Battery mode Switch?

[Damon T]

So my 2007 Itasca Cambria has this box in the passenger side exterior storage compartment under the sink area. The battery mode switch fuse (is it a fuse?) is pushed all the way in. The rest move in and out. I’ve been having issues keeping house batteries charged. I checked the house battery yesterday with voltmeter and it seemed to be getting juice from alternator , generator and shore power so maybe I just haven’t been maintaining it well and parasitic loads. But what does this switch do?

[Damon T]

I pulled the house battery to top off and clean connections prior to checking the battery mode switch so maybe that’s why it won’t reset ? Will find out soon.

[Morich]

That label may be cofusing you a bit?
Those are pop out type breakers and they should stick out something like 1/4 inch when they trip. Better than fuses as you CAN push them back in to reset.

The mode solenoid and battery disconnect relay are behind those breakers and that can make it a trip to get to the solenoid if it fails! The mode solenoid seems to be one of those things that arequicker to fail than lots of things because the operate and arc every time we start the engine as that connect coach and start batteries together. Lots of use, lots of arcing burning that lerads to the contacts getting pitted/ corroded so they fail to make good contact and the coach batteries don't charge while the engine is running!

We don't get the great new diagrams for pre 2010 that we do for later but this is an area that is pretty common across many of the Winnebago line so good chance this is what yours looks like inside?

Click these to get a better view and they ARE NOT exact for your years but so generic, I expect you would find this.

The drawing overview is that the two sets of batteries both have cables to the mode solenoid, there is a control wire (LR) that brings battery from either the dash switch or when we have ignition on that makes the contacts in the solenoid connect the two together!

[Bones2003]

Damon, that is not a switch. It is a circuit breaker as Richard says above in his post. That breaker apparently protects the Battery Mode Switch which is usually mounted somewhere on the dashboard. The Battery Mode Switch is generally a momentary type switch that allows you to start your RV from the house battery if your chassis battery is dead. It is also called a Battery [EDIT]Boost Switch. Doesn't seem like it would be related to your problem but I guess anything is possible.

Are your house batteries dying while in storage? Do you use the Battery Disconnect Switch (usually located by the step well.) How old are your batteries?

[Damon T]

Thx so much for info and replies. I think I haven’t always used the battery disconnect switch properly not to mention turning it on when driving to recharge. Still lots to learn after several years of ownership. The 6amp breaker for battery lmode switch seems stuck in not out so that’s weird cuz all the rest of them move freely when pushed One battery is prob 2 plus years old group 24 deep cycle RV marine. It’s partner totally ran out of water and died so yeah learning about maintenance and not keeping plugged in continuously for long periods without either turning off batteries or disconnecting them. I think I cooked the other.

[Morich]

Sorry about that! Bones has pointed out what I missed about your question!
I had not looked close enough to spot the breaker label!

But it does relate to one of the things that is often missed when we first get into dealing with the RV batteries. The battery disconnect switch DOES NOT disconnect ALL the drains on the battery. It leaves what Winnebago feels are important safety items still working. CO and propane detectors, steps, etc?

If we trace down the feeds to these breakers we see that panel actually has three seperate buss bars that are fed from different places and whether they are powered or not depends some on the position of the disconnect relay.

One big item to keep in mind when looking at these drawings is that the breakers are shown from the backside, making it important to turn the panel around mentally if you are looking from the front! The 6 amp that is second from right from the front is second from left on the drawing of the back?

But then tracing the power from the source, the breakers I highlighted in red (KKG) are hot all the time but those on the green group (KKF)get power ONLY when the battery disconnect is on (passing current?)

Lots of small details in that area to get a handle on if the batteries are doing weird things, like running down when you thought you had them all disconnected?

[Morich]

If still looking at this question there may be something easy to help sort out what is going on. The breaker may just be a bit odd looking and still working okay but a test may get you an answer.
I think we are right in saying that the power to the boost or aux switch on the dash comes through that breaker,so if we try the switch in a quiet place and time, we can often hear the big old solenoid go "thunk" as it is a big, half dollar sixed hunk of metal that moves to close the contacts on the solenoid. Worst case, if the place is noisy, if you put your hand in andfeelof the solenoid while csomebody else pushes the switch, you can almost certainly feel it!

But if you are a person who has a meter, there may be an easy alternate.
What that solenoid does is connect coach and start batteries together, like if we want to do a jump start when the start battery is a little too weak.

So if you test the voltage on the two sets of batteries, most likely one will be higher than the other. IF we push the boost switch and the batteries then read much the same on each, we can say they are connected and the breaker, switch, and solenoid are all doing it right!
Keep in mind the switch is a momentary type and only connects while we push it. It is NOT the type that turns on/off.

Also when the RV engine is running the solenoid should connect them to do the charging while we drive.

Tricky little system that takes some time to get in mind.

[cbeierl]

Here's a link to all of the Wiring Diagrams for your coach. The Chassis Electrical Box Assembly diagram and Body, 12 Volt Wiring Diagram may be of particular use in this instance.

[cbeierl]

You may also find the Wiring Identification Guide and Wiring Diagram Help useful in interpreting the wiring and wiring diagrams.

[Damon T]

Would I have the meter hooked up to the chassis battery while someone hits the boost button? That seems to make sense. There is definitely a clunk / click when I hit the battery disconnect switch and I’m pretty sure when I hit the boost too.

[Morich]

Originally Posted by Damon T

Would I have the meter hooked up to the chassis battery while someone hits the boost button? That seems to make sense. There is definitely a clunk / click when I hit the battery disconnect switch and I’m pretty sure when I hit the boost too.

Some depends on situation.
If the RV is plugged into shore power, the converter should be working to charge the coach batteries and that would make you see near 13-14 volts at the post and the start battery would be around 12.8 if in good shape and fully charged as lead acid batteries will only hold that voltage after they settle. Anything higher is just the "surface charge" from charging and will settle after a few hours.
So if plugged in and you see higher on the coach and lower on the start, looking at the start battery while the button is pushed will show that start battery reading go higher pretty quick (seconds/ minutes?) as they connect together.

But if not handy to plug in,you can get the same idea that the solenoid is working by going the other way. If the coach batteries are down a bit like 12.0 or lower, not plugged into power and you start the RV engine, that connects them together also and makes the coach voltage jump up!
One way to know you are looking at the charge comming out of the engine alternator is to watch the voltage and see ifit goes higher as you rev the engine a bit. The voltage comming from the engine alternator will go up and down with speeding up the motor, while the voltage from the converter and being plugged in will only change slowly. So if you are looking a t a pretty steady voltage that doesn't change when you speed up the engine, you are not seeing the alternator charging at that point.

It's kind of a multi-function area. One way it connects them while we drive to recharge the coach batteries a little as we drive OR it can connect them to give a weak start battery a boost by pushing the dash switch.

Most of the time the two battery groups will be slightlly different charge, so if we look at one and see itlower and then do one of the two things, the switch or start the engine, we expect to see near the same voltage on both as they are connected together!

One big point to keep in mind is that the voltage in batteries is from a chemical reaction and that is a SLOOOW process, like hours! So if you look at a battery that has just been getting charged it may show really good like 13 volts but that is just a false reading and will go away when the chemicals get stable again.

[powercat_ras]

I had a 2008 Cambria at one time. The coach batteries would run down to 50 % in about a week if I left the coach battery disconnect switch on without any power source connected and/or without charging from the engine's alternator. The propane detector, radio battery backup, thermostat, refrigerator control board, and step control board are the loads you can't switch off.

I suggest you get a portable solar panel with 12 volt charge controller like this: DOKIO 110 Watt Portable Foldable Solar Panel Kit ( 21 x 28 inch, 5.9 lbs )

It's a little bit bigger than the minimum you could get by with, but I have used DOKIO to help many of my RV buddies maintain their batteries with solar and this has given me great results. Me and my buddies boondock and I generally recommend the DOKIO like this with 4 solar panels that puts out twice the power, if you boondock that's the one to get. If you just want to maintain your batteries without plugging in or running the generator, this one will do it. If you boondock, the most bang for your buck is to change all the light bulbs you run a lot after dark with LEDs. The one's you don't use much, don't bother.

There are also versions of this that come with a box with LiFe batteries that outputs either 120 VAC or 12 VDC, plus USB ports for charging gadgets and phones, for more cost. They are generally called portable solar generators.

[Damon T]

Powercat
Oh thanks so much! That was the next thing I was trying to figure out. I like that it’s a complete setup. I saw on that solenoid board I sent a pic of it had an empty spot for some kinda solar setup but this looks nice and simple to maintain the batteries.

[Damon T]

Btw I just ordered 2 of those 100 AH AGM WEIZE batteries. Looking forward to getting this rig more independent of shore power. At least for a few days or more with solar or generator to recharge.

[Damon T]

Hi, on the Dokio solar power kits are the charge controllers fine for recharging AGM batteries? I noticed one online reviewer said to trash the controller but you seem to have a lot of experience with them. I’m lookin at either the 160 or 220 W kit to help with boondocking.