Cleaning up the mess of battery cables.

I was thinking same as you. My battery terminals are full of cables making a big job of adding water to the batteries. I have to remove the cables and remember where each one goes back to. The power post should work.

Mine came from the factory like this. One #2 wire from the battery, then several different size wires to various things. Seems like a sensible way to wire the battery.

The Trimetric shunt on the neg side gets your one fat neg wire to battery while the other end of the shunt has to collect all the incoming negs. So you need another neg bus out from that to help collect all the negs, since the shunt bolt can't take them all stacked up.

Over on the positive side, you might have a battery disconnect switch that has the one fat wire to the battery and all pos wires from everywhere stacked up somehow to the outer end of that switch. The switch probably can't hold them all stacked so you need a positive bus to take some of them.

The electrons don't care how they get there, but you lose some by stacking too many ring lugs. :) A store-bought bus avoids that issue by spreading them out sideways to several terminals instead of stacking them.

Posts are fine and you probably need a bus.

Muddydogs wrote:
My trailer battery's are a mess of wires, the posts were full from the factory then I added wires for the solar, inverter and others. I was thinking about mounting two of these power posts https://www.bluesea.com/products/category/PowerPost_Connectors/PowerPost to my trailer frame behind the battery's so I could attach all the cables to them then just run one + and - to the battery's. Would sure make checking water levels and getting the box lids on easier.

Good idea? Any other suggestions?

I have been thinking the same thing. Just been too lazy to get it done.

You can DIY a very good bus for a fraction of the cost of a store-bought bus. The only critical part is a piece of copper flat bar big enough to handle all the loads. I used a 1" x 1/4" bar,IIRC. I chose to tap the holes and use SS fasteners (don't want them coming loose). The bars are mounted in conventional 4" plastic waterproof boxes available at the big box stores. I chose to glue and screw in standoffs for the bus bars inside the boxes (HDPE). You can use your own creativity on how they are secured in the box (or not secure them at all).

A (+) phase bus:

BFL13 wrote:
Over on the positive side, you might have a battery disconnect switch that has the one fat wire to the battery and all pos wires from everywhere stacked up somehow to the outer end of that switch. The switch probably can't hold them all stacked so you need a positive bus to take some of them.

I do have a disconnect switch but 3 or 5? wires still hook to the pos battery cable. Guess I should track them down and see if they could be hooked into the disconnect switch, not sure what they go to but I can't think of anything that would require constant power in the trailer.

I will look into bus bars or a custom job as it would be nice to have something sealed to keep out the dirt. My trailer really needs something as the factory wires hang a little under the trailer and the few that come through a hole in the tongue are ridding on the metal since the hole is to big to keep the plastic grommet in place. One of these days I am going to hook a rock or sagebrush and rip some wires off.

Thanks for the input guys.

It is usual for the battery disconnect switch to not include the trailer's breakaway switch pos wire, the LP alarm, the stereo, the jacks, and the slide motor.

To get a complete disconnect, have the switch going straight to the battery and all the pos wires on the outer side of the switch. (Except leave the breakaway switch wire right on the battery positive post, and don't fuse that wire either)

The one fat positive wire going to the battery gets a big fuse that can take all the amps, then the other wires (" branches") each get a smaller sized fuse and wire gauge according to the amps on that wire branch where their fuses are located near the bus.

BFL13 wrote:

To get a complete disconnect, have the switch going straight to the battery and all the pos wires on the outer side of the switch. (Except leave the breakaway switch wire right on the battery positive post, and don't fuse that wire either)

When I was setting up my pickup to tow a tandem flatbed with brakes, I was discussing breakaway circuits with an old friend - he stated he originally had a fuse in his break-away wire. He said one day he was working his way down a long gravel hill towing a tractor on a flatbed when the fuse blew. It was all he could to to manage the impending train wreak.

He suggested I put a self-resetting circuit breaker inline.