Furrion MPPT 50A and battery disconnects

[Yoda]

Bruce - please do yourself a favor and get some black and red electricians tape and correctly mark the wires. In my book a red wire should never be connected to a negative terminal, so put a black band on both ends. Same with the black wire connected to the positive terminal - a red band should be on the wire at the ends to correctly identify it.

I would personalty clean this up and wire it a recommended by others. And Yes GD did not do this either as the positive wire from the disconnect switch to the junction and then to the distribution panel are black in thier wiring. They are the two heavy black wires on the same terminal lower connection far right. I have it on my to-do list to wrap the ends in red tape. Just need to get some red electricians tape.

Just my 02
Safe travels

Keith

[jbt816]

My ocd is way more than tape. I’m buying new cables.

[howson]

jbt816

Edit: Updated to add OEM battery disconnect.

I believe this first pic shows how your trailer is wired (just looking at the battery and solar controller connections):



Below is how I'd wire my camper (if I understand the requirements laid out in these threads). Keep in mind I'm not an electrician and just an owner like you, so scrutinize accordingly. Note I didn't try to match the wire colors actually on the camper.



The Blue Sea e-series battery on/off switch's ratings are above anything the camper will experience. https://www.bluesea.com/products/900...Battery_Switch

There's no need for a self-resetting breaker on the solar circuit. Assuming the array will not be expanded (left as delivered by GD) then a 50A circuit breaker with a shutoff will suffice, (Pic shows my 120A--that's way too big. Get a marine-rated 50A and it will work fine.)

The circuit above should give you the ability to isolate the solar controller from the batteries and completely isolate the camper from the batteries. (You can leave the OEM disconnect as installed.)

Note that the new disconnect will also remove power from the emergency brake system. A conservative approach (might be wise?) is to connect the e-brake power wire on the battery side of the new disconnect (so the emergency brake switch will never lose power).

Hope this helps. I know others are reading along, so please random reader, if you see something that doesn't make sense or you have a different approach chime in.

Howard

[jbt816]

Thanks. You’re cut/paste/edit skills are as awesome as your wiring skills.

[jbt816]

Thank you howson - new battery box for two, disconnects and breaker. Plus cleaned up the bird nest of wires.

[howson]

Thank you howson - new battery box for two, disconnects and breaker. Plus cleaned up the bird nest of wires.

Can I make one more suggestion based on what I see in the picture? (I hope you take this as a constructive input.)

Get a cover for the positive battery connection. Kind of the same type of cover that's typically seen on the positive of a car battery. A cover can prevent an accidental short between the battery terminals. (It would not be good if that were to happen.)

[jbt816]

Can I make one more suggestion based on what I see in the picture? (I hope you take this as a constructive input.)

Get a cover for the positive battery connection. Kind of the same type of cover that's typically seen on the positive of a car battery. A cover can prevent an accidental short between the battery terminals. (It would not be good if that were to happen.)

Absolutely!!

Actually I wondered why that box didn't come with some sort of cover so that I didn't lay my arm across both terminals. But you're right, I need to find something.

[Jlawles2]

something like this? https://www.amazon.com/Fastronix-Stu...-2-spons&psc=1

[jbt816]

We took a three week trip back in March. I put the RV in covered storage and turned off my new main disconnect as well as the solar disconnect.

It has been eight weeks. Today when I went to pick up the RV, my batteries were at 9 V. 😭

The batteries were new September 2022. My new disconnect cuts off everything so there are no phantom draws. Is this just normal?

[howson]

We took a three week trip back in March. I put the RV in covered storage and turned off my new main disconnect as well as the solar disconnect.

It has been eight weeks. Today when I went to pick up the RV, my batteries were at 9 V. 😭

The batteries were new September 2022. My new disconnect cuts off everything so there are no phantom draws. Is this just normal?

I don't think so--according to what is on the internet a healthy lead-acid should only lose about 4-6% of it's state-of-charge (SoC) per month. Given 8 weeks is about two months, and assuming worst-case, that's a 12% drop. A typical battery chart shows 100% is about 12.9V, so a 12% drop should have a voltage around 12.7V.

Either the battery failed for any number of reasons (it was fully charged when you disconnected it, right?) or there's a still a parasitic draw somewhere that has alluded the new switch.

Howard

[jbt816]

I don't think so--according to what is on the internet a healthy lead-acid should only lose about 4-6% of it's state-of-charge (SoC) per month. Given 8 weeks is about two months, and assuming worst-case, that's a 12% drop. A typical battery chart shows 100% is about 12.9V, so a 12% drop should have a voltage around 12.7V.

Either the battery failed for any number of reasons (it was fully charged when you disconnected it, right?) or there's a still a parasitic draw somewhere that has alluded the new switch.

Howard

interesting. I guess I have some work to do. Now I wonder if I’ve ruined the batteries.

[Jlawles2]

You may want to swap the disconnect to the negative side of the battery bank if it's not already there. I have heard of batteries loosing charge over time with the disconnect on the positive side, but not when on the negative side? I cannot explain and it's a rabbit hole I hope to never go down.

[jbt816]

You may want to swap the disconnect to the negative side of the battery bank if it's not already there. I have heard of batteries loosing charge over time with the disconnect on the positive side, but not when on the negative side? I cannot explain and it's a rabbit hole I hope to never go down.

You’re right. I should’ve put the disco on the negative side.

[AlexPeterson]

You’re right. I should’ve put the disco on the negative side.

Wouldn't matter - as long as it disconnects everything.

[jbt816]

Wouldn't matter - as long as it disconnects everything.

Possibly. In boating there can be parasitic draws when disconnecting the positive. I don’t know if I have that issue. But the main reason for using the negative would be for safety.