Coach Battery connect/disconnect issue

[Nal]

The problem in our 2010 Itasta Ellipse is when you park in storage, batteries are charged, then we shutoff shore power, and disconnect coach batteries, if it sits for two or three weeks the house battery won't come back on and when we plug back into shore power, the house battery switch won't come back on and turn shore power on only micro/tv's power up, but invertor, lights etc, won't come back on unless you put a charger at 2 amps for about a minute on house batteries, then switch works and invertor and lights etc come on and house batteries show 12.3? and will work as normal...so not sure what's wrong? thanks for any help..

[Nal]

solenoid maybe ?

[Morich]

First guess is not always the best without actually looking at the specific drawings for your Rv, but this is what appears to happen. Assuming you mean disconnect batteries using the disconnect switch, that is likely fooling you as that switch only disconnects part of the load and leaves several safety items like CO and propane detectors powered. Those small items do draing the coach batteries and when you comeback and try to turn the coach batteries back on,the relay which connects/disconnects the batteries has to have battery power to move!
If you look at the disconnect switch carefully, it is a type which rocks one way or the other momentarily but doesn't actually stay flipped/moved when you release it. This momentary switch does just give a momentary burst of power feeding the relay and then that relay has a magnetic gizmo which "latches" tostay in the last position.
That means when you hit the switch to turn on and there is little power in the battery, the relay tied to that switch which is what actually does the work, just sets there in the last position and you have ntactually reconnected the power!

Hope all that makes sense?

But to further confuse, the TV and AC power things do not work through this disconnect/relay setup but come straight from the AC power and those as well as outlets will still work when plugged in!

Normally when plugged in and the disconnect switch is closed AC powers comes from the cord, the the disconnectswitch and relay to the converter and the coach batteries get charged, but with the relay still open, that charge doesn't happen. Only when you put a charger on the batteries and they get enough charge to move the relay, THEN turning the switch on, the relay gets enough power to move and things come alive!

I would guess that you do not actually have any equipment failure but more of part of the confusing way things work on the RV.

Why would it be designed this way? If there was not a latching relay, powerwould be needed full time to keep the battery connected and this would quickly drain the batteries while we were camped without being plugged into power! So it is a good system but needs study to understand more what it requires.

Two solutions may help.
One is to use a stand alone charger to keep the coach batteries charged while turning off the coach battery disconnect. Keep in mind this doesn't cover the start battery potentialy running down, only the ones connected to the charger.

Two is putting a simple battery disconnect switch on the negative side of the coach battteries as a way to fully open the path. This does fully disconnect the load but also has the factor of also disconnecting the detectors for CO and propane, so leaves a small bitof hazard there to consider. I do not consider this a big hazard as nobody is sleeping or staying in the RV while the safety items are shut down.
Personal choice to think about!

[TerryMA]

Which way will charge a battery faster (Micro Minnie 2106 FSB )
1. Jumpers directly to battery (isolated)
2. 7 way plugged in vehicle running ( battery isolated)
3. 7 way plugged in vehicle running (battery NOT isolated) but being charged from the house system inverter)

[Nal]

Richard thanks for the quick response sounds like our issue, so what is the best alternative leaving the coach plugged in all the time, a trickle charger or a battery disconnect?

[Morich]

I suspect there is not a mechanical problem but more due tothe confusing aspects of RV!

I did a snip of the drawings for the 2009 model as the 2010 and newer are not provided online but I would guess they are very near the same as almost standard on Winnebago.

You mentioned the solenoid but I think not a problem as it is what connects coach batteries together with start batteries at specific times. I showed this with green for start and redfor coach. I suspect that is okay.

Looking at the red on this snip, note how it comes from the coach batteries to the solenoidthen a second cable on the same post there goes to the battery disconnect relay. This doesn't require the aux solenoid to be closed as the two cabels are on the same post. The solenoid only connects the two sides, (red and green) together when that solenoid operates. solenoid not involved in current problem?

Once that red trace gets to the disconnect relay the power only goes through IF the relay is closed, then on to the disconnect switch which controls that relay! I suspect that is where things go wrong as the relay doesn't get power from the switch if the switch doesn't get power from the coach batteries!

What I see happening is that the disconnect doesn't actually disconnect ALL the battety drainn but leaves the safety equipment on the little 6 ampcircuit marked in blue still CONNECTED to the coach batteries and that runs them down.

When you come back to connect, there is little to no power in the coach batteries and the switch has none to past back to the relay on the control wires LH and LG.

The tricky part is that this relay is a "latching" relay that stays latched in the last positonwe had it when we turn loose of the momentary switch which we call the disocnnect switch. Notice this switch feels different and doesn't click? This is because they want ti drawingpower only while we press it to avoid using power full time to run the batteries down when camped without plugged into power!

What I see happens:
1. The drains still connected when you turn the disconnectoff, do slowly draing thecoach batteries and that means when you store and come back, flipping the switch has no power, so the relay doesn't move to close the power to the rest of the coach items.

AC power to thingslike the AC, microwave, and many outletsdoesn't work through this system, so they work.

When you finally put some power on with a charger, the batteries do get up high enough to let the switch tell the relay to move and it does finally connect them and part of that sytem is the converter which workstocharge the batteries!

In a confusing way it is like your house might work. You normally have power coming in but if there is a power failure, turning on the switch to the TV doesn't work, even though the switch and TV are okay. They only work when we hook up a generator to the house to start the chain?

Click this drawing to get a better view of what I think is happening?

[Morich]

Originally Posted by Nal

Richard thanks for the quick response sounds like our issue, so what is the best alternative leaving the coach plugged in all the time, a trickle charger or a battery disconnect?

This varies with what we each have in our life!
Various problems in each case, some matter more to each of us at different times.

Leaving plugged in full time has some problems in that the converters, especially older, do not have a really fine setup to put a higher charge on at first to get batteries charged quick and then stages where it drop the charge voltage as the battery nears fully charged. This can sometimes heat the battery and make it boil water and acid to go dry while we are not looking. Going dry is a definite battery killer, so should not be letting that happen!
Better, newer electronics have more stages and better controls to charge fast and then back off to a "float" voltage. And knowing what your RV converter has is a big question.

A trickle charger can be good but that also needs to have some attention as it can still use more water than expected and we need to watch until we know how it works out. Sometimes that is hard when the RV is not at the house?

Also be aware that the charging the coach doesn't take care of the start battery if we don't add something like a Trik-L-Start, etc to let some go to that battery, too.

A battery totally disconnected can hold a charge better but even at best, every battery has a certain amount of "self-discharge" and needs attention at times.

Bottom line is they are a pain and how we each need to deal with it depends on things like how cold and how dry, how busy and how much time we are willing to spend, where the RV is parked, how long between use and all kinds of small points.

Best I've figured out is that it costs quite a bit to keep one and even more to buy another after I sell the one I didn't need!