cable sizing

[packnrat]

changing to four 6 volt deep cycle batteries. so get to build new cabling.

what is the recomended size for this app? not really up on what size is what, ( i just know a 1/2 in or so od size will out do my needs voltage/amps wise) or good for. aka best for 12 volts. 

longest run will be less than 10 feet. more like only five feet.

and then why not welding cable?  yes i know auto cabling has a harder shell. ( durability for abrasion) and welding cable has finer cabling wire.

[DesertMiner]

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

[packnrat]

so even with 4/0 gauge at 5 feet. i can not get a full 12 volts??

did i work that computer program right?

as i type this my power requriments are not know to me.

it is a small rv, reffer, heater, other? and a cpap. any other over night? and this is after bed time. before would be lights, water pump, other but cpap would be off at that time.

will try and do a proper audit for needs.  but with 4 - 6 volt deep cycle i have more than needed. ( i hope). yes gen during the day.

no hook ups, boon docking. in a area with no noise restrictions. but try to keep the gen to a min at night. just because.

[DesertMiner]

https://www.calculator.net/voltage-drop-calculator.html?material=copper&wiresize=0.1608&voltage=12&phase=dc&noofconductor=1&distance=5&distanceunit=feet&amperes=250&x=67&y=14

[Ronbo]

4/0 cable, 12 volts, it will actually be more, 10 ft distance, 12 amps. The voltage drop will be 0.012 volts.

[packnrat]

i do not know why it is so hard for me to wrap my head around all this. i do get the basics. have not zaped myself with 50K .. yet😜

all the values are geberish to me. but i get if i run 4.0 cable between batteries and converter i am good to go... right.

i try to it the right way, maybe a bit over kill. thinking the 4 6 volts. ground to frame. and to inverter/converter. poscable through a marine cut off switch. via a fuse off the batteries. then on to feed into the coach.

along the way will hook up in a wire to feed from solar.

yes need to buy the correct electronics for this. trying to learn as best as i can.

i know as long as the magic smoke stays in things. i am good to go. 😃

[Chad Heiser]

4/0 cabling will handle your needs with no issue.  I prefer to over build things and I always use 4/0 cable on all the battery banks I build.  You could go down to 2/0 and still be fine, but I prefer the 4/0 for my systems. 

I also always use welding cable when building battery cables.  It is much easier to work with and bends much easier.  Anywhere it passes through something, I always sheath it to prevent any rubbing.

[ALLOY]

I prefer to use tinned marine cable as there is no capacity lost to corrosion over time. If there are tight corners I'll sometimes use Superflex or 2 smaller cables such as two 1/0 wires instead of a single 4/0. 

Having the proper stranding in the cable (22-26ga) ensures the best ( a good crimper is needed) contact between the wire and the inside of the terminal when crimped. 

The temperature rating of the insulation will affect the capacity

 

 

 

 

[Sehc]

Marine cable is best. It is consistent in quality. With welding cable, there is a lot of differences between companies. The inter-connecting cables on the golf cart batteries are important. I recommend having them made commercially, I use GrenuineDealz or BayMarineSupply. GenuineDealz has given me excellent service and quick delivery. 4/0 is heavy. Check that 2/0 will be enough for your expected ampere draw.

It is not good practice to use doubled cables for one circuit. One cable set will always have a different resistance and one cable could carry enough extra to cause a problem.