Battery Busbar?

[Dan McMartin]

This is probably several questions. Seems like battery busbars are a good idea. My coach has several positive and negative leads connected to the battery bank (4-12v Interstates) and they are spread out among the batteries...trying to spread the load I guess.

To add to that mess, I'm trying to install a battery monitor. My batteries are on a sliding tray but not in a weather tight compartment. The shunt will have to be installed in the weather tight compartment next to the battery bank.

I want to add the busbar in the battery compartment, bring all the negative loads to it and then a single, large wire to the shunt through a grommet. Bringing all the negative leads directly to the shunt would be a nightmare (I's probably have to lengthen some, if not all). Then take a similarly sized wire back through the grommet and to one of the batteries (and I suppose I should do the same to the positive leads, sans the shunt of course, to balance the loads).

Does this sound like a good idea? How many amps should the busbar be rated for? 100 enough? I'm guessing the RV doesn't pull and the batteries can't handle more than that but I can't seem to find that info. And finally, if I size the wires from the busbar to the shunt and from the shunt to the batteries, is that good enough or maybe too much wire?

[twinboat]

I've used these on my boats 800 AH battery bank. Great prices and good quality.

https://www.vtewarehouse.com/content...arge4point.php

[Ndrorder]

Since no one else has answered, I'll take a shot.

Unless you have a 24V system or higher system, your batteries would be wired in parallel. Connecting the various wires to the different batteries would make no difference with respect to spreading the load. It probably more to reduce the clutter at the terminals of a single battery.

It sounds like you have a handle on the wiring. Big negative cable from the battery through a grommet to the shunt. Big negative cable from the shunt through a grommet to the bus bar. All the individual wires including the big negative coach wire would wire to the bus bar. Size the bus bar to handle the charging amps from the converter plus the total amps of all the individual little wires. I'd base the total amps from all the individual wires on the total of the installed inline fuses, assuming there are fuses.

Positive could be 2 different ways. First is like the negative. Big cable from the battery to the bus bar. Then from the bus bar to big positive coach cable and all the little cables. Second - leave big coach cable connected as is and use a smaller appropriately sized cable from the battery to the bus bar. Then, from the bus bar to the smaller individual wires. Could use a smaller bus bar on the positive in this option.

Hope it helps,
Cliff

[Dan McMartin]

Originally Posted by Ndrorder

Since no one else has answered, I'll take a shot.

Unless you have a 24V system or higher system, your batteries would be wired in parallel. Connecting the various wires to the different batteries would make no difference with respect to spreading the load. It probably more to reduce the clutter at the terminals of a single battery.

It sounds like you have a handle on the wiring. Big negative cable from the battery through a grommet to the shunt. Big negative cable from the shunt through a grommet to the bus bar. All the individual wires including the big negative coach wire would wire to the bus bar. Size the bus bar to handle the charging amps from the converter plus the total amps of all the individual little wires. I'd base the total amps from all the individual wires on the total of the installed inline fuses, assuming there are fuses.

Positive could be 2 different ways. First is like the negative. Big cable from the battery to the bus bar. Then from the bus bar to big positive coach cable and all the little cables. Second - leave big coach cable connected as is and use a smaller appropriately sized cable from the battery to the bus bar. Then, from the bus bar to the smaller individual wires. Could use a smaller bus bar on the positive in this option.

Hope it helps,
Cliff

That helps and sounds like exactly what I was thinking.

As far as determining all those loads on the smaller wires, not sure how to go about that. Turn everything on and measure? Base it on the wire sizes? Or just overestimate and go with 250 amp and size the big wires accordingly? Just go 2/0 AWG and call it a day?

[drdarrin]

The buss bar is how I connected all negative and positive wires in my solar install. Different bars of course.

[Scottybdivin]

The busbar is especially important for your negative cables, since you said you are installing a BMK. I have been happy with the Blue Sea brand.