Questions about "nesting" or daisy chaining bus bars

[whereitsat42]

Hey all, beginner here with a dumb question: I'm using the experience I gained from a 12v system I built in my detached garage/workshop to start building out my main house for solar as well, and had a question about bus bars. My plan is to set up six 24v 200Ah LifePO4 batteries in parallel, along with an 80A charge controller and two 4000W power inverters. I've already made sure everything's properly sized and have fuses for all the right places, but whereas I I wired one battery to the next in parallel in the 12v system, I was looking to make my life easier with the 24v system by using bus bars. Only problem is that, by my count, I have 9 separate components and most of the bus bars I see have a max of 4-6 actual terminal screws.

Is it possible/safe to "daisy chain" multiple bus bars together to "expand" the capacity enough to support these components? My thought was maybe connect three batteries each to two pairs of bus bars (pair meaning one positive one negative), have a third bus bar pair that I connect the charge controller and inverters to, and have each of these bus bar pairs connect to a "master" pair of bus bars, this way everything is still in parallel, and of course I would make sure that the bus bars I use would support the current and voltage that would be going through them in this setup. Of course, if this is either inefficient or a good way to ruin my stuff or blow my house up, I'd like to know that ahead of time as well.

Thanks in advance to anyone who can provide some guidance on this!

 

[Q-Dog]

You can buy or build bigger bus bars.

DIY busbars... 4/0 awg

I'm planning to build some bus bars... I will be feeding two, 1/0 gauge cables from a pair of batteries on one end into a 4/0 gauge cable to an inverter on the other end Of course there will be various other connections made on these busbars as well... I'm wondering if a 2-in wide x 1/8"...

diysolarforum.com

 

[chrisski]

Is it possible/safe to "daisy chain" multiple bus bars together to "expand" the capacity enough to support these components?

I can't say its to code for your AHJ, but I daisy chain busbars.

I have two batteries combined on a busbar prior to that combined feed going to my main power distribution bar.

The main power distribution bar is a 8 post 3/8" stud Blue Sea busbar.

In your case, I'd combine the six batteries on a common busbar prior to sending this to the next bus bar. FOr me, doing it this way makes cutting the parallel battery cables to size much easier. In the VIctron Wiring unlimited guide, they list a way to parallel batteries with busbars.

 

[whereitsat42]

Super, thanks folks!

 

[chrisski]

If you haven’t bought components yet, have you considered 48 volts?

You are talking a 30 kWh battery pack and a 4000 watt inverter. Down the road, wiring for 48 now could save you some headache’s if you upgrade the inventer.

 

[whereitsat42]

If you haven’t bought components yet, have you considered 48 volts?

You are talking a 30 kWh battery pack and a 4000 watt inverter. Down the road, wiring for 48 now could save you some headache’s if you upgrade the inventer.

Nah I already bought all the components, but I'm fine with 24v. Definitely not doing 12v again though!

 

[Rocketman]

While not cheap…

The Victron PowerIn is setup for just that kind of thing. You would need two of them for the six batteries. Can add fuses so each battery has a fuse (easy disconnect point).

Remember KISS - Keep It Simple and SERVICEABLE. (I am always messing up the last one ?)

Good Luck

 

[Hedges]

You can stack ring terminals on busbars.
You can put ring terminals on top of busbar, others on bottom. Mine are bolted through, but if tapped you should be able to do it by torqueing bolt first, then using a nut to connect more on other side.

DIY Bus Bar

Im looking to make my own DIY Bus Bar that can pull 1000amps as buying one is expensive. Im looking to use it to connect a large battery banks. Can this be dune with supplies from hardware stores? Anyone know a good way to make on and what parts to use? The only one I can buy is this...

diysolarforum.com

Daisychaining, you could fuse from battery at highest current like inverters to first busbar, fuse at lower amperage to another busbar.