Advice Plz! Cable Size for 400ah battery string??? with room to grow?

[texman38]

Here is a quote from another thread
"On the other hand, a bank of 2-3 strings of 6 volt @ 220 AH "Golf Cart" batteries is not a bad bank. It is cheap, relatively rugged and reliable, and will probably last you 3-5 years"
looked like a good/reasonable plan IMO... I'm just starting, so my system is small (2 60 cell panels with a 40a CC) so it was recommended to use 4 x 6v golf cart batteries (which i already have some good golf cart batteries) in my cart they are wired with 4awg wire in series (36v golf cart) so i'm planning on pulling the 4 best to compose my battery bank... what size cabling should i use? I saw a video where a guy had some huge cable 2/0 looked like? I'd like to go big enough to reuse down the line (so i'm not having to rebuy/make new cables later, should i decide to grow my battery bank. Is there a certain size that is "big enough" to handle most reasonable sized battery banks? thanks!!!

[NEOH]

Review some websites that describe "Wire Size vs Ampacity"

like this one ...

http://www.cerrowire.com/ampacity-charts

[texman38]

Review some websites that describe "Wire Size vs Ampacity"

like this one ...

http://www.cerrowire.com/ampacity-charts

thanks but i don't get it??? i know use-2 is the column (i guess) for pv wire but what about battery cables, they are fine strands as well. and still just would like an answer to my question 4 6volt batteries in series 24v system what size cabling? with room to grow? i can wire A/C all day long no worries, dc stuff is still a mystery, with different loads, so with a 1000w inverter hooked up, powering a refrigerator and maybe a few other small things what kind of wires do i need for my battery bank?

[Mike90250]

A 1Kw inverter, on 24v system, should be able to surge 2Kw. At 24V. that's 85A Then you factor the Cable length into that, so that you have less than 3% loss in the cable

using 4 feet from the battery (* Please use one-way distance to the load. Not round trip distance.) I get #6 cable would do the job

http://www.calculator.net/voltage-drop-calculator.html

HOWEVER - looking up the ampacity chart, #6 wire will overheat at 85A, so you must use #4 wire, good for 85A and place no larger than an 85A breaker or fuse on it.

http://www.cerrowire.com/ampacity-charts

If you use fine strand wire, you need special lugs and crimpers rated for fine strand, or buy the wires pre-terminated from a reputable vendor (not always Joes WIre Shack on flea bay)

[texman38]

HOWEVER - looking up the ampacity chart, #6 wire will overheat at 85A, so you must use #4 wire, good for 85A and place no larger than an 85A breaker or fuse on it.)

thanks mike! great info exactly what i'm looking for... the wire has to be the fine strand type or what type is it that takes the regular copper lugs that can be made with an inexpensive crimper sold on ebay for $20... are those acceptable for wiring the batteries and/or inverter???

[texman38]

thanks mike! great info exactly what i'm looking for... the wire has to be the fine strand type or what type is it that takes the regular copper lugs that can be made with an inexpensive crimper sold on ebay for $20... are those acceptable for wiring the batteries and/or inverter???

i just bought 4awg wire, terminals and the crimper, heat shrink... do i need to cancel it?
Color: Red, Black, or 50% Black / 50% Red
Conductor Size: 4 AWG
Length (ft): 5 to 1000 ft
Feet Per Pound: 6.8
Stranding (qty. x dia): 364 / 30
Nominal O.D. (in.): 0.331"
Conductor Material: Copper
Insulation Material: High Grade EPDM
Max. Amps: 150
Max. Voltage: 600
Min. Temperature Rating: -50

[texman38]

Is this the right stuff for making my own battery cables and to inverter?
TEMCo 4 Gauge AWG Welding Lead & Car Battery Cable Copper Wire | MADE IN USA
1/2" heat shrink tube

[texman38]

or do i need these crimpers?

[Richiep]

Hey Texman,
I'm wrestling some of the same questions and also shopping for wire and crimping tools.

The largest wires I'll be using right now is 2AWG so I'm looking at this crimper

https://www.amazon.com/gp/product/B0114QC3OY/ref=crt_ewc_title_huc_3?ie=UTF8&psc=1&smid=A3O4LZF7PHWTGN

And this cutter

https://www.amazon.com/gp/product/B0002YUR70/ref=crt_ewc_title_dp_4?ie=UTF8&psc=1&smid=ATVPDKIKX0DER

Here's a thread I started somewhat related to this subject. It evolved into the importance of good cripms

https://www.solarpaneltalk.com/forum/solar-panels-for-home/solar-panels-for-homes-with-solar-batteries/362647-found-some-4awg-in-my-vehicle-use-it-for-my-control-board

Good Luck!
Rich

[SunEagle]

or do i need these crimpers?

Neither that hammer crimper in your other post or this crimper will get you a proper termination for your wires. You need a hydraulic type crimper similar to the one in Richiep's post but even that one (which I own) will not do the best job on some wires.

If you plan on trying to save money making your own cable then at least look into purchase quality (and expensive) tools.

[Mike90250]

If you insist on making this a DIY, then you must realize you are not going to be making good, reliable connections with the parts & tools you have selected.
Cable is cable.
Lugs are supposed to be tin plated, so the copper does not oxidize and cause high resistance connections
Crimps really need to be done with hydraulic crimper. Look for the 16 ton hydraulic crimper (flea bay) and make sure it has dies for your lugs and cable.
Make sure your die/lug/cable all work together, sacrifice a crimp. Cut it off the cable, clamp the flat part of the lug in a vice, and with a fine blade hacksaw, cut through the middle of the crimp, slowly, gently and carefully. You want to look at the strands inside the crimp. and see if the are fused together and to the shell of the lug. If loose strands fall out, you have a wrong size somewhere.
Ideally, you use certified dies, that imprint their UL code into the lug.
CrimpLugDeformed.jpg

[texman38]

If you insist on making this a DIY, then you must realize you are not going to be making good, reliable connections with the parts & tools you have selected.
Cable is cable.
Lugs are supposed to be tin plated, so the copper does not oxidize and cause high resistance connections
Crimps really need to be done with hydraulic crimper. Look for the 16 ton hydraulic crimper (flea bay) and make sure it has dies for your lugs and cable.
Make sure your die/lug/cable all work together, sacrifice a crimp. Cut it off the cable, clamp the flat part of the lug in a vice, and with a fine blade hacksaw, cut through the middle of the crimp, slowly, gently and carefully. You want to look at the strands inside the crimp. and see if the are fused together and to the shell of the lug. If loose strands fall out, you have a wrong size somewhere.
Ideally, you use certified dies, that imprint their UL code into the lug.
CrimpLugDeformed.jpg

Ok Mike, you are right, and I really dont care to make all of them either (time is money) so would you mind giving me a breakdown of the cables and lengths and gauges needed for my 4 x 6v battery bank? and where to get some UL stamped lugs/wires at an affordable price (i was headed down the path of 2/0 wires, is that too big? not big enough, or just about right? thanks mike, sorry to keep hitting you up for info, you seem like a great guy so thanks

[texman38]

Neither that hammer crimper in your other post or this crimper will get you a proper termination for your wires. You need a hydraulic type crimper similar to the one in Richiep's post but even that one (which I own) will not do the best job on some wires.

If you plan on trying to save money making your own cable then at least look into purchase quality (and expensive) tools.

I think Mike convinced me to buy them... And yes, i saw the 16 ton hydrolic crimpers on ebay for like $35, i think i read the 70mm die would do 2/0, but, I really dont care to make all of them either (time is money) so would you mind giving me a breakdown of the cables and lengths and gauges needed for my 4 x 6v battery bank? and where to get some UL stamped lugs/wires at an affordable price (i was headed down the path of 2/0 wires, is that too big? not big enough, or just about right? thanks Sun Eagle... getting closer... additionally what size wire would i run from my battery bank (4 x 6v in series = 24v) to the power inverter if it were 1000w or 1200w or even 1500w and last if you were to recommend any particular brand or size power inverter? Thanks Sun Eagle!!!

[Mike90250]

I have no idea of the layout of your bank, and what the interconnects are going to be. Map it out, the inverter cables are the ones that end up being critical, because they are usually longer.
Use the caculators I listed in post #4 of this thread, and you can figure it out yourself and run it past us for a sanity check.

[texman38]

I have no idea of the layout of your bank, and what the interconnects are going to be. Map it out, the inverter cables are the ones that end up being critical, because they are usually longer.
Use the caculators I listed in post #4 of this thread, and you can figure it out yourself and run it past us for a sanity check.

Thanks Mike... i will you use probably 2awg for the inverter (as long as it fits... but again the size of the battery cables is still something i need advice on??? 2/0 sound about right? and where do I get reasonably priced UL stamped battery cables? so size and where to buy is what I need advice on? I can figure out the lengths myself, but if they are lined up like in my golf cart there is a very short cable hooking pos to neg, not sure how that would work with 2/0 cabling.... so if you have any suggestions on how to arrange a 4 battery bank so that cabling makes more sense, especially with such thick wires, plz plz plz let me know... Thanks!!!