Dual Batteries, are mine right?

[Newk]

I have two batteries on our Salem Hemisphere 300BH, it has an inveter and residential fridge, so the dealer installed two batteries. I assumed they were installed correctly, I know... anyway, things seem to be working well. We have not tried to use the inverter. We start with a cold fridge full of cold stuff and it handles the trips just fine. I went to install a disconnect today, I pulled the negative cables off the post on one battery, but nothing quit working in the camper. Is this correct? I was assuming that these were wired in parallel, and that disconnecting both negative cables from one battery would disconnect service to the trailer. Trailer was not on shore power. I am not an electrical genius, so maybe I misunderstand how these are wired.

1. So are they wired properly?
2. How do I connect a disconnect with dual batteries?

Thank You for all the help. I have been reading a lot and learning a lot from this forum. This is our 3rd camper, but first with dual batteries.

[Evereddie]

When you say you disconnected both negative cables from one battery, where did each cable go? I assume one went to the other battery and one went to ground. Is that the case for your cables?

[Flybob]

Where does the cable on the negative terminal of the other battery go?

[Schvarak]

Originally Posted by Newk

I have two batteries on our Salem Hemisphere 300BH, it has an inveter and residential fridge, so the dealer installed two batteries. I assumed they were installed correctly, I know... anyway, things seem to be working well. We have not tried to use the inverter. We start with a cold fridge full of cold stuff and it handles the trips just fine. I went to install a disconnect today, I pulled the negative cables off the post on one battery, but nothing quit working in the camper. Is this correct? I was assuming that these were wired in parallel, and that disconnecting both negative cables from one battery would disconnect service to the trailer. Trailer was not on shore power. I am not an electrical genius, so maybe I misunderstand how these are wired.

1. So are they wired properly?
2. How do I connect a disconnect with dual batteries?

Thank You for all the help. I have been reading a lot and learning a lot from this forum. This is our 3rd camper, but first with dual batteries.

Notice, i have two deep cycle batteries. I connected the negative from the one on the right to the screw on pole on the one on the left. Then connected the disconnect to the big terminal on the left and wired the disconnect to ground.
I don't know what your disconnect looks like. Mine was purchased at harbor freight for just under $6.
Hope that helps. Notice the hole on the left? I put a 5/16 3/4" stainless bolt and nut through that to connect the ground wire to. The green knob is turned counter clockwise to disconnect the ground and clockwise to connect it. Make the pic bigger to see everything better.

[Bentspoon]

From your picture, they are wired in parallel and you have a disconnect to chassis ground. Are you sure the disconnect is functional? If so there must be ground connection somewhere else but there doesn't seem to be a stray cable anywhere from the battery. Perplexing!

[Evereddie]

Originally Posted by Bentspoon

From your picture, they are wired in parallel and you have a disconnect to chassis ground. Are you sure the disconnect is functional? If so there must be ground connection somewhere else but there doesn't seem to be a stray cable anywhere from the battery. Perplexing!

The original poster is Newk.

[Schvarak]

Originally Posted by Evereddie

The original poster is Newk.

And didn't have a picture. Which would have been helpful.

[Schvarak]

Originally Posted by Bentspoon

From your picture, they are wired in parallel and you have a disconnect to chassis ground. Are you sure the disconnect is functional? If so there must be ground connection somewhere else but there doesn't seem to be a stray cable anywhere from the battery. Perplexing!

Yes, it is. Like i said, the green knob connects and disconnects to chassis ground.

[spock123]

Originally Posted by Newk

I have two batteries on our Salem Hemisphere 300BH, it has an inveter and residential fridge, so the dealer installed two batteries. I assumed they were installed correctly, I know... anyway, things seem to be working well. We have not tried to use the inverter. We start with a cold fridge full of cold stuff and it handles the trips just fine. I went to install a disconnect today, I pulled the negative cables off the post on one battery, but nothing quit working in the camper. Is this correct? I was assuming that these were wired in parallel, and that disconnecting both negative cables from one battery would disconnect service to the trailer. Trailer was not on shore power. I am not an electrical genius, so maybe I misunderstand how these are wired.



1. So are they wired properly?

2. How do I connect a disconnect with dual batteries?



Thank You for all the help. I have been reading a lot and learning a lot from this forum. This is our 3rd camper, but first with dual batteries.

A good place to look at for batteries is the 12 volt side of life part 1. It has diagrams

[CHICKDOE]

i'm making several assumptions that you need to verify. my guess would be 2 12 volt batteries wired in parallel (positive to positive, negative to negative). and since you didn't say how the second battery was wired my guess is they are battery boxes with covers. our trailer came with two batteries like that but it also had cables connected to all four of the terminals. when I put in the disconnect I had to reroute a couple of the existing cables. I ended up with the two jumper cables between the terminals (positive to positive, negative to negative) and then all the positive cables rerouted to the positive terminal of battery #1 and all of the negative cables connected to the negative terminal of battery #2. it took a bit of effort to reroute them, but all works and the disconnect is so worth the effort!


note, if you have an inverter it is probably wired directly to the batteries with a second set of battery cables. this may be what you disconnected and left the real cables connected to the second battery.

[Newk]

I traced the wires and thought one went to the other battery and one went up under the nose. Ground? I'll try to get some pics postwe.

[Newk]

Chickdoe, I do have inverter, you may be on to something. Thanks for the idea. I'll look at both batteries and get pics up.

[jkoenig24]

You did not say if the dealer installed two 12VDC batteries or two 6VDC batteries. It make a BIG difference. Two 12VDC batteries need to be installed in parallel. Two 6VDC batteries need to be installed in series (AND, for more than two 6VDC batteries, they MUST be PAIRS of 6VDC installed in series (to give the 12VDC RVs expect) with multiple pairs installed in parallel (to boost the AmpHours). Dynamax installed TWO 12VDC batteries in my 2015 DX3-37RB to power a 22 cubic foot residential fridge. Those two 12VDC batteries, starting fully charged, will be drained in less than 12 hours. You will need to either 1: be plugged into shore power most of the time or 2: be running the diesel engine so that the alternator is charging the batteries or 3: run the onboard generator or 4: install more batteries to up the total AmpHour capacity of your RV. Several months after I bought my DX3-37RB, I paid big bucks to upgrade from two 12VDC house batteries to SIX 6VDC batteries. I more than quadrupled the AH capacity of my DX3 and, can now run said residential fridge for 48+ hours before I need ta augment my RV's batteries. Lithium is an up and coming technology but, it's still a VERY expensive option.

[Peter]

I have used the same switch and it worked fine. Did you try (with switch connected) removing ground wire from frame? This may indicate a bad switch. You might also want to inspect the switch to see if turning the knob counter clockwise actually breaks the connection. Let use know the outcome.

[Schvarak]

Originally Posted by Peter

I have used the same switch and it worked fine. Did you try (with switch connected) removing ground wire from frame? This may indicate a bad switch. You might also want to inspect the switch to see if turning the knob counter clockwise actually breaks the connection. Let use know the outcome.

No never want to remove the ground wire! That's why I bought the disconnect switch, so I wouldn't have to mess with disconnecting wires. Yes, turning the knob counter clockwise does in fact disconnect the ground. Every time!

[5picker]

Just so everyone's aware....
There are TWO things going on in this post that seem to have added some confusion.

Newk was the OP and he never posted pictures.

Schvarek posted photos of HIS set-up hoping it would help Newk understand about his problem.

[Schvarak]

Originally Posted by 5picker

Just so everyone's aware....
There are TWO things going on in this post that seem to have added some confusion.

Newk was the OP and he never posted pictures.

Schvarek posted photos of HIS set-up hoping it would help Newk understand about his problem.

Exactly!! FINALLY!!! Problem is, i have no help for him regarding inverters. Whoever installed his pair of batteries should have made sure of the inverter too. I would hope this guy (installer) had some experience there. If not, it's time Newk finds someone who does.