Ca here- DC / battery cabling question

[Ben2022]

I’m putting together my SOL-Ark 15k system and will have a server rack of Ruxiu batteries. This will be a grid tied/hybrid system but I’m doing it all DIY. I want to make things to code even though I’m not going to permit it.

My question is regarding the cable from the battery rack to the Sol-Ark. I’m planning on using 4/0- the idea was welding cable for flexibility. I need to run the pair probably 10-15 feet to the inverter.

In Ca or per NEC does this need to be in conduit?

EMT only or can I use flex (everything else will be EMT)?

Can welding wire be used in conduit?




I’ve done several google searches and a few searches of the forum but I find too much conflicting information or situations just different enough to make me question it. I’ve read all DC wire inside a building must be in conduit, then saw that may not be right. Then read, welding wire can and can’t but used at all or can’t be in conduit. Since the battery is on wheels is it “building wire” or not? I don’t know anyone personally locally that has a battery system to ask.

TIA

 

[Hedges]

I'm not sure, so will be watching responses. I suspect wires need to be in conduit.
SMA says not to use PVC conduit for battery cables due to warmth.
Of course, DC indoors likely requires metal. Flexible MC, EMT, metal wiring boxes whichever convenient ought to be fine & pass inspection.
Question will be whether inspector is a stickler for UL listing on the battery cables. Looks like that is available, so best chance for success:

Custom Battery Cables with Ends - Flexible UL Listed Wire

www.batterycablesusa.com

My running system is outside, just has battery or welding cable running around expose. Other system in progress is in basement. Oh, 3-phase setup in garage, stitched with whatever wires I had for now (including THHN/THWN daisy chained, will make star to battery eventually.)