Low battery warning even when plugged into truck

[EdPav]

I have had issues in the past with the internal power only working when connected to shore power. Camping World checked all connections and said the battery was bad. I replaced the battery and everything seemed to work well. Today, after being in storage for a few months, I hooked up my new , charged battery and plugged into my truck to open the slides. Now I’m getting a “low battery” warning and the slides stop working. I don’t get it. If the RV is pulling 12w from the truck why am I getting a low battery warning? Shouldn’t it draw the power it needs Fromm there?

 

[chuckster57]

What year/model of RV and truck?

 

[EdPav]

2021 Keystone Cougar 32RLI. 2021 Ford F250.

 

[chuckster57]

When your plugged into the truck, is the truck running? You should have a relay that doesn’t energize the charge line without the engine running. You may want to verify 12V at the truck 7way connection

 

[EdPav]

Oh ya, it’s running. Just like when I’m towing it.

 

[chuckster57]

Ok, But have you verified that you have 12VDC at the truck end of the umbilical cord?

 

[RacerX-KEY]

The connectors to the truck via the seven way adapter doesn’t supply a lot of amps. Think of it as a trickle charge. The slides and auto level draw a lot of power. Much more than can be supplied thru that connection. It sounds like your battery is either weak or disconnected. Double check your battery disconnect at the giggy box and make sure your battery is really full.

 

[chuckster57]

The connectors to the truck via the seven way adapter doesn’t supply a lot of amps. Think of it as a trickle charge. The slides and auto level draw a lot of power. Much more than can be supplied thru that connection. It sounds like your battery is either weak or disconnected. Double check your battery disconnect at the giggy box and make sure your battery is really full.

We use a forklift at work that has a small alt/battery with 12Ga duplex to a 7way mounted on the lift. Running, it will open slides even without a battery……just sayin.

 

[NH_Bulldog]

So to clarify, your trailer was in storage and you brought along a fully charged battery with you, installed it in the camper, and nothing works? Have you checked the reverse polarity fuses on the converter?

The slides draw a lot of power and a fully charged battery is needed and should provide many, many cycles of opening and closing the slides plus tongue jack, etc. all on it’s own. That being said, even with a dead battery in the camper the truck “should” have enough juice to operate the slide.

So have you checked the trailer chassis ground, and the auto reset breakers on the tongue? Have you checked to see if there is any power from the truck? You want voltage at pin 4 of the 7-way plug. When I used to keep my prior camper in storage, I would always bring my booster/jump-starter pack instead of one of the heavy lead acid batteries I used at the time, and the booster pack would easily power the camper and slides.

 

[Eman85]

Do you have a voltmeter? Connect the voltmeter to the battery of the trailer and get a reading. Then connect the truck with it running and get a reading. Voltage at the battery should be min. 12.6 then with the truck min 13.5 go from there.

 

[RacerX-KEY]

We use a forklift at work that has a small alt/battery with 12Ga duplex to a 7way mounted on the lift. Running, it will open slides even without a battery……just sayin.

Our 2016 F350 only delivers up to about 5 amps via the 7-way due to the length of wire and small guage . The Lippert 4 point ground control uses approximately 9-18 amps per leg (protected by 35 amp fuses) if running 2 at a time (say front or back) I doubt it would work (very well) with just the seven way amperage supply. It needs a lot of battery to draw on or an active converter. The 2021 model F250 may deliver more but the length of the wire from the battery to the trailer is long.

 

[flybouy]

Have you checked the two reverse polarity fuses on the converter? If you reverse the polarity of the cables on the battery even for a nano second the fuses will blow. Price of advice ... if the 7 way plug doesn't deliver enough power then turn the truck around and use a good set of jumper cables to power the battery.

 

[Pull Toy]

As suggested, make sure you’re getting 12v on pin 4 from your tow vehicle. Even though my truck came with the tow package, the fuse had to be inserted to activate the plug voltage. Without that feature, you will always have battery issues.

Even with dual batteries, I try to be on shore power when using my hydraulics. When this isn’t possible, a fully charged battery is a must.
Good luck.

 

[EdPav]

I have had issues in the past with the internal power only working when connected to shore power. Camping World checked all connections and said the battery was bad. I replaced the battery and everything seemed to work well. Today, after being in storage for a few months, I hooked up my new , charged battery and plugged into my truck to open the slides. Now I’m getting a “low battery” warning and the slides stop working. I don’t get it. If the RV is pulling 12w from the truck why am I getting a low battery warning? Shouldn’t it draw the power it needs Fromm there?

Update on issue: Checked to ensure battery is at full power. It is. Checked truck outputs and all are working properly. Now I get a "Battery 1 low voltage 10.5V" warning on my display and not enough power to open a slide. Why would my battery be good (I actually have tried 2 fully charged batteries to be sure), but only registering 10.5V inside? Very frustrating!

 

[NH_Bulldog]

Have you checked the ground wire on the trailer, the connections in the junction box (or Giggy box depending on when your unit was built), and the auto-reset breakers on the tongue (all of which were previously pointed out by more than one person)?

 

[EdPav]

I did not check the ground wire or reset breakers because I just had it in for service 2 months ago and they insisted all those connections were fine!

 

[JRTJH]

Have you actually disconnected BOTH batteries from the trailer, let them sit for about 2 hours, then performed a "cell by cell specific gravity test" ??? If not, I'd recommend that before doing any further "exploration of the trailer systems" ....

 

[JRTJH]

I did not check the ground wire or reset breakers because I just had it in for service 2 months ago and they insisted all those connections were fine!

A lot can change in two months... Corrosion on the Giggy Box battery switch, failure of a DC mini-breaker, a "bolt head" on the ground connection breaking off from the RV service center overtightening it.... Lots of potential for things to change in 60 days....

 

[Eman85]

Trailer is seeing 10.5 volts, what does your voltmeter show? What does it show when slide is activated? Sounds like a bad connection, insisting and assuming, I'd remove and clean. Bad ground can easily cause what you're seeing.

 

[RacerX-KEY]

Agree with items already mentioned to check. I would also make sure all other power was turned off including the dc fridge while testing. Also I have been stung before where a battery tests fine in voltage but once a load is attached the voltage sags and drops quickly. Using voltage only to test the battery will not always find a weak battery.

Turning the truck around and jumping the battery from a running truck while trying to operate the slide might indicate whether it is a power issue or something else? Your rig has three slides, does it happen no matter what slide is operated?