ceiling lights and I had to pull a new ground to the AC unit."

[ChrisRVnewbie]

Got the battery checked. 7 months old and already bad. Replaced under warranty. We will find out this weekend if it fixes the issue with the A/C shutting off when certain lights are shut off. Fingers Crossed.

[JRTJH]

Got the battery checked. 7 months old and already bad. Replaced under warranty. We will find out this weekend if it fixes the issue with the A/C shutting off when certain lights are shut off. Fingers Crossed.

Batteries can "just be bad" from the manufacturer and, don't forget that discharging a "hybrid deep cycle/starting battery" below about 60% will (not can) shorten its lifespan. Most battery FAQ explanations suggest that if a battery is discharged below 50% that it shortens the duty cycle to "around 200-350 recharge cycles while never discharging it below 70 percent will extend the duty cycles "into the thousands". That means "abusing" (discharging to 30% or 40% by running the furnace with a single battery can cause it to fail in 4 or 5 months of use.

I'm not suggesting you did this, so don't get upset and "shoot the messenger" but tuck away in the back of your mind the fact that every night you let the battery drop below about 60% watching TV or running the furnace, etc, you're really not doing that single battery any "favors".....

[ChrisRVnewbie]

No Worries, I would never shoot the messenger:). We have never used our camper anywhere without being plugged into shore power except the two times we turned the propane fridge on the night before and to raise the hitch to hook up.

[bbells]

Before doing anything check the voltage in the outlets of your trailer. If the voltage is 100v or less then that could be the cause of all your problems. It is not uncommon for campgrounds to have low voltage. If it is higher, 110-120v, Then I agree with the above post that your AC is being grounded through the lights either due to a short or a bad ground. FYI: A bad ground could also explain why the battery may not be charging.

[apachewolf]

We have a shut off switch but good to know. We will start pulling the battery when we park it for the week between camping and take it home and leave it on a trickle charger.

This is why I have changed the disconnect on ALL my trailer over the years. They came with the positive (+) disconnect and I changed it so the negative (-) cable was disconnected. This way there is NO power to ANYTHING in the camper.

Happy camping.

[MarkEHansen]

Huh? I presume the difference is that the battery disconnect which comes with the trailer doesn't actually disconnect everything (some things still connected include the LP detector, CO detector, etc.).

If you're pulling cables off of the battery, it makes no difference whether you pull the positive or the negative cable. Either one (or both, of course) will completely remove the battery from the trailer.

Even with the above, the battery will still discharge over time on its own.