I have a 12v system utilizing an 800ah battery bank and my goal is to use a 1/4 inch by 1 inch wide copper bar as a bus bar to connect the positive terminals and then negative terminals appropriately. My question is if the 1/4 inch by 1 inch wide copper bar is enough to support my system? I’m struggling to understand how I would determine if these bars are correct or if I need to go with something thicker or just use 4/0 cables like most everyone else. The system is connected in parallel. Thank you in advance for any guidance!
Connecting battery bank with bus bar
- Thread starter Spamjella
- Start date
You can calculate this by cross section (I'm in metric land, so mm^2 for a cable is the same as the mm^2 cross section of a bus bar).
A 1/4 inch by 1 inch bar --> 6mm x 25mm --> 150mm^2
According to an ampacity chart (like this one), 150mm^2 is good for 262 Amps. Do you intend to draw more than 3kW? By the way, 4/0 cable is 120mm^2, so you're over that...
A 1/4 inch by 1 inch bar --> 6mm x 25mm --> 150mm^2
According to an ampacity chart (like this one), 150mm^2 is good for 262 Amps. Do you intend to draw more than 3kW? By the way, 4/0 cable is 120mm^2, so you're over that...
I do not intend to draw more than 3kW as my inverter is just that, 3kW.
chrisski
Solar Boondocker
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You mentioned busbars or 4/0 wires. As a mobile application and for ease of assembly, I used 4/0 after the batteries, but the individual cells were connected with 1/4” X 3/4” busbar. I have a slideout tray with the two batteries that a busbar makes impractical.
IMO, either wires or busbar is fine as long as you can assemble and disassemble easily, and wires and busbars meet ampacity. For high wattage items, cable runs are usually short and rarely does voltage loss come into play provided wire with correct ampacity was used.
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In my signature block is a link to how to wire a battery bank with some math to it. I have two batteries, but I used Method #3 so all batteries share the load equally.
My batteries are joined at a bus bar that has seven other inputs including a charger, SCCs, and an inverter.
There’s other options out there. The Victron wiring guide has a busbar option.
IMO, either wires or busbar is fine as long as you can assemble and disassemble easily, and wires and busbars meet ampacity. For high wattage items, cable runs are usually short and rarely does voltage loss come into play provided wire with correct ampacity was used.
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In my signature block is a link to how to wire a battery bank with some math to it. I have two batteries, but I used Method #3 so all batteries share the load equally.
My batteries are joined at a bus bar that has seven other inputs including a charger, SCCs, and an inverter.
There’s other options out there. The Victron wiring guide has a busbar option.
