Battle Born Batteries in Parallel - How do you make it look good?

[howson]

The posts on the Battle Born battery are not standard battery posts. In addition, their connectors are recessed so it is impossible to connect a lug at a 90 degree angle. The best that can be done is about a 45.

Battle Born makes a terminal adapter that for six of the eight connections (four batteries x 2 terminals = 8 connections) will work. But I'd have to replace the connector lugs on all the wires I've built with battery cable connectors.



For the last two connections the problem is I need to tie together four lugs. Three are 2/0 lugs from the other batteries and one is the 4/0 lub (cable) going to the inverter. I can use a Battle Born terminal adapter and then a mil-spec battery terminal kit, but there's now THREE connections between the lugs and the actual battery connection.

First, here's the mil-spec battery connector:



Here's what I mean by three connections:



In contrast to the three connections as shown above, the current setup has one connection per lug. In other words, the lug is connected right to the Battle Born battery's connector. The issue is the two connections (one positive and one negative) with the multiple lugs is *ugly* and very hard to put together.

So here's the options as I see them (chime in if there are more):

Option 1: Stop your crying, Howard. Don't worry that it doesn't look good and once the multiple lugs are connected it's done, right? Pros: Nothing needed. Cons: Looks bad, no protection for terminal covers, hard to remove or install the multiple-connected batteries if needed.

Option 2: Buy all the bits and pieces including the Battle Born Terminal Adapters and Fastronix Military Spec Battery Terminal Top Post Kit. Pros: Will look good when completed, terminals are covered, easy to remove or install connections. Cons: $$, added weight, multiple-points of contact between 2/0 and 4/0 wiring to the battery terminal (possible points of corrosion, resistance, etc).

Option 3: Buy Fastronix 3/8" Stainless Steel Single Stud Power and Ground Junction Blocks, Red and Black. Leave the single lug-to-battery terminal connections as they are. Connect the multiple-lug connections to the Fastronix blocks (which will require another cable from the battery to the lug). Pros: Easy to install and remove cables, not too expensive Cons: Two (one red, one black) small components that I'll have to figure out where to install in the small space I'm using. I may have to remake a few of the 2/0 cables.



Truly appreciate some feedback or pictures of how you've wired your Battle Born batteries in parallel.

[mbmike29]

I've always seen it done like this (in)famous YT content creator has done.

[howson]

I've always seen it done like this (in)famous YT content creator has done.

Thanks for your picture and response.

What is missing from my original post is I have four batteries and, due to space considerations, they must be like this:

[mbmike29]

Not sure where you need to tap off the batteries for your system, but you could still wire them in parallel and not have more than 2 cables land at any one post - regardless of configuration - although you'll need to make new cables or deal with the long lengths you have.

[TucsonJim]

Howard - I have three BB batts in parallel. I tried to keep the connections on the batteries as clean as possible. I crimped new connectors onto my 2/0 cables and then put shrink tubing on the interface. You can see the results in this photo:



I also used a Fastronix terminal to make all the connections that would normally go to the battery. However I prefer to use the four post terminal in order to keep things clean and simple. And the cover provides some short circuit protection. I mounted the terminal on the back of the cross brace running perpendicular to the A-frame so it was very close to the batteries.



Terminal Link

Battery Cable Lug Link

Edit 1 - This photo shows the batteries with the covers and locks installed. The mounting configuration of the cables allowed for simple installation of the covers.



Jim

[howson]

I also used a Fastronix terminal to make all the connections that would normally go to the battery.

That looks perfect.


Unfortunately I can't duplicate how you've arranged your batteries (due to space, since my batteries are in the pass-thru) but with the terminal block it should be relatively easy to put everything together. The 4/0 lug (output to the inverter) will have to double-up on one of the lugs.

Thanks, Jim.

[howson]

Unfortunately the terminal block is rated for a maximum of 250 amps. I could easily exceed this rating on a regular basis with four batteries and a 3000W inverter.



I'll have to stack the lugs on the single terminal connection point. I can't find a multi-terminal block with high enough amperage ratings.

[TucsonJim]

Unfortunately the terminal block is rated for a maximum of 250 amps. I could easily exceed this rating on a regular basis with four batteries and a 3000W inverter.



I'll have to stack the lugs on the single terminal connection point. I can't find a multi-terminal block with high enough amperage ratings.

You could combine the battery and inverter cables on the same common lug, then run your smaller loads off the different lugs. This would be the equivalent of mounting the heavy load and the battery on a single lug connection. Just make sure you go with the 3/8" lug terminals, and not the 5/16" terminals.

Jim

[mbmike29]

For your four batter configuration - here is what I would do. YMMV. My Visio skills leave something to be desired - but you get the picture. For a 12V 400Ah system I would have all wires be 4/0 welding cable. You could go to a 400A fuse before or after the shutoff on the positive side. I've seen it both ways.



Edit: Corrected picture to match your orientation.

Edit again: Don't do THIS - not recommended.

[howson]

For your four batter configuration - here is what I would do. YMMV. My Visio skills leave something to be desired - but you get the picture. For a 12V 400Ah system I would have all wires be 4/0 welding cable. You could go to a 400A fuse before or after the shutoff on the positive side. I've seen it both ways.



Edit: Corrected picture to match your orientation.

I do appreciate you taking the time to draw out a suggestion and post it, but this is what the electrical engineer at AMSolar sent me (and how I have it configured). (Note his fancy computer skills, too.)