what does battery disconnect switch not disconnect?

[CHICKDOE]

again, thanks to all the replies. I've learned a bit. somebody posted that you can get custom made battery cable and I have been researching these. they will make it very simple to install a true disconnect. can I ask one more question. i'm thinking of a knife style disconnect switch installed in the negative battery lead. do you see any problem with this. the issue would be that the knife and contacts are exposed. but since it is the negative lead even if something touched it erroneously, it would be at the same voltage as the chassis so there would not be any short circuit. or should it the rotary style switch that has the contact posts shielded?

[bikendan]

Since my trailer didn't have a factory disconnect switch, I added one on the battery post.
That way everything is disconnected except the power jack.
Cost me about $6.

[WolfWhistle]

Originally Posted by CHICKDOE

to all, just thought I would give an update. I spent the morning trying to find everything that will run even when the battery is 'disconnected' via the factory installed disconnect switch. here's what I found that I believe are always on and drawing battery current:

then there are several lights that will operate with the batteries 'disconnected' but they should not be drawing current as they are controlled by individual on/off switches. of course if you left one on by mistake it would draw power while disconnected.

so yes, my batteries do have a load on them and get drained even when 'disconnected'.

There has to be a wiring issue if lights are working with the battery disconnect switch (BCO) in the off position. I would have to check that out. The way mine was: B+ from battery down to the front of the trailer; through 30A breaker to the copper bus, which allows via other breaker to feed the hot to the generator, and though another breaker to the slide controller. From the 30A to the cutoff switch via a #2AWG wire and back to the bus where it then feeds the WFCO panel (where the converter is located). The BCO off killed power to the fuses in the WFCO panel, unless I was on shore power; since the converter would then power those fuses even if the BCO is off, but would not charge the batteries. My BCO functioned correctly. I remember helping a member figure out why his BCO didn't work; someone had strapped out the BCO wiring at that bus location, effectively eliminating it.
WW

[BBQGUY]

On my Puma 5er, added a battery disconnect switch positive side, positive buss bar (generator, inverter, charger) main resettable fuse for those items that were connected directly to the battery and moved them to a new fuse box for easy access. Added a compartment light while I was at it.

[WolfWhistle]

Here's what I have for a battery cut off switch. Its a marine product and cost around $35; not counting the cost of custom cabling. It allows me to disconnect either one string, or the other, to disconnect all, or to have all batteries on-line. I abandoned the factory BCO, since with my inverter / charger it is no longer a viable option.

You might notice its on the negative or ground side, primarily because of convenience.

A simpler solution for simpler systems (one proposed on this post) is a simple automotive disconnect directly on the battery.

Remember before storage and before disconnecting batteries to have them fully charged. Then, remember before towing to reconnect the switch.
WW

[#1BAMAFan]

As I have said in a couple of other forums, We are "newbies" to the RV world so every day is a learning experience. I have a 2016 Cardinal 3850. We experienced numerous 12 V DC problems so dealer installed a second cut off switch directly to the batteries; this switch is either in the Open/or Closed position with instructions to leave it in the position because I have 110 at the storage facility I use. Second point is that we have had the rig for 7 months, again with constant power issues, and just got to point that levelers would not work. Dealer said to have batteries checked so I took Interstate batteries to local Interstate distributor and was told that both batteries had dead cell--same cell on both batteries which tweaked attention of the distributor but they did replace both at no charge--good for Interstate. But now I am more confused than ever and wonder if someone can give me a short tutorial about how to use the cut off switch since it is stored on 110 power and knowing that I have some of the same sources siphoning power on a full time basis. Maybe I should just keep negative leads unhooked all the time except when in use???? Regards to all.

[WolfWhistle]

A, has the converter been tested? I have only seen / experienced loss of a cell on a very old or very abused battery. whether that abuse was extreme over charging or less than adequate charging... or allowed to run dry.I would recommend that you knowing for sure your batteries are fully charged using specific gravity or correctly measured voltages... then disconnect with the BCO until needed. you didn't say or I missed it, are the Interstate batteries true deep cycle? How many amp/hr at the 20 hour standard rate?
WW

[camaraderie]

Originally Posted by CHICKDOE

again, thanks to all the replies. I've learned a bit. somebody posted that you can get custom made battery cable and I have been researching these. they will make it very simple to install a true disconnect. can I ask one more question. i'm thinking of a knife style disconnect switch installed in the negative battery lead. do you see any problem with this. the issue would be that the knife and contacts are exposed. but since it is the negative lead even if something touched it erroneously, it would be at the same voltage as the chassis so there would not be any short circuit. or should it the rotary style switch that has the contact posts shielded?

This knob switch fits on the negative post and I like better than the blade. 7 bucks at walmart...or just about anywhere including ebay & amazon.

[metalsideup]

I'll throw my 2 cents in to this dialogue. Earlier this year I installed a solar system and also two 6 volt batteries in place of the provided 12 volt. While doing this, I ran a new cable to the factory 2-lug disconnect switch located outside on the frame. My switch had 1 cable coming from the battery on one lug, but it also had another smaller wire from that lug going under the trailer to a junction box. Thus, when the disconnect switch was put in "disconnect" mode, there was actually 12vdc still being applied to some circuits within the trailer. This explained to me all the reports of parasitic loads that I've read about here. I simply removed that wire (ring terminal) from the battery lug of the switch and put it on the feed lug. Now, when that disconnect is put in to it's "open" mode, the battery is 100% disconnected. The only loss of battery potential now is the normal self-discharge rate of the battery. I disconnect my batteries for specific reasons, one of which is to isolate them from the TT while in winter storage and they are being maintained by a smart charger. If one doesn't have the facilities to electronically maintain the battery(s) while in storage, I would highly recommend they be removed and stored where they can be.

[Narboza]

Piling on, here is what is battery connected on my trailer. YMMV.

• Tow vehicle electrical system

• Emergency trailer brakes

• Level-Up controller and hydraulic motor

• Alta Remote (for slides, awning, yellow door light)

• Furrion Stereo

• Propane Detector

• Main Door Foot Light

• Docking LEDs

[CHICKDOE]

having 110 available in storage is nice! that would allow you to run the residential refrigerator. i'm not an expert but if you have 110 available why not leave the batteries connected so the converter will keep them topped off? with a cardinal I suspect you have a progressive dynamics converter which should be a quality converter. also the converter would power the 12 volt circuits even if the batteries were disconnected. you could disconnect the batteries and use a battery minder type charger / maintainer to take care of the batteries. it would plug into a 110 volt receptacle on the trailer. i'd die to have 110 available at our storage location!

[WolfWhistle]

Chickdoe,

Correctly installed factory battery cutoff switches (BCO), only break the path from battery to the converter charger (+) attachment / lug, while leaving other DC items powered that essentially are connected on the battery side of the BCO ... on purpose. Many seem to think that this is a factory mistake and are surprised that the BCO doesn't "kill" everything 12 volt. On my trailer, the much quoted but seldom understood "parasitic" load is less than 0.3 amps (less than 4 watts!). Which over time can drain a battery; it is true. It is my contention, that said battery is placed into storage with far less than a full charge to start. I would highly recommend a manual disconnect device such as pictured by camaraderie (top post type) or one in the bolt on style and used when in storage, but only after a full and knowing its full charge (12.7vdc after disconnected rest period and/or 1.277 specific gravity (per cell).

If anyone has 110 while stored, why would using a tiny "battery tender" type maintainer ... unless you remove the batteries and take them home.... be better than the already owned and built in, converter charger? Obviously it needs to be a good one like IOTA with IQ4 or Progressive with their Wizard... essentially a "smart" charger as they are called.

Edited: the WFCO 8955 in my unit works well enough for this purpose.

Off my soapbox now...
WW

[NMWildcat]

Sooooo, if the factory battery cutoff doesn't actually cut off the battery, shouldn't it be renamed? Maybe a battery restrictor, or a faux battery cutoff. And if it doesn't cut off the battery, what good is it? 😝

[WolfWhistle]

Originally Posted by NMWildcat

Sooooo, if the factory battery cutoff doesn't actually cut off the battery, shouldn't it be renamed? Maybe a battery restrictor, or a faux battery cutoff. And if it doesn't cut off the battery, what good is it? ��

I just had a thought, why don't they put sticker near it that warns that this battery cutoff switch doesn't cut off everything?? We don't have enough stickers already!

It is a very useful tool ... the battery industry is happy it's there... if you use it faithfully you can kill your battery and buy new every couple of years. I am 99% sure wired to prevent cutting off the CO detector and break-a-way is a legal / regulation thing. Trying to understand the rationale ... you know if wired like we think they should be (the BCO), someone will absolutely forget to turn it back on and die from CO poisoning or would have a runaway trailer since the break-a-way switch is no longer powered and sue the factory for negligence. I have heard the slide controller without power can cause a slide to creep open, don't know if that is true? I don't think the BCO is there to aid and assist when storing your RV. My advice is to add a real cutoff switch and ignore the factory one, but don't forget to turn it on before occupying the unit or pulling it down the road. Tie a note on the 7 way plug, or the door handle if you need to.
WW

[Mdaniels4]

I do have a question re:storage and disconnect. I have never pulled my batteries from the trailer for the winter. Only one 5er had a disconnect switch. This one does not either, but since it was just delivered in November it really had minimal charge. So i pulled it and put it on a tender for this year. Anyway, the question is is if I disconnect switch this one, and the batt is fully charged over the season, can I merely just leave the batt in place over the 5 or 6 months of winter storage without a dead batt in the spring? I've never had an issue so wouldn't assume there would be. But everyone else seems to pull their batts. Thanks.

[awellis3]

Originally Posted by WolfWhistle

I have heard the slide controller without power can cause a slide to creep open, don't know if that is true?

It's true. You disconnect the controller to manually operate the slide in an emergency. I found my wardrobe slide controller wired straight from the supply buss on the frame. I installed a switch in that circuit to eliminate the draw while parked boondocking.

[NMWildcat]

Originally Posted by awellis3

It's true. You disconnect the controller to manually operate the slide in an emergency. I found my wardrobe slide controller wired straight from the supply buss on the frame. I installed a switch in that circuit to eliminate the draw while parked boondocking.

Depends on what type of slide you have.

[WolfWhistle]

Originally Posted by Mdaniels4

I do have a question re:storage and disconnect. I have never pulled my batteries from the trailer for the winter. Only one 5er had a disconnect switch. This one does not either, but since it was just delivered in November it really had minimal charge. So i pulled it and put it on a tender for this year. Anyway, the question is is if I disconnect switch this one, and the batt is fully charged over the season, can I merely just leave the batt in place over the 5 or 6 months of winter storage without a dead batt in the spring? I've never had an issue so wouldn't assume there would be. But everyone else seems to pull their batts. Thanks.

From what I've read, a Lead/Acid flooded battery, if fully charged at the beginning should have between 88% to 52% charge left after 6 months. If stored in warm / hot temperatures charge is lost at a much higher rate (temps above 20C). Water is also lost and the 6 months, you mentioned is IMO the longest you should go before maintenance. Also, a battery with a good charge will not freeze.
WW

[NMWildcat]

Originally Posted by Mdaniels4

I do have a question re:storage and disconnect. I have never pulled my batteries from the trailer for the winter. Only one 5er had a disconnect switch. This one does not either, but since it was just delivered in November it really had minimal charge. So i pulled it and put it on a tender for this year. Anyway, the question is is if I disconnect switch this one, and the batt is fully charged over the season, can I merely just leave the batt in place over the 5 or 6 months of winter storage without a dead batt in the spring? I've never had an issue so wouldn't assume there would be. But everyone else seems to pull their batts. Thanks.

Before retirement I would fully disconnect the battery and then charge it about once a month if we didn't use the unit. Batteries lasted 5 years. If you don't charge your battery for 6 months, it will be dead.

Now that we are retired and use our RV constantly we just leave it plugged in all the time and don't disconnect the batteries.

[WolfWhistle]

Originally Posted by NMWildcat

Depends on what type of slide you have.

Mine is LCI In-Wall type, with dual velocity controller
WW