Swapping Out Batteries

[Fueco]

I bought some new batteries for our trailer, and will be removing the old ones and installing new ones tonight. Batteries are Interstate SRM-24 Deep Cycle.

Am I correct with the following assumptions.

1. I need to have no power going into the battery (solar or shore).
2. I should shut off power to the unit from the batteries.
3. It’s safe to touch the battery posts as long as I don’t connect them together with anything metal.

Anything else I need to keep in mind? I’m planning to mark which cable goes where and take a before picture for reference.

 

[TheLooks]

Put up a picture of the cables. Many times factory or previous owner installed batteries are not cabled in the most efficient way. This can hurt the life of your batteries.

 

[Fueco]

 

[TheLooks]

The way it is wired you are pulling and charging the one battery with the cables on it from and to the rig. Move the negative cable to the far left in the picture to push and pull power from both batteries equally.

 

[Fueco]

The way it is wired you are pulling and charging the one battery with the cables on it from and to the rig. Move the negative cable to the far left in the picture to push and pull power from both batteries equally.

Are you referring to the negative cable in the middle?

 

[TheLooks]

There are 2 negative cables and one positive. I would move both negative cables to the left. This makes the 2 batteries act like 1. The power in both directions must travel thru both batteries equally. The battery on the right is doing all the work and getting charged the most.

 

[Fueco]

There are 2 negative cables and one positive. I would move both negative cables to the left. This makes the 2 batteries act like 1. The power in both directions must travel thru both batteries equally. The battery on the right is doing all the work and getting charged the most.

That makes more sense. The way you worded your response suggested moving one cable.

 

[Fueco]

Would the way it’s currently wired lead the battery power indicator inside the trailer to give funky readings? It’ll sometimes go from empty to 1/3 to 2/3 to empty to 2/3 to full in seemingly random order.

 

[Fueco]

Anyway… New batteries installed. We’ll see how camping with no shore power goes this weekend versus the past two.

I couldn’t change the position of those two negative lines since they aren’t long enough to reach. Is that crucial enough to go back and extend them at some point?

 

[TheLooks]

There are many configurations for multiple batteries. You may never notice the difference in a 2 battery setup. I automatically look for the best configuration now after some schooling on it. You could flip the left battery around and then only need a longer positive to reach.