On Shore Power, Battery Not Being Charged

[jkevin]

I have a Freedom Express travel trailer. I think question is general and not specific to my unit.
I traveled about 10 hours before arriving at the campground. So my battery was fully charged. I hooked up to shore power (30 amp). A day ago I was checking my various tank levels and noticed the battery showed at 1/3 charged. That surprized me, but did not worry me at the time.

Then last night, my refrigerator stopped working (and it let me know it with a loud squeel) and my A/C quite working. I checked the power source. My cord showed it receiving power. I then used an 50 amp to 30 amp adaptor and plugged into the 50 amp circuit. That made no difference. Eventually my lights stopped working.

I then notice on my control panel that the battery registered zero. I still don't know why it was not being charged while on shore power. (I assume there is a converter/inverter issue.) So I hooked up my truck, put a charge in the battery and everything is back to normal.

But, I have a number of questions -
Why isn't the battery charging while on shore power?
If I am on shore power, which is running my A/C, refrigerator, ets., why does my battery need to have a charge?

It's not practical for me to run my truck a couple hours everyday to keep the battery charged.

Can someone please explain to me what is happening?

[bikendan]

Have you checked to see if the converter is charging the battery, when plugged into shore power?

[tomkatb]

On most trailers the hvac system is controlled by a thermostat. Today, they are all digital. Using the battery. Which will not work with a dead battery. So no heat or ac.

Most rv’s will operate without a battery. I think. However I think your converter is a concern. I do not recommend it.

The solution is pretty simple. Get your voltmeter out and see where the electricity is an issue. Your converter may have fuses. The plug may be bad. The battery connections are an issue sometimes.

The batteries should read 12.6 fully charged. Now, if the converter was working the battery would read 13.5 or higher while charging. Is the breaker on. You would be surprised how many folks do not know how to reset the breaker.

Should become obvious quickly.

Recharging with the tv is usually not possible. Usually you are only getting a trickle charge in the rv. Well, if you can wait, 200 hours, then maybe. Motor homes are wired differently.

[jkevin]

Thanks. The converter circuit breaker is on. So that is not a problem. All the AC electricity breakers are fine. This seems to indicate to me that the converter is malfunctioning. I travelled to a new campground today. The hour of driving did replenish some of the battery. The air conditioning system is digital. Until the battery was dead, it still operated. But the air conditioning system would only humm then cut off. I have not tried to locate the converter, in case it has a fuse or reset button.

What I still do not understand is why the battery and its level of charge affects the ability of the shore power to power appliances like the A/C and refigerator.

Thanks again for your help. I'll do some more trouble shooting. Any other thoughts or comments are appreciated.

Kevin

[TitanMike]

Originally Posted by jkevin

Thanks. The converter circuit breaker is on. So that is not a problem. All the AC electricity breakers are fine. This seems to indicate to me that the converter is malfunctioning. I travelled to a new campground today. The hour of driving did replenish some of the battery. The air conditioning system is digital. Until the battery was dead, it still operated. But the air conditioning system would only humm then cut off. I have not tried to locate the converter, in case it has a fuse or reset button.

What I still do not understand is why the battery and its level of charge affects the ability of the shore power to power appliances like the A/C and refigerator.

Thanks again for your help. I'll do some more trouble shooting. Any other thoughts or comments are appreciated.

Kevin

Most common causesof the problem you describe,


Reverse polarity fuses at converter are 'blown' or bad converter.

Since all works when batteries are charged but won't charge with Shore power, those are about all that remains.

First check the Reverse Polarity fuses which are usually in the power distribution center and somewhat hidden below and to the left of the 12 v fuse stack.

If your converter is a "Deck Mount" and not contained inside the power center the R/P fuses are usually mounted on it on the output end.

Check these with a Multimeter set for "Ohms/Resistance" and each fuse (when removed) should read Zero Ohms.

If they're OK, pretty much leaning to a bad converter.

[jbflag21ds]

Unless you have lithium battery, running your batteries dead has impacted their life span.

Also, the fridge needs 12V to power the control board, even if on shore power. The A/C needs 12V for the t-stat. Heat too but it uses 12V for the blower so it won't run anyway. That is why those were not working.

The converter could be bad. Flip the converter breaker off and on to reset it. If you don't get 12V out from it then its most likely bad.

[tomkatb]

The 12 supplies power to the circuit board that operates the system.

M fridge has 12 volt. 120 ac and gas to it. With no 12 volt it will do nothing. Same for the rv fridge. The ac units have 12 volt controls and 120 ac powers the motors. The furnace has a 12 volt control board plus gas. My oven has gas to it. However without 12 volt the igniter does not fire up the burners or oven.

You have to be handy. These systems are kind of complicated and due to the abuse from driving our highways things. fall out etc.

First step is to make sure there is 120 ac to the converter. I recommend you turn the converter breaker to the off position and then turn it on. Then unplug the converter and verify ac at the plug. Check wires for tightness on the converter. Verify there is 12 volt on the wires to the battery or fuse panel. Should read 10-12.56 volts. Over 13 if the converter is on.

Be careful. Working hot is dangerous.

Converters are pretty tough. I think it is likely you have a loose connection or burnt fuse.

[glen1971]

Originally Posted by jkevin

I have a Freedom Express travel trailer. I think question is general and not specific to my unit.
I traveled about 10 hours before arriving at the campground. So my battery was fully charged. I hooked up to shore power (30 amp). A day ago I was checking my various tank levels and noticed the battery showed at 1/3 charged. That surprized me, but did not worry me at the time.

Then last night, my refrigerator stopped working (and it let me know it with a loud squeel) and my A/C quite working. I checked the power source. My cord showed it receiving power. I then used an 50 amp to 30 amp adaptor and plugged into the 50 amp circuit. That made no difference. Eventually my lights stopped working.

I then notice on my control panel that the battery registered zero. I still don't know why it was not being charged while on shore power. (I assume there is a converter/inverter issue.) So I hooked up my truck, put a charge in the battery and everything is back to normal.

But, I have a number of questions -
Why isn't the battery charging while on shore power?
If I am on shore power, which is running my A/C, refrigerator, ets., why does my battery need to have a charge?

It's not practical for me to run my truck a couple hours everyday to keep the battery charged.

Can someone please explain to me what is happening?

IMO...
1. What makes you know that your batteries were fully charged? You said you drove for 10 hours, so they're charged. Did you start with your trailer plugged in? If not, they may not be charged to start with.
2. When you're plugged in to shore power and your batteries read 1/3 charged, that says you hadn't been charging since you plugged in, or didn't start with your batteries fully charged.
3. When you said your A/C quit working, we assume it was before?
4. Two hours a day with your truck will barely be enough, if even enough, to top up your batteries from the parasitic loads on your trailer.
5. What voltages did you see? Both AC and DC, taken with a meter. Looking at a breaker and assuming there is power there, or it's all good is wrong on so many levels. Especially when troubleshooting. Check at all sources - batteries, shore connection, converter, breakers, etc.
6. Are your batteries sealed or flooded? If flooded, are the levels correct?
7. Battery terminations clean and tight?

[jkevin]

I appreciate everyone's input. Between the comments and advice I've received here, from others at the campground and a little hands-on effort on my end (with more to come), this has been a great learning experience. Although I still have more to understand as I dig into the issue(s), this sort of thing is one of the "fun" parts of owning an RV.

We'll spend the night tonight with one of our daughters who live 15 minutes from the campground, then head home tomorrow and Saturday. I plan to work on this once I'm home. I'm sure this experience will come in handy as we continue to travel and camp for the next 15-20 years (hopefully). (The converter is below the fuse box.)


Thanks again. Kevin

[chriscowles]

Don't assume your tow vehicle will fully charge your battery, regardless of how long you tow. The alternator can but the gauge of the wire between the alternator and wire is too small to provide anything other than a trickle. If you have a 12V compressor refrigerator (that is not stated) it requires a lot more than your truck connection is providing. Therefore there's a net drain on the battery.

Also, when you run your truck for a little while to get a charge, it's probably only a surface charge. If you measure the voltage of the battery an hour after you disconnect the truck you may be surprised by how low it actually is.

What kind of battery do you have? By that, I mean what size (Group 24, Group 27, GC2, etc.), what type (flooded lead acid, AGM), and does it say marine? Or deep cycle? Marine batteries are a compromise of a starter battery for the boat engine and deep cycle for lights and appliances. A true deep cycle battery can't start a boat engine, but that's what you want for a trailer. They hold more of a charge.

[Duner733]

I have a pup 16fq having a similar issue
I have done all the checks it now at the point of pulling the converter.
My question before I pull - does anyone know if there are fuses on the converter or are they all at the breaker box.
I have seen videos of other converters that have them on.

[Ron045]

Before you pull the converter... Did you put a meter on your battery to determine it was truly low? Did you put a meter on your battery switch?

I had a similar problem and thought it was the battery or the converter but the real problem was the switch.

It's worth a 5 minute check before you start pulling components.

Ron

https://youtu.be/lrDkmpkhXQA

[baint]

Disconnect the shore power cord and then remove the battery cable at the battery. Reconnect shore power and check voltage across the battery cables to determine if the converter is supplying DC power to the batteries. Check the lights in the trailer with the battery disconnected. If the converter is working you will have lights and should have DC power across the disconnected battery cables. If no lights or power at the battery cables, the converter is not working.

[Duner733]

We replaced the battery and have been checking.
Not sure I know where the battery switch is.
Going to disconnect and check.

[Duner733]

Gonna have to step away from it for a bit.
Did the steps above and everything checked out.
Oddly, the inside voltmeter started running high.
Btw, I have the 50amp solar panel and the sun is out.
Thank his for the outside fridge lol. And we are heading home tomorrow.

[njfishing]

Great advise above. First thing I would do is get a meter, set it to volts and put one lead on the positive side of the battery and the other on the negative. If you are not plugged into power, you’ll be checking the state of your batteries charge and you can use this grid to determine where your battery is at. You want to try and recharge your battery before it gets below 12.06 (50% in the chart attached). If you regularly run it down lower then that you’ll shorten its life.

Now plug in and see if your converter/charger is charging your battery. You should see at least 13.2 on the meter and if the battery is really drained, you could see upwards of 14 volts since your charger should go into bulk charging mode. Once it gets more of a charge it should settle back down to 13.4 and then 13.2.

[jkevin]

I made the original post. When I got home I was able to do some work and figure out the problem. Maybe this will help you.

I charged fully-charged my batter (12.8 volts) and hooked it up to the trailer. I also connected to shore power.

I tested the volts coming into the AC circuit breakers from the shore power by applying my volt meter to both the ground (green wire) & screw in the Converter circuit breaker, and the nuetral wire (white) & the Converter circuit breaker. In both caes, Shore power was delivering elctric current, 122 VAC.

I then tested the electric current being delivered by the Converter to the DC fuse panel. It was delivering 13.6 volts.

I then went to the battery. It read 12.8 volts, not the 13.6 that was being supplied by the Converter.

There are two 40 amp fuses in my DC panel. The electric current from the Converter passes through these. They were both blown.

So, please check them as part of your process.

I don't know what could have caused my problem. I always use a surge protector. I suspect the converter. But am not sure. Need more research and will take any thoughts about this from members of the forum.

[Herk7769]

There is a resettable circuit current limiter very close to the metal umbilical junction box.

On the frame of a travel trailer and under the pin box on a 5th wheel.

On the short side of the limiter is a button; press it in until it resets.

Traveling and do not have immediate access to my library to provide pictures.

High current from the truck to a low or dead battery can trip this limiter. The converter will not charge the battery if this limiter is tripped.

[chriscowles]

Originally Posted by jkevin

... There are two 40 amp fuses in my DC panel. The electric current from the Converter passes through these. They were both blown.

So, please check them as part of your process.

I don't know what could have caused my problem. I always use a surge protector. I suspect the converter. But am not sure. Need more research and will take any thoughts about this from members of the forum.

I believe the 40A fuses are the reverse polarity fuses. If I'm correct, somebody connected the battery cables to the wrong posts, at least once.

[baint]

Those are reverse polarity fuses and they only blow if the battery is connected wrong and they blow immediately.