Wire size parallel

[Mountainlion]

Hi guys,

I’m installing 2 x 280Ah batteries in parallel on my boat.

Have been running 4/0 marine wires (105C) between battery fuse (400 Ah) and Victron Multiplus 12v/120A/3000W.

Typical high draw will be 1800 W when induction top is used. (But would like to size system for the 3000W inverter capacity even if it most
probably never will be used at that high rate)

My question.

I’m pondering how to connect the two batteries in parallel?

If I go with a star configuration with a Lynx distribution busbar it seems overkill to run 4/0 between busbar and batteries? Each battery will provide maximum
200Ah. ( Fused in the Lynx distribution busbar) Distance between batteries and busbar 2.5 feet. My calculations tells me 2/00 would be sufficient?

The second alternative (less expensive) would be to connect both batteries in parallel and go from opposite ends to
to T-fuse and Shunt.

Any thoughts are appreciated.

 

[Rocketman]

I would go Option #1 - Buss bar w 2/0 wire.

It is easier to service (pull one battery out for service while leaving everything connected). And gives you the easy option of adding another battery (can we ever have enough batteries or solar?).

But I am just some dude on the internet…

Good Luck

 

[SupraSPL]

I use 2/0 with 6 ' lengths between a pair of 12V 300Ah and 3000W inverter. Technically supposed to be 4/0 but sounds like 99.9% of the time, voltage drop won't be taxing you.

 

[Mountainlion]

I use 2/0 with 6 ' lengths between a pair of 12V 300Ah and 3000W inverter. Technically supposed to be 4/0 but sounds like 99.9% of the time, voltage drop won't be taxing you.

Agree. I used 2/0 between a 280Ah/12V and a 3000 W inverter in my RV. Works flawless. But in a boat I need to comply with ABYC so
better to follow the recommendation's…….