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Battery Cables

I wanted to "clean up" the starter batteries. I noticed that the positive/negative cables BOTH go into the first battery. According to what I have read here, on past forums, this is a no no. I would like to switch the negative front to back. I may have to order a new length from NAPA. QUESTIONS:  what gauge? what ends?
                                            I have read here that a want military connectors, but the batteries look like they have a different type of hookup. Am I going to have any problems with this modification, especially at the alternator end?
                                            It looks like it won't be a lot of fun, but....I'll take all the advice I can get. Thanks
Glenn and Amy Beinfest
2001 36' U320
#5812
2014 Honda CRV

No Whining on the YACHT

Re: Battery Cables

Reply #1 –
Quote from: GleamB –
I wanted to "clean up" the starter batteries. I noticed that the positive/negative cables BOTH go into the first battery. According to what I have read here, on past forums, this is a no no. I would like to switch the negative front to back. I may have to order a new length from NAPA. QUESTIONS:  what gauge? what ends?
                                            I have read here that a want military connectors, but the batteries look like they have a different type of hookup. Am I going to have any problems with this modification, especially at the alternator end?
                                            It looks like it won't be a lot of fun, but....I'll take all the advice I can get. Thanks
The ends look like GM Delco ends. No way for the military ends for those batteries. If you unscrew one of the ends and there is a 3/8 16 female thread hole then Delco is what the terminals you will need.
1999 40 ft. U-320 wtfe build 5563 Chuck & Lynda's "Rollin' Inn"  2030 watts solar
prev. mh's 71 GMC 5 yrs. 73 Pace Setter 1 yr. 78 Vogue 5 yrs 81 FTX 40ft all electric 18 yrs. 1996 Monaco Signature 3 yrs.
2014 Grand Cherokee Overland
Dream as if you will live forever. Live as if you will die today.  James Dean

Re: Battery Cables

Reply #2 –
Is either the negative cable or positive cable long enough to flip one around?  That should accomplish the same thing with positive on one end and negative on the other.  Or turn the batteries around then maybe one is long enough?
Forest & Cindy Olivier
1987 log cabin
2011 Roadtrek C210P
no longer 1999 36' U320 build #5522
2013 Rzr 570 & 2018 Ranger XP1000
2006 Lexus GX470
2011 Tahoe LT 4x4
Previous 1998 45' 2 slide Newell, 1993 39' Newell

Re: Battery Cables

Reply #3 –
That negative cable looks long enough that you may be able to turn it around.
JohnM.
John & Carm Morales

"We travel not to go anywhere, but to just go.  We travel for travel's sake.  Our great desire is to move."

Re: Battery Cables

Reply #4 –
Quote from: GleamB –
I wanted to "clean up" the starter batteries. I noticed that the positive/negative cables BOTH go into the first battery. According to what I have read here, on past forums, this is a no no.

The only practical improvement, and it's partly theoretical, is to tap the power from the center battery leaving one short lead in either direction, rather than all of the current from the furthest battery traveling through the cable for the middle battery and the first battery.  But at the end of the day, cable size and connection resistance rule.
1992 Foretravel Grand Villa
U225 SBID Build No. 4134
1986 Rockwood Driftwood
1968 S.I.A.T.A. Spring
1962 Studebaker Lark
1986 Honda VF700C
1983 Honda VF750C
Charlie, the Dog was broken out of jail 24 Oct 2023
N1RPN
AA1OH (H)e who must be obeyed.

Re: Battery Cables

Reply #5 –
Cant you put the negative to a bus bar then add another cable? Would it be ok to attach the cable to the frame and then the frame the battery?

Re: Battery Cables

Reply #6 –
The cables from the + and - ends of the connections between your batteries should go to a + and - post inside of your batteries towards the center of the coach.  If they are original cables the should be long enough to go to the opposite corners of the battery pack.  These cables were 3/0 EPDM welding cable on your 2001 coach.

If you have batteries with posts you can put on a military terminals on each one and then use cables with lugs with holes that attach to the military lugs.

If you have batteries with threaded studs then the lugs with holes fit right on to the studs.  You coach came with yellowtop Optima batteries and two short cables for each side that connected the + or - studs together. The main negative connected to one end of the other of the negative side.  The main positive cable connects to the opposite end of the positive side.  For longest battery life swap the battery positions every year or two. The outermost battery goes to the inside.  Ipthe inner most battery goes to the middle.  The middle battery goes to the outside.

Re: Battery Cables

Reply #7 –
Your coach has been like that for 18 years. I'm curious as to why you would wanna change? Asking for a friend.
1994 U280, Build 4490
Deming, NM.

Re: Battery Cables

Reply #10 –
This is more of a little no no (less than ideal) than a big NO NO (won't work). If the engine starts ok, you can live with it.

More important is good clean connections.

I would first try removing the battery end of the negative cable and seeing if it reaches the far battery. If it doesn't reach, remove both ends and take it to an auto parts house and have the longer cable made.

But there is no hurry if it starts ok as is.
Tom Lang K6PG (originally  KC6UEC)
and Diane Lang
2003 38 U295 build 6209
2016 Jeep Grand Cherokee Summit Ecodiesel
still have tow-ready 2006 Acura MDX 
Temple City, California
Motorcade 16681 California Chapter President
SKP 16663 member of SKP Park of the Sierra, Coarsegold California
FMCA F071251
Retired electrical and electronic engineer

Re: Battery Cables

Reply #11 –
Quote from: Twig –
Your coach has been like that for 18 years. I'm curious as to why you would wanna change? Asking for a friend.

As I first noted, I had read, on this forum, that it is a bad idea to have the pos and neg going into the first battery, as a failure in that battery would screw up the other two. I am not an expert on these matters. The coach " labors " when you first hit the key....the PO told me it always did, for him, and always started. I want to be Proactive in caring for my coach, especially since we are getting ready for our return trip to Mazatlan, sans my favorite traveling amigo. If you get what I mean......
Glenn and Amy Beinfest
2001 36' U320
#5812
2014 Honda CRV

No Whining on the YACHT

Re: Battery Cables

Reply #12 –
No matter how it's wired, a failure of one battery will screw up the other two.

When I first got my coach, I noticed the start batteries wouldn't start without using the boost switch if the coach had been sitting for a few days.

I disconnected all three batteries and measured their voltages. One was two volts lower than the others, it had a shorted cell and was constantly discharging the good batteries.

I disconnected the bad battery and ran with just two good batteries until I could get a replacement.

So ... while you are cleaning up the cables, test the battery voltages.
Tom Lang K6PG (originally  KC6UEC)
and Diane Lang
2003 38 U295 build 6209
2016 Jeep Grand Cherokee Summit Ecodiesel
still have tow-ready 2006 Acura MDX 
Temple City, California
Motorcade 16681 California Chapter President
SKP 16663 member of SKP Park of the Sierra, Coarsegold California
FMCA F071251
Retired electrical and electronic engineer

Re: Battery Cables

Reply #13 –
In a list of things to do that make you feel good but actually don't solve any problem, rewiring your battery cables would be at or near the top.

I work in an industry that has HUGE battery banks with hundreds of batteries wired together in series and parallel for UPS safety-of-life systems.  None of the equal cable length nonsense rule is followed.
1998 U270 34'

Re: Battery Cables

Reply #14 –
When I was running cable for my 10 battery - 6V battery bank is was concerned about getting all the cable lengths equal.
During a conversation with Alan at Bay Marine I expressed my concerns.
He told me that exact equal length was NOT needed. The practical, mathematical difference when running 4 gauge cable is insignificant  if one cable is a few inches longer or shorter than another.
I strived to keep the cables equal but don't lose sleep over having a couple 6" longer than the others.
1995 U320C SE 40'
Jeep 4x4 Commander - Limited - Hemi
"The Pack"  Yogi and Diesel our Airedales -  Charlie our Boxer/Akita mix. Gone but NEVER forgotten Jake our yellow Lab.
NRA Law Enforcement Firearms instructor - Handgun/shotgun
Regional Firearms instructor for national Armored Transp. Co.