question

KD avatar image
KD asked

48/3000, distributor, cerbo gx, DIY 48v battery question wiring things

Hi all.

Preface with I've done some car audio wiring/etc back in the day, so not a complete noob with wiring things up. I have various test equipment (MM, wire tracer, etc).

So I am building a couple of 48v 302AH 16c packs soon. I've watched a few videos (Prose, etc) on victron gear. I purchased the 48/3000 MK2 unit, along with a Lynx Distributor, 1000a battery monitor, and cerbo gx. The goal is to build 50Kwh to 100Kwh of storage eventually, but right now I am looking at a single 16cell 48v battery that has a 100a BMS.

The various videos I see mostly show the 12v setups, a couple 24v and a few 48v setups. I am aware that 12v requires much thicker cable due to the 4x more amps vs 48v. That said, many of the 48v videos I see seem to use 2/0 cable from the 48/3000 to the distributor, and from there to the battery. Is that pretty common given the max 3000watt/25a loads it can handle on the AC out? That seems oddly very large wire for a max 25a or so output?

I should add that this is just to run some home video equipment for now. My damn energy bill is stupid high and peak hours are when I am usually home/doing stuff, so trying to offset that by charging battery bank(s) in off peak (using AC IN 15a wall outlet) and for now one battery bank (about 3Kwh or so worth of storage).

I will supplement that with solar eventually as well, which is another reason I opted for the Lynx distributor, so I can feed an MPTT to it as well at some point when I can expand my system.

As far as I can tell, 2 gauge wire would be enough in my situation as that can push 130a, and my BMS is only 100a.. and the wall outlet is only 15a max, so I'll never push more than 13a (will limit the input current a bit so as not to trip the breaker) to the battery.. at least not until the solar is added. Even then, I can't see it doing more than 50 to 60amps at most. If that.

So I am trying to figure out what gauge wire to buy to connect the battery to the Lynx Distributor, and what fuse I should use for that on the distributor?

I bought the battery monitor which I believe I would connect at the Neg terminal between battery and Lynx? Or is it better to put that on neg terminal between Lynx and 48/3000 inverter?

Got a 350a switch and again does this go best between battery and Lynx or between Lynx and inverter on the POS side?

Some say to put a fuse on pos side between lynx and inverter as well.. is that necessary? Also would one wire the inverter to the side bus bar pos/neg terminals.. I don't plan on adding anything to that at this point.

I did read the 73 page PDF (most of it.. skimmed a little for 12/24 as that didnt pertain to me specifically). Prob watched about 100+ hours of videos and yet I am still not 100% clear on these few things. So any help is appreciated. Thank you much.

cerbo gxLithium Batterywiringmultiple inverters
2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

1 Answer
Mike Dorsett avatar image
Mike Dorsett answered ·

1) Wiring size - If runs are short, the 25 or 35mm^2 cable will do. Max inverter current (peak) will be 120A.

2) Battery monitor - Between the Lynx negative and battery negative. Battery negative must not be grounded.

3) Switch and fuse: Between battery positive and Lynx positive, with 150A fuse. The inverter is not internally fused so don't miss this.


2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.