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Old 02-20-2020, 07:11 PM   #1
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Dual Battery Cable size

I have a 2020 Chateau 27R and i want to upgrade to two batteries. The batteries I intend to use are the Duracell 27DCX, since 6 VDC golf cart batteries won't fit. I'm going to use two 24" cables to wire the batteries in parallel. My question is, what should the AWG of the cable be? Thanks
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Old 02-20-2020, 07:15 PM   #2
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Match or better the size that's feeding your single battery.
The bigger the better, but no less than what feeds your exisitng battery.

The smallest wire in a system is the judge, jury and executioner.
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Old 02-20-2020, 07:30 PM   #3
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It appears that the existing cable is 6 AWG. do you think i should stay with the 6 AWG, or can i go to 4 AWG. thanks
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Old 02-20-2020, 07:43 PM   #4
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I would go as big as I could bend into position.
If you later decide on a 3000w inverter with 350 amp charging, you'll be ready to go.
Crimping ends is going to be crucial no matter the size you use.

While you're in tear up mode I'd redo those 6 cables with bigger.
Most of the labor is already done with the battery tear out.
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Old 02-21-2020, 11:19 AM   #5
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I would just use the #4 gauge wire, that will be more than enough. That wire is rated for 80 amps.
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Old 02-21-2020, 02:43 PM   #6
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When I went to 4-6 volt batteries I used 4 awg. Purchased thru Amazon.
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Old 02-21-2020, 03:40 PM   #7
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I prefer nothing smaller than 2 when connecting GC2
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Old 02-21-2020, 03:46 PM   #8
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Quote:
Originally Posted by wsthomas1 View Post
I have a 2020 Chateau 27R and i want to upgrade to two batteries. The batteries I intend to use are the Duracell 27DCX, since 6 VDC golf cart batteries won't fit. I'm going to use two 24" cables to wire the batteries in parallel. My question is, what should the AWG of the cable be? Thanks
It all depends on the maximum current (amperage) you expect to draw from the battery. In other words, 1/2 of the total expected draw. Typically there is a 50 amp circuit breaker in the converter and the battery bank cable and a 100 amp circuit breaker on the cable to the generator starter motor and the jack motor. So, 4 ga will carry 100 amps (with a 3% loss), but to connect the batteries together, you would only flow 50 amps from each battery; thus the answer would be 6 ga. If you have an 1000 watt inverter, it should have a 100 amp circuit breaker, also; so the answer remains 6 ga is sufficient.
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Old 02-21-2020, 04:07 PM   #9
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Originally Posted by Beau388 View Post
It all depends on the maximum current (amperage) you expect to draw from the battery. In other words, 1/2 of the total expected draw. Typically there is a 50 amp circuit breaker in the converter and the battery bank cable and a 100 amp circuit breaker on the cable to the generator starter motor and the jack motor. So, 4 ga will carry 100 amps (with a 3% loss), but to connect the batteries together, you would only flow 50 amps from each battery; thus the answer would be 6 ga. If you have an 1000 watt inverter, it should have a 100 amp circuit breaker, also; so the answer remains 6 ga is sufficient.
Is sufficient, sufficient, when given a very similar cost alternative?
That is my point. Mine isn't a mathematical solvent. It is a practicality of required labor vs the cost of larger wire and potential future draw solvent.

The labor is the same, the routing is the same, the cost differential is negligible and there is no down side to the larger wire(unless you all know of one that is pertinent.).
Unless you can't afford it, why not upgrade now for the potential 3000w inverter?

My system has a 350a fuse.
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Old 02-21-2020, 04:16 PM   #10
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Originally Posted by lwmcguire View Post
I prefer nothing smaller than 2 when connecting GC2

The answer to the question is entirely different for 6 volt batteries in series vs the OP's 12 volt batteries in parallel.
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Old 02-21-2020, 05:43 PM   #11
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12v Voltage Drop Chart
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Old 02-21-2020, 09:39 PM   #12
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HA! That is what I like about this site, someone asks a simple question and you get a rash of different answers!
Quote:
I have a 2020 Chateau 27R and i want to upgrade to two batteries. The batteries I intend to use are the Duracell 27DCX, since 6 VDC golf cart batteries won't fit. I'm going to use two 24" cables to wire the batteries in parallel. My question is, what should the AWG of the cable be? Thanks
So all that was asked is what AWG is needed to parallel two 12v batteries, 4 ft total.
So the right answer is what Beau388 posted... it is only 4 ft and if there are upgrades later, the OP can deal with larger cable then.
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Old 02-21-2020, 09:47 PM   #13
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Quote:
Originally Posted by wsthomas1 View Post
I have a 2020 Chateau 27R and i want to upgrade to two batteries. The batteries I intend to use are the Duracell 27DCX, since 6 VDC golf cart batteries won't fit. I'm going to use two 24" cables to wire the batteries in parallel. My question is, what should the AWG of the cable be? Thanks
It's just like AC voltage. you must size the wire to the load to be served. You must calculate the wire size per voltage drop using the distance of the wire. See attache voltage chart.

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Old 02-21-2020, 09:51 PM   #14
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Sheeeeeeesh....
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Old 02-27-2020, 02:47 AM   #15
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I purchased a crimp tool, crimp lugs, and 4 gauge welding wire. Custom length on everything. Nice and clean.
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Old 02-27-2020, 11:44 AM   #16
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Where did you pick up the crimp tool? Reasonable price for a one time job? I wonder if I could rent a crimper?
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Old 02-27-2020, 11:46 AM   #17
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Where did you pick up the crimp tool? Reasonable price for a one time job? I wonder if I could rent a crimper?
Most auto parts stores loan/rent tools. I know Advanced does.
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Old 02-27-2020, 12:36 PM   #18
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Quote:
Originally Posted by petefoss View Post
Where did you pick up the crimp tool? Reasonable price for a one time job? I wonder if I could rent a crimper?
Amazon of course. I bought this to crimp lugs for battery cables on my sailboat:

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
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Old 02-27-2020, 04:30 PM   #19
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Where did you pick up the crimp tool? Reasonable price for a one time job? I wonder if I could rent a crimper?

You maybe able to use one from an auto parts store, but I chose to purchase one for round $25 on up. As long as it is a compound or ratchet crimper it will be easy.
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