House Batteries

[Homerhomeowner]

We replaced the 2 house batteries in our 2010 Georgetown 378S, but my husband can't remember what goes where cable wise. Can anyone help?

[WayneT]

Here is a photo of the cable connections to the house batteries in my 2014 Georgetown, if that helps.

[WayneT]

Let me add clarifying comment for the photo. I have a TriMetric battery monitor, so you see an extra heavy guage black cable that comes from a shunt used for the monitor. Normally there would be a single black cable that goes from the left battery to motorhome ground connection.

[kenandterry]

Originally Posted by WayneT

Here is a photo of the cable connections to the house batteries in my 2014 Georgetown, if that helps.

BTW Wayne....

I see the dust cap is off from one of your direct connect fuses going to the positive post.

[WayneT]

Ken, After I had taken that pic several months ago, I noticed the same thing and put the cap back on the fuse holder. Thanks for the heads up.

[Homerhomeowner]

Wayne, my husband tried this but when connecting the blue and green wires, or attempting to, when he touched them to the red post, he got a spark. Any idea why that might be?

[WayneT]

I have not changed my house batteries yet so I can't speak from experience and I am certainly not an expert in 12 volt systems, but in my experience with cars, I was taught that when connecting and disconnecting batteries to disconnect the negative ground (black cable) first and positive (red cable) last. When reconnecting the battery you connect the positive terminal first and the negative cable last. That is the way I have always done it but I cant tell you why that is important.


For the house batteries I assume you are referring to the smaller green and blue wires that hook up to the positive terminal with the red cable. If you wait to connect the negative cable last, you will not get a spark at the positive terminal when connecting any of those wires/cable because you are not completing any circuits until the ground gets hooked up.


Again, I have not actually done this with my house batteries yet and I am not an expert, so I will let others with more knowledge/experience weigh in with a better answer if they have one.

[cfo111]

do you have 6 volt batteries or 12 volts

[NXR]

Originally Posted by WayneT

...but in my experience with cars, I was taught that when connecting and disconnecting batteries to disconnect the negative ground (black cable) first and positive (red cable) last. When reconnecting the battery you connect the positive terminal first and the negative cable last. That is the way I have always done it but I cant tell you why that is important.

The reason is that you're usually using a metal wrench or socket to tighten down the battery terminal clamps. If the negative (chassis ground) is reconnected first and while tightening the red positive clamp you accidentally touch the metal wrench to the chassis somewhere you just short-circuited the battery and an immense amount of current will flow through the wrench. That can cause very serious damage to you and the vehicle, particularly if the wrench gets welded to the chassis and you cannot disconnect it from the positive terminal of the battery.

Same thing when disconnecting the wires. If you're disconnecting the black negative first and the wrench touches the chassis it's no big deal because that wire is already connected to the chassis. If you already have the black negative disconnected and short-circuit the red positive to the chassis, there really is no short-circuit at all and nothing bad happens.

Make sense?

Ray

[AbdRahim]

Always good to take a picture before disassembly.

[WayneT]

Originally Posted by NXR

The reason is that you're usually using a metal wrench or socket to tighten down the battery terminal clamps. If the negative (chassis ground) is reconnected first and while tightening the red positive clamp you accidentally touch the metal wrench to the chassis somewhere you just short-circuited the battery and an immense amount of current will flow through the wrench. That can cause very serious damage to you and the vehicle, particularly if the wrench gets welded to the chassis and you cannot disconnect it from the positive terminal of the battery.

Same thing when disconnecting the wires. If you're disconnecting the black negative first and the wrench touches the chassis it's no big deal because that wire is already connected to the chassis. If you already have the black negative disconnected and short-circuit the red positive to the chassis, there really is no short-circuit at all and nothing bad happens.

Make sense?

Ray

That is a good explanation, thank you for the education Ray.

[upflying]

I zip-tied my cables together and color coded the wire bundle with color electrical tape. I then color coded the top of the batteries near the terminals with the same color electrical tape. No confusion where the wires go now.