Battery and Solar Disconnect Install Questions

[Tony and Rhonda]

Sorry, but this is the first of many questions about our newly purchased 2017 Oliver LEII. I don't really know the maintenance history, or really know much about maintaining the Oliver, so I have lots of questions. I'll try not to flood the forum with questions all at one time.

I've read with interest about installing battery disconnect switches in Olivers that get stored regularly. Our covered storage also has a door so it's fairly dark in the bay. Our 2017 Oliver does not, as far as I can find, have a disconnect switch. We have a single, huge 300Ah LiFePo battery. Since we must keep our Oliver in storage when not in use, I intend to install one. I'm still a little confused about what parts I need. Please correct me if I'm wrong but for a basic install to add a switch to the negative side, all I need is a BlueSea switch and a short 4/0 battery cable? I've tried to study the photo @katanapilot posted but I can't identify the "extra" parts in his photo. I've also studied @tallmandan photo and this is more like what I'm trying to do right now. The photos have really helped but any advice is greatly appreciated.

I've also read that we should have a solar cutoff switch. I've looked in the street side cabinet behind the Zamp solar controller but all I see are wires going into the back of the Zamp. I haven't found any descriptions or photos of solar cutoff switches/wiring so any photos and advice on installs is also greatly appreciated.

[jd1923]

14 hours ago, Tony and Rhonda said:

Sorry, but this is the first of many questions about our newly purchased 2017 Oliver LEII. I don't really know the maintenance history, or really know much about maintaining the Oliver, so I have lots of questions. I'll try not to flood the forum with questions all at one time.

Please correct me if I'm wrong but for a basic install to add a switch to the negative side, all I need is a Blue Sea switch and a short 4/0 battery cable?

Flood away! Any and all the questions you have are good. 😂

Your are correct in the second statement I quoted. Either a shorty cable or some use a copper bar. The second picture you copied, I believe is Dan's @tallmandan. This is the more common wiring, where you fuse the positive side and switch the ground side.

Please provide pics of your battery installation and your Zamp setup. I've never seen the OTT Zamp install. In our older hull we have the Blue Sky SC. OTT installed a Blue Sea switch on the feed coming into the charger and a breaker between the SC and the positive bus. It would surprise me if one year or so later OTT went to the Zamp and installed it with neither a switch or a breaker (you only need one) at all! But who knows? Those who have the Zamp SCs please chime in. Love to see a picture of it. Best wishes.

 

[Tony and Rhonda]

 

7 hours ago, jd1923 said:

 @tallmandan. This is the more common wiring, where you fuse the positive side and switch the ground side.

Please provide pics of your battery installation and your Zamp setup. I've never seen the OTT Zamp install. In our older hull we have the Blue Sky SC. OTT installed a Blue Sea switch on the feed coming into the charger and a breaker between the SC and the positive bus. It would surprise me if one year or so later OTT went to the Zamp and installed it with neither a switch or a breaker (you only need one) at all! But who knows? Those who have the Zamp SCs please chime in. Love to see a picture of it. Best wishes.

 

@jd1923 I don't see the fuse in @tallmandan's photo. What kind of fuse should be installed? A link would be a big help.

I took some photos this afternoon.

Battery installation. I disconnected three cables to the negative battery terminal before storage. Two are not visible in the photo. Our one 300Ah LiFePo4 takes up the whole tray.

Backside of the Zamp.

The 3 remaining photos are from under the street side bed. I don't see a switch anywhere.

There is a breaker in this last photo but I'm not familiar enough with the wiring to identify where in the circuit. I see the loop to the busbar but I haven't had a chance to run all the wires down.

Any clarity anyone can add is appreciated.

Tony

[tallmandan]

8 minutes ago, Tony and Rhonda said:

What kind of fuse should be installed? A link would be a big help.

I think what @jd1923 meant with the word "fuse" was that the positive side is an always-on direct connection (not that there was a fuse breaker installed).  I didn't install any new fuse device.

My install was intended to be as simple as possible.  The use of the kill-switch on the negative main accomplished two things for me - 1. allows me to cut all power and isolate the batteries and 2. my existing negative cable that went through the wall of the trailer to the inverter was too short to reach to the front battery negative connector because it was previously connected at the rear on my four AGM batteries. --- so using the switch allowed me to re-use a short cable as an extension to reach.  It also allowed another negative connection point as Oliver wired my trailer with a bunch of wire leads all the way to the battery terminals rather than using a busbar.  This avoided stacking all the wire terminals on one negative battery post.  (The blue seas switch has large, long terminal bolts that accomodate)

JD and others have cleaned up the wiring by installing busbars.  I wasn't completely confident altering this and didn't really want to take the time to figure out, so I just re-attached all the wires in the battery bay. 

If your goal is simply to install a kill-switch.  Installing it in the negative main line somewhere is probably what you need.  Others here are much more savy at electrical than me, including JD, so they may have be able to give more specific direction...

Hope that helps...

[T-Oliver]

I found this while poking around my 2017 under the dinette seat

It’s on the positive cable 

Edited Monday at 12:12 AM by T-Oliver
Left out into

[T-Oliver]

I have a related question 

What size copper bar would I need to attach a negative disconnect 

[jd1923]

2 hours ago, Tony and Rhonda said:

The 3 remaining photos are from under the street side bed. I don't see a switch anywhere.

Agreed, I do not see power switches. In your second pictured I copied almost every device is a fuse or the obvious breaker. This wiring is foreign to me, nothing like our hull built in late 2015.

God love OTT, that they would install the display to your Progressive Industries EMS under the bed! Are you kiddin' me, now I have seen all in Ollie-land! 🤣

In later hulls they put the display in the attic which is almost as bad, without having to lift a bed! Yep, after you plug into shore power, run as fast as possible into your Oliver, open the Attic door, see that all is good, and then go back outside to get back to what you were doing!

As far as you main fuse, and as Dan wrote above, you likely have one and Dan did not change that part. He just added the shut-off switch to the ground. Yours is likely OK too, but who knows for sure until you chase it down.

If you follow your 4/0 positive cable after it enters the hull, on the left side of your battery bay, you likely have a 250A ANL fuse as we do in our hull. See my pic. This can only be seen if you open the rear dinette seat, get your head in there and look up at the opening in front of the pantry! 🤣

[jd1923]

22 minutes ago, T-Oliver said:

What size copper bar would I need to attach a negative...

Something like this:
https://www.amazon.com/Tynulox-Copper-Electroplating-Jewelry-Plating/dp/B0B9NF3X1T/?th=1

This is the cheapest one I could find on Amazon today. This would make two adequate 4" bars. When I did this in an older installation, I drilled two 5/16" holes in each end and then used heat shrink to somewhat insulate the length of the bar.

[Tony and Rhonda]

Since we are new owners I'm mostly interested in ensuring we don't do any damage to the trailer systems as we store the trailer. @tallmandan thanks for the clarification. Just like you were, I'm looking for a simple install for right now. Maybe a busbar at some future date.

I'll follow the battery positive and look for a fuse. Hopefully there's one in there somewhere.

I may go with the copper busbar @jd1923 suggested, instead of a short cable, to add the cutoff switch to the battery negative. This would prevent the switch form moving around. Are the posts on the Bluesea switch long enough to accept 1/4" stock? 

Thanks all,

Tony

[Tony and Rhonda]

Moving to the Zamp SC. I'm trying not to make assumptions here since I've never had solar before. Does the solar panel disconnect switch go between the panels (after the roof cap) and the Zamp SC or between the Zamp and the battery?

If it's between the panels and the Zamp, there isn't much room in that space. Where/how is a switch installed in that area? Pictures please.

Thanks again, Tony

[jd1923]

6 minutes ago, Tony and Rhonda said:

Does the solar panel disconnect switch go between the panels (after the roof cap) and the Zamp SC or between the Zamp and the battery?

I'm not certain re the Zamp. On our Blue Sky SC, their tech support wrote me that either side could be switched. Maybe work your cutoff switch for now and re the Zamp you could leave well enough alone since it has been fine for many years as it was installed.

 

[Tony and Rhonda]

@jd1923 When I opened the door on the storage bay and went inside the trailer, the Zamp was not happy. It was making a buzzing sound and all the lights were on/flashing. I covered the solar panels with a moving blanket and checked the Zamp again and it was silent and the lights were off. If no one on the forums can answer this, I'll call Zamp or Oliver.

Thanks ,Tony

[tallmandan]

1 hour ago, Tony and Rhonda said:

Are the posts on the Bluesea switch long enough to accept 1/4" stock? 

Definitely.  The two connecting bolts are stout and allow for more than a half inch unless you were to mount it in a panel.  Then it would depend on mount and panel thickness.  Here is a link to the one I used.  The product photos show the measurments and a diagram of possible panel mounting...or not.  

https://www.amazon.com/dp/B00558LSJE?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1

 

33 minutes ago, Tony and Rhonda said:

the Zamp was not happy. It was making a buzzing sound and all the lights were on/flashing.

Mine does this as well when it detects just a bit of light but it's not enough to have any charge function.  The buzzing sound on mine is a very faint kind-of hum.  As soon as there is more light, it fully wakes-up and acts normal.  I've never considered this to be a problem.  If I'm wrong, someone please correct me....

I don't have any disconnect switch to isolate the solar panels. The only disconnect switch I'm aware of in my 2020 LEII is the one I installed at the batteries.

[mossemi]

FYI

Mossey

[mossemi]

FYI: Solar Panel Disconnect Tutorial 

https://youtu.be/HOXnWXvLXko?si=qsyedDJUR5xAfA9F

Mossey

[Snackchaser]

On 6/14/2025 at 4:47 PM, Tony and Rhonda said:

 any advice is greatly appreciated.

Tony and Rhonda,  

From your photo, it looks like you removed the round marine hatch to see the back of the ZAMP charger.  My solar disconnect switch is mounted right next to that hatch.  From what I can see from your wiring, there isn’t one there.  This would be an easy, and recommended, install.  A  higher priority than a master battery switch.  Let me know if you need a wiring sketch.

Now on the other hand, I’m of a different opinion than some of the good folks about main battery switches.  I think they're unnecessary.  The only reason you’d need one is to disconnect the parasite loads while the trailer is in storage.  But you can do that by simply switching-off the main DC panel circuit breaker.  It's probably that one there in your picture.  Just flip it off and see if it kills the lights.

I did some measurements of the Oliver's parasite loads that you might find interesting.  Individually they were mere milli amp values, but collectively they added up to almost 1/2 an amp.  That could run your 300AH battery down in about a month!  So you'd definitely want to open that breaker when storing.  I posted those values in a post by @Dave and Kimberly   Battery depletion rate 3% or more per day... with EVERYTHING off? 

https://olivertraveltrailers.com/forums/topic/10258-battery-depletion-rate-3-or-more-per-day-with-everything-off/

Cheers!  Geoff

[jd1923]

8 hours ago, Snackchaser said:

Now on the other hand, I’m of a different opinion than some of the good folks about main battery switches.  I think they're unnecessary.  The only reason you’d need one is to disconnect the parasite loads while the trailer is in storage.  But you can do that by simply switching-off the main DC panel circuit breaker.  It's probably that one there in your picture.  Just flip it off and see if it kills the lights.

I agree with the premise here. On the rare occasion, when I need the batteries disconnected, I merely grab a 1/2” wrench and remove the ground. That’s me and we use our Oliver during all seasons, never stored nor winterized.

Issue with the latter suggestion is the breaker is under the bed! It’s a whole lot easier to cut power just inside the battery bay vs. removing bedding and mattress to do so. This is more important if you have thick heavy upgraded mattresses and your wife doesn’t want nicely made beds all messed up!

OTT mounted stuff anywhere they could glue down a board with little thought to practical use during ownership. I made a whole project and post re relocating all breakers, switches and +bus that OTT had under the street-side bed to under the rear dinette seat. Where btw the DC fuse/AC breaker panel and negative bus are located. It’s just common sense.

From the many posts I’ve read, those who regularly store their Olivers are very happy after adding a battery ground cutoff switch.

[jd1923]

8 hours ago, Snackchaser said:

From your photo, it looks like you removed the round marine hatch to see the back of the ZAMP charger.  My solar disconnect switch is mounted right next to that hatch.  From what I can see from your wiring, there isn’t one there.  This would be an easy, and recommended, install.  A  higher priority than a master battery switch.  Let me know if you need a wiring sketch.

That’s great! Now @Tony and Rhonda you have a forum electrical expert that knows the Zamp!

[Snackchaser]

5 hours ago, jd1923 said:

Issue with the latter suggestion is the breaker is under the bed! It’s a whole lot easier to cut power just inside the battery bay vs. removing bedding and mattress to do so.

If circuit breaker access is an issue as jd points out, then just add a second power panel switch in a more accessible location.  It could be a breaker or a mini battery switch mounted just about anywhere.  Under the dinette seat would be ideal!  You could even put it in the battery compartment if you need outdoor access.  It’s a relatively low amperage circuit compared to the main battery, and the wire is already oversized, so adding a little more wire length won’t be a problem.

I took a photo of the solar switch location, it’s a Blue Sea No. 6006.  Amazon has them for under $25.  This would be a good choice for a power panel switch too.

For wiring the solar switch, just remove the positive input wire from the ZAMP charger and terminate it the input terminal on the switch.  Then add a short jumper wire from the switch output to the ZAMP input.  Don’t use the typical hardware store construction wire, get the more flexible automotive wire.  Mine has enough extra wire stuffed in that space that I could cut a piece off for the jumper.

If you want to add a new switch to shut off the power panel, then just remove the panel positive feed wire and terminate it to the input on the switch.  Then add a jumper from the switch output back to the panel. 

Hope this is useful for you.  Cheers!, Geoff

[jd1923]

1 hour ago, Snackchaser said:

For wiring the solar switch, just remove the positive input wire from the ZAMP charger and terminate it the input terminal on the switch.  Then add a short jumper wire from the switch output to the ZAMP input.  Don’t use the typical hardware store construction wire, get the more flexible automotive wire.  Mine has enough extra wire stuffed in that space that I could cut a piece off for the jumper.

Nice install Goeff, on the Zamp cutoff. If there is extra length on any of the Zamp wires, that would be perfect for the short length needed to a switch in this close location. No more opening the marine hatch, easily accessible, nice!

[jdmmtx]

Can someone please educate us on why one would choose a solar disconnect versus a battery disconnect and why you wouldn't have both? Is the solar disconnect primarily a safety feature? We do understand a battery disconnect is used to eliminate parasitic draws during periods of storage. We currently have neither in our 2019 LEII and are wondering about having one or both installed.

[jd1923]

24 minutes ago, jdmmtx said:

Can someone please educate us on why one would choose a solar disconnect versus a battery disconnect and why you wouldn't have both?

Good thinking, you want both. Your batteries feed your 12VDC loads (and 120VAC loads if you have an inverter). Your solar panels through the solar MPPT charger also feed 12VDC to everything wired in the circuit. You must cut off all power sources to do M&R or make mods on your electrical systems.

Some place a blanket over the solar panels, which is fine if you must! Better to be able to open any and all electrical systems with a breaker or switch.

[Tony and Rhonda]

@mossemi Thanks for the link to the Solar Panel Disconnect Tutorial video. I'm going to have to spend some time watching his other videos.

@Snackchaser Thanks for the photo of your switch. The switch looks like it's flush mounted since I don't see any wires. Nice clean install and much more convenient than inside the marine hatch.

Installing a switch will have to wait until I can bring the Oliver back to my house but that will give me time to order parts and tools.

Thanks all!

Tony

 

[Geronimo John]

On 6/15/2025 at 2:07 PM, T-Oliver said:

I found this while poking around my 2017 under the dinette seat.  It’s on the positive cable 

Safety John says that the foil in our Ollies is very conductive. Somewhere on the trailer it touches aluminum or a grounded item.

With 250 amps potential, I know for sure an owner would not intentionally have a hair raising experience by changing a fuse and having a wrench touch the foil.  Likely be a bad day and one would "say some bad words" like John D would surely say. 

But more likely, a metal tool/case/toy/etc. could easily find it's way over to the fuse.  It likely would not do anything.  Until you hit the "Right" bump and it is bounced across this device.  Then you'll have a really bad day.

Recommend you cover it or insulate the surfaces in some way.  

GJ

 

[Geronimo John]

Battery and Solar Disconnect Install Questions

But be sure to know that they are two different things with two different purposes located in two different parts of the Ollie.

The Solar Disconnect (DISCO) only needs to handle the power of the solar panels.  Likely 200 to 600 watts.  The Battery disco needs to be able to handle 350 Amps at say 12.7V which is 4500 watts.  

The Solar disco can be less easy to get to.  Generally, it is used for maintenance and storage purposes.  But the Battery disco needs to be where you or a first responder can get to it in a dire emergency fast.  

GJ