Lets talk about battery cables I want to make.

[Yoda]

OK I am trying to finalize what I need for this spring project so I can buy on a budget, putting a material list together, etc. I hope you folks don mind another question or to or three....Stop Keith

I have been doing a lot of reading today and YouTube including a lot of Will's stuff. For the sake of this discussion lets assume 4 battle born in parallel (100 to 110Ah each) or 4 6V GC2 in series/parallel (220 to 255AH each) both delivering 12V to a 3000 inverter or inverter/charger such as the Victron 3000 unit.

Please check my math.

BB have a max discharge rate of 100A. Not sure of the limits of a GC2 6V. Using this rate and using the bluesea chart I need 4AWG between the battery's (possibly 2awg) and 2/0 to the inverter. Inverter will be whiten 6 feet of the battery pack. However I am curious if I need to up-size between each parallel connection for the amperage output accumulating between connections in either set up. I am wanting to fabricate my own cables, but want to do it once for either situation, so the sizing needs to cover both situations.

The best battery cables, for an RV should be made out of welding power cable. However the front bay where the battery's will be is not 100% environmental proof and per Will I should consider marine grade cabling which is much stiffer. Thoughts? I am leaning towards the welding cable for ease of routing

Last is the cable crimp lugs. I know they should be pure copper or tinned copper. However there are numerous hole sizes available. BB 's come with 5/16 bolts for their lugs and it appears the Trojan is the same. Is this standard across the brands for the GC2 batterys?

Last What are the good sources for these materials (cable/lugs) as I am finding prices all over the map. Looking for good sources. I have seen several positive posts about batterycablesusa.com

Last - battery box. I found one to fit the 4 CG2's https://allbatterysalesandservice.co...atteries-gcq-g but not one for the 4 BB battery's. Yes I know I don't need a box for the BB's, but I want to use the space over the battery's if possible for soft stuff.

Thanks for any help
Keith

[Jkwilson]

Welding wire is sweet to handle, but it tends to wick water which can lead to corrosion. Marine wire has larger strands, reducing the wicking action, and the tinned wires are less prone to corrosion.

I would have the cables made. These folks https://www.genuinedealz.com/collections/rv do a good job and are fast.

The maximum output current of the batteries isn’t as important for wire sizing as the maximum load current from your equipment. The GC2s can probably source in excess of 1000A, so you can’t easily size for that. Maximum load is where you select your circuit protection device to protect the wire. That said, the heaviest gauge you can work with is usually the best choice to reduce voltage drop. Some times it comes down to the size of terminals available for different wire sizes.

[50ST8R]

OK I am trying to finalize what I need for this spring project so I can buy on a budget, putting a material list together, etc. I hope you folks don mind another question or to or three....Stop Keith

I have been doing a lot of reading today and YouTube including a lot of Will's stuff. For the sake of this discussion lets assume 4 battle born in parallel (100 to 110Ah each) or 4 6V GC2 in series/parallel (220 to 255AH each) both delivering 12V to a 3000 inverter or inverter/charger such as the Victron 3000 unit.

Please check my math.

BB have a max discharge rate of 100A. Not sure of the limits of a GC2 6V. Using this rate and using the bluesea chart I need 4AWG between the battery's (possibly 2awg) and 2/0 to the inverter. Inverter will be whiten 6 feet of the battery pack. However I am curious if I need to up-size between each parallel connection for the amperage output accumulating between connections in either set up. I am wanting to fabricate my own cables, but want to do it once for either situation, so the sizing needs to cover both situations.

The best battery cables, for an RV should be made out of welding power cable. However the front bay where the battery's will be is not 100% environmental proof and per Will I should consider marine grade cabling which is much stiffer. Thoughts? I am leaning towards the welding cable for ease of routing

Last is the cable crimp lugs. I know they should be pure copper or tinned copper. However there are numerous hole sizes available. BB 's come with 5/16 bolts for their lugs and it appears the Trojan is the same. Is this standard across the brands for the GC2 batterys?

Last What are the good sources for these materials (cable/lugs) as I am finding prices all over the map. Looking for good sources. I have seen several positive posts about batterycablesusa.com

Last - battery box. I found one to fit the 4 CG2's https://allbatterysalesandservice.co...atteries-gcq-g but not one for the 4 BB battery's. Yes I know I don't need a box for the BB's, but I want to use the space over the battery's if possible for soft stuff.

Thanks for any help
Keith

I use the welding cables because of their flexibility. Found a reliable hydraulic crimper on Amazon as well as 3/8 lugs. I need to go to 3/8 to go on the terminal bus bars and in-line fuse.

[colan]

I use a hydraulic crimper I purchased on Amazon.

I’ve been accused many times of building brick outhouses. A phrase used my area as meaning overbuilding. Both 4awg and 2awg feel really undersized to me. Backing that up I’ve seen installs ripped out for having too small conductors, but never ripped out for too large.

In the typical four battery parallel wiring (positive to inverter from battery 1, positive 1 to positive 2, positive 2 to positive 3 and so on, at max discharge the wire to the inverter is carrying 400 amps, the wire between battery 1 and 2 is carrying 300 amps, and so on. Same applies to the negative cables.

This leads to my typical approach when attaching batteries in parallel or series parallel I typically use 4/0. The only time I use 2/0 is for smaller installations or when using a Victron Lynx - a fused battery combiner.

With the Lynx each battery is wired directly to it. The Lynx handles the combining of the batteries for a parallel feed to the inverter. With this setup batteries are wire directly to it with 2/0. From the Lynx to the inverter 4/0.

[gbkims]

5/16" Lugs for battle born as 3/8" lugs hit the battery case.
For lugs and wire TEMCo. They sell on ebay, their site, amazon.
Lugs - TEMCo Tinned Copper Lug Ring Terminals Battery Wire Welding Cable AWG
https://www.ebay.com/itm/TEMCo-Tinned-Copper-Lug-Ring-Terminals-Battery-Wire-Welding-Cable-AWG/382056549608?hash=item58f4584
Battery Interconnect & Inverter - Welding cable with heat shrink over wire ends.
Multiplus 12-3000 manual says (2) 1/0 for each DC connection, which is about 4/0 equivalent.

edit: Marine How To - Battery Cables https://marinehowto.com/making-your-own-battery-cables/

[ncitro]

Yoda I ran 4/0 for all my parallel connections and my inverter run which went through a fuse and a switch and had to be terminated at each. You'll find a mix of 5/16 & 3/8 studs on the batteries, fuse holders, terminal strips, and switches. My Lion batteries had a metric lug but it was smaller than 5/16, so I used 1/4. So to answer your question no, no standard. I got my 4/0 from a seller on eBay who made them to length. The rest of my connections for the solar and bus bars to connect the rig wiring I made add used this kit for the terminals.

RockDIG 50 pcs AWG 8/6/4/2 Heavy Duty Bare Copper Lugs, Closed End Tubular Ring Terminals, Battery Electrical Cable Wire Connectors Assortment Kit(with 50 pcs Heat Shrink Tubings) https://www.amazon.com/dp/B07XD8616Y...ing=UTF8&psc=1

This is the eBay seller I used.

https://www.ebay.com/itm/4-0-AWG-GAU....m46890.l49292

[Cate&Rob]

Yoda
Hi Keith,

You have read how I make my own battery cables with welding cable. Similar fine strand marine grade wire is available and has the same flexibility with tinned wire strands, but is much more expensive and not worth the cost unless you are in a marine salt water environment (in my opinion). https://www.ancorproducts.com/en/119010

I use tinned copper lugs from ElecDirect https://www.elecdirect.com/lug-compr...ed-copper-lugs They have any combination of wire and lug size at reasonable prices.

The right tool to cut the large cables with a clean square end is equally important. Shearing cutters will leave a ragged or angled cut end that will not be the best fit into the lug. An "anvil" single blade cutting tool works best.

Rob

[howson]

Yoda (Keith),
One item that is easy to overlook is the comprehensive diagram of my installs has the wire gauge documented. The wire size was per AMSolar's guidance when I bought/installed my system.

All of the items you're considering can get very expensive quickly. But when it comes to the wires and connectors: no compromise. Whether you make them yourself or buy pre-made, get top quality wiring components.

I've no doubt you've seen Will's video, but for others reading this thread I'm posting it again. The title suggests the topic is for solar, but it applies to all of the components in your contemplated system:

Off-grid Solar Buyer's Guide: DC Wire and Connectors (Will Prowse Video from YouTube)

[howson]

Yoda
Per your PM request, below is a sample of all the cables I purchased through AMSolar (most came with the initial "kit"). To find where they were used please consult my schematic. I hope you don't mind me posting the info here as it may be useful to others, too.

AMSolar-Proprietery Wires (Roof Mounted)

What you see on the wire is all the information I have other than what is on AMSolar's website.



Welding Cable



6/4 Wire for 120vAC (To and From Inverter--I didn't use this wire. Instead I used "regular" wire from Lowes due to length issues with what was sent and cost).

[Yoda]

To find where they were used please consult my schematic.

I am glad you posted the information it shows AMSolar uses quality wire.

I did some digging with the embossed coding on the wire:
Panel connection cable is made by Philatron E114233 https://ww1.prweb.com/prfiles/2018/0...Cable-2018.pdf SJTO designation can be found here http://www.chem.cmu.edu/groups/bier/...powercords.pdf What is strange it does not seem to be labeled UV resistant or rated PV, but AMSolar says it is. As they do custom wire I have not found another source.

Question. The 2/0 cable shown was for wiring the battery's? Correct? My eyes thought that what was labeled on the schematic, but not sure.

Now the good news - it is not all that expensive. I forgot to figure it is two cables and that running two PV rated cables such as the TEMCo is $2.48 FT

Again thanks for the help

Keith

[Retgw2]

Hi Keith,

If you end up building your own cables you might check out https://www.windynation.com as well. They also sell on Amazon but their prices are better if you purchase directly through their website with fast free shipping and no tax.

Brian

[Yoda]

Thanks folks Great information.

Now this is going to sound like a dumb question but based on several layouts you folks have posted. It looks like a bank of 4 battle born battery's are in my future (because if I don't you will all shame me) I like the wiring to a buss bar (one for positive and negative), then to the Victron or other equipment folks have used through a fuse and switch. Doing it that way it looks like 2/0 is good.

But the question is how did you measure for and determine the length of wire you need to get. As howson Howard mentions this stuff can get expensive quick and from the prices I am seeing I don't want to order too much or too little.

Second buss bar sources? Any help? I think I need 400 amp rating to match the fuse and switch If I read the Multiplus instruction/specifications correctly.

Thanks folks
Keith

[ncitro]

Thanks folks Great information.

Now this is going to sound like a dumb question but based on several layouts you folks have posted. It looks like a bank of 4 battle born battery's are in my future (because if I don't you will all shame me) I like the wiring to a buss bar (one for positive and negative), then to the Victron or other equipment folks have used through a fuse and switch. Doing it that way it looks like 2/0 is good.

But the question is how did you measure for and determine the length of wire you need to get. As howson Howard mentions this stuff can get expensive quick and from the prices I am seeing I don't want to order too much or too little.

Second buss bar sources? Any help? I think I need 400 amp rating to match the fuse and switch If I read the Multiplus instruction/specifications correctly.

Thanks folks
Keith

Its been a while since I did my calculations, but I ran 4/0 from the batteries to the switch, fuse and inverter. Then I ran through a 100 amp fuse into a smaller bus bar (with #2 wire feeding it) to pickup all of my other loads. All negatives went through the BMV shunt obviously. This made more sense for me because everything except the inverter needed smaller terminals, and I could get a cheaper bus bar. I do not have a photo of it finished, but here is one with it in process. The bus bar is behind the batteries, and the solar comes into it. It also feeds another bus bar on the right side that replaces the factory DC connections. I got a small 12v fuse panel and wired all of the factory connections into that, and a couple of 50 amp fuses for big loads. For length, I ran 4/0 jumpers between the batteries, and measured those out once I had them in hand. The rest I kind of guessed at, trying to keep them as short as possible. Obviously thats one advantage of making them yourself, you can cut to length.

[howson]

Yoda
You installed Sumo springs--you can make cables. It's not rocket science. A couple of tools (who doesn't like tools?) with quality components and you're off to the races. Then you can make the cables to the exact length desired after the hardware is in their permanent locations. (Trust me--it will change once you start the process!)

If you look at the end of my inverter PDF I documented all the tools I used to make cables.

Howard

[Yoda]

Yoda
You installed Sumo springs--you can make cables. It's not rocket science. A couple of tools (who doesn't like tools?) with quality components and you're off to the races. Then you can make the cables to the exact length desired after the hardware is in their permanent locations. (Trust me--it will change once you start the process!)

If you look at the end of my inverter PDF I documented all the tools I used to make cables.

Howard

Howard - please pardon my CRS. I just searched for that PDF - found a whole bunch of others (you have been busy) but not that one. Forgive me but could you post a link?
Thanks
Keith

On edit - found it but I cant post the link for some reason. I think this is it
https://gdrvowners.com/filedata/fetch?id=23537