Coach Batteries and Storage

[HoosierB]

As this is my first "winter storage" for the Chinook, most of what I have read says switching the COACH BATTERIES to the "STORE" position should be all that's required. The rig will be stored in a climate controlled facility until the end of March, so no real winterizing should be necessary. Is adding a disconnect throw switch on each coach battery terminal additional preventive maintenance or not really needed? Note when replying: I am auto electronics challenged.

[Blue~Go]

Hi HoosierB,

I'm going to assume you have flooded cell batteries (typically this means they have the caps you can open and check the water in them). So, here is what I would do.

1) Check the water level in the batteries; top up if necessary.
2) Charge the batteries fully. It's best if they are fully charged going into storage (more important if they will be in freezing temperatures, but still good practice even if not).
3) Flip the switch to "Store."

Now, the next thing depends....

Although I don't have this system anymore, from what I have read, "Store" doesn't disconnect everything. I guess there were certain things Chinook thought should be left "on." I think the detectors is one of them, and it sounds like maybe the electric step is too (I have a manual step). Of course these things can put a draw on the batteries. Detectors are all well and good, but you presumably won't be in the rig to hear them (and too, I'd think you'd have the propane shut off).

If you do want to be sure all loads are disconnected, there are a couple of ways to go about it.

1) You can remove a cable from the battery post (typically the positive). You'd want this to be the cable that leads from the closest battery to the rig, so both batteries are included. The separator should theoretically keep the start and house batteries separated, but you could also disconnect the other cable on the house battery that leads to the separator (and thence to the start battery). Or you could (also) disconnect the cable from the start battery.

2) You can put in a battery switch, something like the Blue Sea 6006. This is actually a recommended practice on boats, and to my mind a good idea on RV's (regardless of storage). This allows you to swiftly and positively disconnect the batteries from everything. It would only take one switch, and that switch would go in the cable that leads from the battery bank to the loads/charger (no matter how many house batteries are on the other side of it). The store button mostly does this, but just not completely (and not super close to the batteries). Even with this switch, you might want to disconnect a start battery cable, but that's separate from "house" stuff.

You may find the "store" button is good enough, but you won't know for sure if you are not keeping an eye on the batteries. The detectors don't draw much (although for some odd reason some people's seem to draw more? Mine were a very small load), but on the other hand you aren't putting anything back, and even a small load is a fair bit when added up over time.

Oh, one other thing you could do: Put the coach switch in "store" position, and then try turning anything and everything on. Check detectors, the step, everything. Then you will know what is not disconnected with the store button. Too, then perhaps you could just pull the individual fuses on those items from the fuse panel. If you don't feel like messing around with battery cables.

But removing battery cables is fairly easy and does the job for storage.

If anything doesn't make sense, just re-post. If you are going to disconnect the cables, I could post photos of what they look like on my rig. Also, I imagine some other members will have good suggestions, and perhaps pick up on anything I missed.

[HoosierB]

Thanks, Blue-Go!
So, by switching to "STORE" and a simple disconnect of the last battery (closest to the house), I should be good to go. Any "visual aids" to show a recommended master switch installation would be helpful.
BTW: new house bats were installed by Duncan RV a few weeks ago. I should have had them do a master switch at that time, oh well. My rig does not have electric steps.

[Blue~Go]

Thanks, Blue-Go!
So, by switching to "STORE" and a simple disconnect of the last battery (closest to the house), I should be good to go.

I think so. Actually, at that point you don't even need to switch to "store," but why not.

The only other thing that could possibly draw down the house battery, would be if the Sure Power combiner (this is what allows your Ford alternator to charge your RV house bank) were to somehow fail and stay connected. Then any phantom loads that might be on the start battery (Ford system/radio/etc.) could theoretically get to your house bank.

But normally, that Sure Power should disconnect when the banks aren't being charged. I know they can fail, but not even sure if they would fail "connected" anyway. A way around that would be to also pull a cable on the start battery. Might not be a bad idea anyway if you have any potential phantom loads on the start battery. This will remove your radio presets (until you put them back) because the radio memory will not be powered, and I have heard that the transmission may have to "relearn" your driving style (but I have never noticed that, and I've had my start battery disconnected for weeks).

So the upshot is that if it were me, and absent real, honest-to-goodness, disconnects-everything switches (and presuming you are not going to be charging the batteries while in storage), I would disconnect a cable between the "closest" [electrically] house battery to the loads, and I would also disconnect the start battery. Then nothing can get to your batteries. The rig will then be "dead," but if you are in disconnected storage (i.e. not running charger and no solar power) then there is nothing you'd be running anyway.

Any "visual aids" to show a recommended master switch installation would be helpful.

Personally, I would go with a Blue Sea as mentioned above. There are "remote controlled" switches (which is basically what the "store" button is), but there is nothing like a big red mechanical switch, in my opinion. There are two places you could put one.

1) In the cable leading from the "closest" house battery to the rest of the rig - this might be in the battery compartment itself. This is best from a safety perspective (as there is the least amount of energized wire when the switch is off), but you'd have to get into the compartment to turn it on and off. This may not be an issue, but just mentioning.

2) Inside the rig, near the LVD but before it, electrically. This would not be as good to my mind for a few reasons. The one advantage is that you can work it from inside the rig, but I'm not sure I see that as a huge plus, since it's not like you are going to put the rig to bed for storage without ever stepping outside. And it leaves a few feet of wire still energized.

Can you post a photo of your battery compartment? The wires coming off the batteries, if it's like mine was originally, should exit the compartment wall near the compartment door on the forward (toward the engine wall) side, up near the "roof."

If we figure out how you want to do it, and you need a small jumper wire with lugs on the ends, I can make one up and send it to you.

Basically what you are looking to do is to remove the wire that leads from the rig to the "first" house battery, and instead put it on one of the lugs of a switch. Then a short jumper will go from that switch to the house battery where the wire you just took off used to go. So you are "inserting" a switch into the line. I don't have my batteries arranged in stock configuration anymore (I have a "mockup" setup right now, albeit it's properly wired), but I'll take a photo of my switch, just to show you how they look.

There is one optional "extra credit" thing you could do, but if it seems like too much, just never mind, and you won't be any worse off than you were before.

So, the wires coming off your house bank are basically big, energized hunks of metal, with a large potential amount of power that could be unleashed (the contents of your batteries). If a short or etc. happens (wire chafes through, etc.), then this power is just waiting to pounce on anything in its way. Hence we have over-current protection (fuses and breakers). Any wire that runs between the batteries and the fuse(s) is not protected. Hence we like to put the fuse as close to the battery as possible. You know, hang on. Let's see photos of how your battery compartment is wired up first before I blather on. It may not be just the same as mine, and I can see that in later years Chinook made some of the improvement I was going to suggest. By waiting, I can confuse you specifically instead of generally/wrongly

I'll come back with a few photos just to show some stuff.

Okay, here are just a few photos semi-related to what we are talking about. In this first one, I am lying on the ground with my feet sticking out from under the rig on the driver's side, and my head toward the passenger side, looking up. The battery box is to the left. The rear "wall" of the cab is to my right. Just gives an idea of how the battery wiring runs when it leaves the battery box. 1999 vintage, with two original house batteries in slide out tray. The only thing not as stock is that the little white fiberglass perforated cover is removed from the breakers (it normally covers them).

Here is a photo of my current "working mock up" electrical control area. This is under the couch. Not that you would copy this, but it shows the general idea of a switch. If you are of the mindset, you can follow along just to get a feel for it (or not! if this is TMI just ignore).

So, the batteries are behind the wooden box, directly behind these components. The positive wire off of the "last" battery, comes around on the left (just out of sight) and immediately goes to that first thing on the left, which is a Class T fuse. I needed Class T fuse because the fuse/holder/design needs to be able to handle the potential 12,801 amps that is the "short circuit rating" for these batteries. The Class T can handle up to 20,000 amps. The usual battery type fuse I recommend (and which I do have on the start battery) can only handle up to 10,000 amps (which is likely fine for your bank).

So as you see, there are two red cables coming off the Class T fuse, leading to two switches. The red switch is the "Main house battery disconnect." This disconnects ALL loads from the batteries. It also isolates the batteries from being able to "send" power to anywhere. This is the switch labeled "DC Main." As you can see, there is another red cable coming out the right hand side of the switch leading to a fuse block. This is my "working mockup" main fuse block. This is the equivalent of the wire leading from your batteries up to the LVD that's just ahead of the couch near the floor on the pillar. The wires coming out the bottom of the fuse block go to things like generator start, solar controller, and the "brown box" fuse block that Chinook put in. The fuse block has appropriate fuses but they are behind the cover where you can't see them. This is a fuse block I had lying around from a boat project - not the one I will ultimately use.

Above the red switch is a black switch labeled "Alt disconnect." This switch takes the place of the Surepower automatic combiner that Chinook had under the hood. I don't need to combine very often because I have enough solar power. Also the alternator output is not as "smart" as my solar charger (or as the smart shorepower charger), so I'd rather not have it in the mix unless I really need it. Thus it's normally off. The wire going off the top of the black switch is the one that goes to the start battery, so it's the equivalent of the one labeled as such on the first photo, where I'm lying under the rig.

Again, not that you are going to duplicate this (even I'm not keeping it like this long-term), but just to give you an idea of how the switches look, etc.

Now, I'm interested to see what your battery box and the wiring in there looks like, if you want to post a photo. (But rest assured that for now you can just disconnect battery cables for storing rig.)

[HoosierB]

Photos of my '01 battery tray.

[Blue~Go]

Just wanted to let you know that I'm on my way out for a few hours, but I did take a quick look. I think you may want to rearrange a few of those lines. I see a couple of issues, I believe. But I'll look more closely later and write back.

One question: Where do the wires exit the battery box? I can see they are not where mine were. Are they still on the forward side of the box (toward cab) but just at the rear?

[Blue~Go]

Okay, so.... I think I see a couple of misconnections on your batteries. I may be seeing things wrongly, as I'm not there, but I'll try to describe what I think I'm seeing, and then you can look in reality and let me know if it's different (and then we can go from there).

So first of all, I'm assuming (but correct if I'm wrong) that those are two 12-volt batteries, connected in parallel. (This was the original Chinook setup, unless you have gone to two 6-volt batteries in series, but I'm doubting that.)

If that's the case, you want them to be as "even" as possible. You don't want more of the draw coming from one battery, and less from the other. That would be like the person at the front of the class always being called on, while the fellow in back just doodles in his notebook. So, there is a "best" way to hook things up. What you want to do is have the negative wire going one way, and the positive going the other. Here is a drawing of good vs. not so good that shows it. There are four batteries in this drawing, but you can just picture the same thing with your two. This is for batteries in parallel (in other words, this presumes you have two 12 volt batteries supplying a 12-volt system and you are "adding them together" to make a larger 12-volt battery bank - unless you have changed Chinook's original premise, that should be what you are doing now).

Here is the correct way:

Here is the not-so-good way:

What I think I see on your bank is a kind of modified not-so-good way. At least, here is what I think I am seeing. Orange is positive and blue is negative.

So that doesn't look like any of the diagrams, and you have positive wires going off in two directions. I don't see how that can be good! What I think is that you should first choose which of two positive posts it would be most convenient to have all the positive wires (the ones that lead away from the batteries) come off of. Likely the right one, but it doesn't matter, so whichever one would make them "fold in" better when you move the tray in and out. Then put all the incoming/outgoing positive wires on that post. (A bus bar or power post would be tidier, but you are allowed to have up to four conductors on a post even by ABYC guidelines, so you can do it.)

Next the incoming/outgoing negative wire goes on the negative post on the OPPOSITE battery to the one you just put the positive wires on. That gives you the "better way" flow shown above.

Next you just put the jumpers between the batteries. The negative jumper goes from the negative post that has the incoming negative wires on it to the other negative post. And the positive jumper wire goes from the positive post that has all the incoming wires on it to the other positive post. Okay on to next post so I can put a fourth photo in....

[Blue~Go]

So then it would look something like this. If I've drawn it reasonably, it should be clear how it looks like the "better" hookup, but is using the wires you have already.

Does this make sense the way I've shown it. I know, side issue from your original question, but it's important to have them hooked up correctly.

[HoosierB]

I think I get it. Like your last diagram, it would appear that my left battery should have the neg lead attached to it (its now on the right battery). Keeping both short jumpers in place, the extra pos lead should be ganged with the other two leads on the right battery, which would give that post a total of 3 connections plus the short jumper.

[Blue~Go]

I think I get it. Like your last diagram, it would appear that my left battery should have the neg lead attached to it (its now on the right battery). Keeping both short jumpers in place, the extra pos lead should be ganged with the other two leads on the right battery, which would give that post a total of 3 connections plus the short jumper.

Yes that's it. Although the whole kit and caboodle could also go the opposite way. To me the decision point is which side is most convenient to have that big group of positive wires coming off in. So it meshes with the tray sliding in and out. The negative being a single cable is not as much to manage. But presuming the positives are happy coming off the right side (as photographed) then yep.

Right now your positive wires are having an identity crisis! They don't know whether they are coming or going.

You know, I was just sitting here scratching my head wondering why you have three large positive cables on your house bank, whereas I only had two (one from start battery; one leading to LVD and thence brown box). But, Aha!, I bet the third one is your generator starter supply wire (which on my era rig, went to the start battery). The fourth (tiny) wire is from the solar controller (or at least was on my rig). That's the one with the small inline fuse.

Do you have the same thing going on underneath as I showed on my rig? That is, cables leading in generally the same formation, and some fuses inside a white fiberglass "cup" with holes in the bottom? Just curious.

If you still want to put a switch in the positive line, then you can consider where you would mount it before deciding which side to run the positives off of your batteries. I can't see what happens to your cables as they pass through the compartment wall. You'd be adding the switch to only one of the positive cables. It would be the one that goes to the main fuse (in the white cup) and thence to the LVD, and thence to the brown box. So for example, maybe you could mount the switch on the side of the battery compartment above the sliding tray, lead the wire in, to the switch, then from the switch to the battery post. If it would all still slide okay (?).

Normally, you have the fuse first, then the switch, but since your fuses (if they are in the white cup) are way under the rig, I'd put the switch in the battery tray area where you can reach it. You could also change to a MRBF which mounts right on the battery post and protects every inch of the wire, if you have an inch or so of height to play with.

OTOH, if you are "done" with this sort of thing now, and just want to get the rig in storage, taking the battery cable(s) off is always an option. Power can't drain through air!