Battery Power issue

[tullywork]

First off, thanks to all those that post regularly, we just bought our first RV four weeks ago, and I can't even begin to tell you how helpful the content on this forum has been - solved MANY issues (maybe too many to list) by just searching through the different posts. SO THANKS!

Party of 5 here (three young kids - four if you count the dog) picked up a 2015 Windsport 34J - already took it on our first 'trial run' trip up and down the east coast and learned a TON along the way (most of the issues were more my understanding of the RV vs. actual problems with it - but certainly a couple minor ones of those too).

I've seen similar postings to this latest issue, but it's got me stumped, so I'm hopeful someone can help, apologize in advance for any bad terminology or lingo.

Recently the house doesn't have any power (lights/etc) when we enter (it used to work fine - just stopped at the end of our trip), used to, but suddenly stopped, engine works fine and generator fires up and powers on the interior lights and everything else (now it does - had to replace the house batteries after learning about the 'emergency start' switch when the batteries were too low). The RV is in 'USE' (or at least I've pushed the button up that way numerous times trying to see if that's the issue). All the breakers that I can find don't appear tripped.

The house power (lights/etc) works fine on shore power and when the generator is running, the truck engine fires up right away as does the generator, when I check the batteries on the XM1000 shows the batteries they show >12v now when I enter the RV after a couple of days (previously it was showing ~7v)

I had issues with the auto leveler, which led me to discover the breakers near the batteries. I've looked under the bed at all the electronics and I don't see any breakers there.

The attached picture shows the three breakers that are in the basement compartment with the house batteries.

Today I discovered one of the wires, specifically attached to the rear most breaker (left most in the attached picture in the circle labeled #1) is not connected to anything. The interior lights weren't turning on when the batteries were registered around 7v before we got new batteries installed by a local mechanic, but I didn't notice the 'unconnected' wire then, today I noticed the wire wasn't attached to anything, and I'm not sure if it's the same issue or something different entirely. Not sure if it was never connected to anything or if the wire was missed by the mechanic (it was a shop that wasn't familiar with RVs or Marine batteries, but were willing to help me out).

I'll start to dig around to see if I can't figure out if that wire should be connected and how / to what....but appreciate any other ideas or help!

Thanks very much in advance! Looking forward to many RV adventures!

[cavie]

Welcome. You have a lot to learn but you will get thru it. Yes. That wire must be hook up. I just can't tell where from that picture. It is the cause of your dead batteries. It would appear to go on the front left post but I don't know for sure.

There are two electric systems in your RV. 12 volts and 120 volts. When we say POWER in the RV world that usually refers to 120 volt electric power. All you lighting and control circuits for equipment is 12 volts. It is supplied by a device called a Converter which changes 120 volts to 12 volts. The converter, or in some cases Inverter/charger, powers 12 volt and charges the batteries. When hooked to shore power. Anything under 12 volts on the batteries is a a 1/2 dead battery. They should read 12.6. Charging voltage should be 13.6 or something close.

The other device we have is called an Inverter It changes 12 volts into 120 volts. You can power some 120 volt stuff with this when not plugged into shore power.

It looks to be two 12 volt batteries in parallel. I could be wrong. The generator is not powering you interior lights. It is 120 volts. Your lights are 12 volts.

There is a device called a "Battery Disconnect Switch" That controls a latching relay. That must be ON or IN USE in order to keep the batteries charged. It is usually found at the entry door. Most have a light. The light usually shows that 12 volts is present. It is not an ON/OFF indicator. I keep saying Usually because some one will always jump in and say "But Mine Does not".

The latching relay appears to be behind the batteries with the Breakers. That's the part I can not see well. It could be anywhere. It might be under the bed. Looks like an old starter solenoid. I'm sure someone will jump in here and help with this. Maybe you can get a few close ups pics of the things behind the batteries and a pic of the tops of the batteries. Perhaps you can remove the carrying straps for clarity? We need to follow the wiring to see where that loose cable goes.

There is an electric breaker box in your rig that has all the 120 volt circuit breakers in it just like your house. This is where your converter is located. You have a 50 amp service. This service is 120/240 meaning you have 240 volts to the main circuit breaker. Just like your house. BUT you can not access 240 volts unless yours is a high end unit with 240 volt dryer and induction cook top.

The Inverter will be mounted closer to the batteries. Again Usually.

You tube is your friend! Right now we need to figure out where that battery cable is supposed to be hooked up.

Are you confused yet?

[tullywork]

LOL - nope, think I follow, thanks. I have a picture of all the wiring under the bed (attached) and I found the converter (at least what I think is the converter - grey box under all the wires), how would I know if it was the issue/not working correctly? Is it possible/likely that the disconnected wire in the battery compartment is the converter power wire? Also attached a pic i took yesterday of the wires behind the batteries, it looks like one of the thick red wires is coming out of a larger bundle and going to that 50A breaker, which then is the 'disconnected' wire that's hanging on the side of the battery in the first picture

I'll try to get some more pictures later today when i go to the RV.

Also, would a GFCI outlet be at play here, doesn't sound like it since that would be the 120v vs. the 12v.

I'll dig into more about batteries on youtube too, Thanks for your help!

[javelin]

I am not familiar with your coach specifics, so the following is just my “guess/observations” based on your pictures only.
First off most mechanics I know would be smart enough to take pictures of the coach battery wiring before replacing the batteries and then re-connecting them.....especially in a typical RV cabling rats nest. If that cable was already disconnected before the mechanic opened things up he should have advised you and at least taped it up, if he did not know where it should be connected. If you drive anywhere for this to be fixed/worked on, tape up the loose connection to be safe.
Secondly, while 12vdc will not electrocute you, the current that can be supplied by your parallel connected 12vdc coach batteries, can vaporize a crescent wrench, ring on your finger or watch on your wrist, in seconds, with potential burns to you or sparks and fire. So if you don’t know anything about electricity I highly suggest an RV tech (mobile or Dealer) help you out. Also, buy yourself an inexpensive digital multi-meter and learn how to use it......DC voltmeter part would be useful in this case to test voltages on the loose cable and either side of the 50 amp breaker.


So Cavie is probably correct with the loose cable likely going to front left battery +12vdc terminal (but any loose cable like that in a battery bay is a potential meltdown waiting to happen, if a DC breaker does not trip open to save the day). Looking at your battery pictures it “looks like” the loose cable comes from one of the terminals on the back of the 50 amp breaker; the other side of the 50 amp breaker looks like it connects to a red wire going into a black plastic wire loom.......”possibly” coming from the latching relay (the small black box shown in the lower left corner of your converter picture). The latching relay is what your use/store switch controls to connect coach batteries to the converter fuse panel (through the 50 amp breaker). If this is true, then your converter is not charging the coach batteries when you are on shore or generator power......and eventually the batteries would discharge from any loads connected to them directly (parasitic loads like propane gas detector etc). The other observation is your +12vdc terminals (front in battery pictures) seem to be connected to the top terminals of the two HI Amp DC breakers.....one looks like 100 amps; can’t see the other. These typically connect to the generator starter motor; the hydraulic pump motor for your jacks; or possibly inverter. Note the two +12vdc battery terminals are cabled together; and I would expect the two -12vdc battery terminals are also tied together and then connected to chassis for your DC ground (the batteries are connected in parallel to provide same voltage, but then they can supply current for longer periods to the coach loads).


If you had a voltmeter, I would check for any 12vdc on the loose cable when on shore power. Make sure the 50 amp DC breaker is closed (not tripped) and use/store is on. It might be possible that the use/store latch relay gets its “on/off” control voltage via the loose cable +12vdc cable connection. So no connection, no latching relay operation. If you don't hear the latch relay operate and release, you likely won’t get any voltage reading on the loose cable. I am attaching a basic RV battery DC schematic which is generic only and probably does not match your coach exactly. On the right side it shows how the converter fuse panel connects through the latch relay and 50 amp breaker to the coach batteries. As I said previously,, if you are not electrically experienced call an RV tech who knows what they are doing.....the money they charge is worth it if you and your RV remain safe and sound.

[cavie]

GFI is 120 volts does NOT come into play here.

[reminckv]

First, let me say that Cavie and javelin are far more experienced with these electrical issues so take what I say with a grain of salt and I suggest paying close attention to what they say. But, to add to your learning curve, I'll add an observation.

I see, in the lower left hand corner of your pic of behind the batteries what looks like the battery isolation relay or "Trombetta" relay. I won't go into details on it's function, but will say that once everything is connected properly, this relay will need to work correctly for your coach batteries to be charged correctly. There is very likely a BIRD (bi-directional isolator relay delay) in your coach, maybe behind the batteries too. The yellow wire going to the coil of that relay originates at the BIRD. If you get to the point of wanting to learn more about that system, you can search "Another Battery Isolator Relay Question" which is a thread that I started and contains some links and other info.

[Islandsmith]

Hi Tullywork,
On my 2018 34J that cable runs to the positive terminal in the inner battery. My batteries are installed backward from yours - the positive terminals are in the back of the bay. When I replaced my batteries I took some colored trailer wiring tape and put a different color on each cable end depending on where it was connected. That and some pictures made it much easier.

Here is a picture of that cable connected to my inner battery positive terminal.

[tullywork]

Thanks very much everyone, this has all been extremely helpful and insightful! I didn't get to the RV today, but plan a visit tomorrow. I also spoke to my father-in-law who's a mechanic who gave me some instructions and safety tips for the batteries. Hopefully I'll be able to get a better idea on what I'm dealing with tomorrow. Will update everyone (or likely have more questions) after.

Thanks again!

[cavie]

The gray and black box in the picture is an Inverter. It changes 12 volts to 120 volts. That may very well be the loose cable at the batteries. See if you can follow the Romex coming out the right side and see what outlets it powers. Most likely the fridge and/or TV outlets.

12 volts does not power the Converter. 120 volts does and it is just a charger that runs your 12 volt system and charges your batteries.

It's obvious that this problem didn't "Just Happen" on the last trip because that cable didn't "Just Happen" to fall off.

Contact Thor with you Vin# and request a wiring schmatic.

[Islandsmith]

What year is your 34J? The wiring mess under the master bed looks like that (it's on my list of to-do's to clean it up) but my inverter is mounted in one of the outboard cargo bins. Amazing how different they can be.

[tullywork]

@Islandsmith my 34J is a 2015, my inverter is also in the second (including the small/long cargo bin) rear most cargo bin on the slide side.

Thanks again everyone, especially @javelin for the generic schematic. Turns out the loose wire was the issue, I attached it to a positive terminal and we're back in business!

The House has basic power (lights/nav) when entering and everything is working as expected. Here's what I think happened: the original house batteries were failing (low voltage) which caused the original issues with the converter not providing sufficient power to the lights/house as expected, then when I had the mechanic swap the bad batteries for good ones, they overlooked connecting the connection for the the converter as shown in the schematic, which made it seem like the same issue persisted, but really it was a different issue with the same symptoms.

Connecting that 'lose' cable to the positive terminal seems to fix the issues i was experiencing.

Thanks again to everyone that responded! I'm really looking forward to being part of this community!
-T

[cgeace29.3]

I had similar issues
Your battery’s are to low on charge
Take your batteries out and charge them
Be shure to label the wires and where they connect before disconnecting with tape
May take a few days to charge them to 13v
Put them back
Put disconnect switch on use
You will be fine
Remember when hooked up to power switch in use position or battery won’t charge
Only put switch in disconnect when in storage

[wbrodmerkel]

2017 ace 27.2
3 electrical questions.
Left my mh at a service shop. It sat for 4 days. Nothing was left on.Not plugged in. Both house batteries dead as well as starting battery. Jumped, charged fine w/ generator. charges fine with shore power. 1.Noticed that battery disconnect does NOTHING. everything works the same either position. run or store. Wired wrong from factory or failed part?
2. What should I look for as far as why drawing current while nothing is on?
3. Also , is the wiring correct that the start battery would also be drawn down?
thank you

[javelin]

1. The latching relay can fail in the on or off position. Sounds like yours failed in the “on” position. With no shore or gen and engine not running, assuming your house batteries are charged, can you still turn on coach DC lights and fans/water pump? If yes then the use/store latch relay is on and apparently is not turning off when you go to store position. You should hear the relay operate and release when use/store is operated.

2. There are parasitic loads in most coaches that draw current from the house batteries all the time and are not necessarily turned off by the use/store latch relay in store position. Like propane and CO detector(s) as an example. Many RVers use manual battery disconnect switches located right on the appropriate battery string terminal(s)......so they are totally isolated when you want them to be.
3. Good question. Depending on the battery charging control system your coach has there is typically an interconnect (or emergency start) relay that can also be operated by the battery control system to connect house and chassis batteries together.....for example when driving the alternator can be used to charge both sets of batteries; or when on shore, the converter can be used to charge both sets of batteries. So unless you also have some parasitic loads on the chassis battery there may be something wrong with your emergency start relay or the battery control system. You definitely want to check this out ASAP.



Last comment, if your battery strings were not fully charged when the shop got your coach they would not last long depending on the loads left on them.....or possible shop workers' using lights etc for their required work.

[sanjaun2]

lots of great help you are getting here, Please do me a huge favor, Wrap that lose terminal with electrical tape until you figure out where it goes! If it has power on it, it will short out if it hits anything metal and can cause a fire.

[wbrodmerkel]

Following my questions about the battery disconect, I located the latching relay under the master bed. following the troubleshooting procedure for the intellitec battery disconect relay 01-00055-002 (http://techsupport.pdxrvwholesale.co...-00055-000.pdf ) I determined that I had a faulty relay stuck in the in use position. Ordered a new one thru rvpartscenter.com .cheap at $39. I will let everone know how it went. I thank you all. Next step is to determine if there is a problem with the emergency start relay or battery control system.

[Islandsmith]

Originally Posted by tullywork

@Islandsmith my 34J is a 2015, my inverter is also in the second (including the small/long cargo bin) rear most cargo bin on the slide side. (snip)

-T

I may be confused but isn't that your inverter pictured under your bed where the converter is also located?