Foretravel Owners' Forum

Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: GleamB on September 06, 2019, 04:19:12 pm

Title: Battery Cables
Post by: GleamB on September 06, 2019, 04:19:12 pm
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
Title: Re: Battery Cables
Post by: craneman on September 06, 2019, 04:24:13 pm
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.
Title: Re: Battery Cables
Post by: folivier on September 06, 2019, 06:43:30 pm
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?
Title: Re: Battery Cables
Post by: John Morales on September 06, 2019, 07:04:57 pm
That negative cable looks long enough that you may be able to turn it around.
JohnM.
Title: Re: Battery Cables
Post by: Old Toolmaker on September 06, 2019, 08:58:12 pm
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.
Title: Re: Battery Cables
Post by: DavidS on September 06, 2019, 09:02:32 pm
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?
Title: Re: Battery Cables
Post by: Roger & Susan in Home2 on September 06, 2019, 09:36:09 pm
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.
Title: Re: Battery Cables
Post by: Twig on September 06, 2019, 10:29:54 pm
Your coach has been like that for 18 years. I'm curious as to why you would wanna change? Asking for a friend.
Title: Re: Battery Cables
Post by: Roger & Susan in Home2 on September 06, 2019, 10:56:44 pm
Twig, those are not the original batteries in Glen;'s coach or the originally wiring.
Title: Re: Battery Cables
Post by: DavidS on September 06, 2019, 11:01:06 pm
Twig, those are not the original batteries in Glen;'s coach or the originally wiring.
Cmon now.. how would his friend know that? ;)  lol

Back to the grounds.. wouldnt a bus bar work or no?
Title: Re: Battery Cables
Post by: Tom Lang on September 07, 2019, 05:42:31 am
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.
Title: Re: Battery Cables
Post by: GleamB on September 07, 2019, 10:30:09 am
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......
Title: Re: Battery Cables
Post by: Tom Lang on September 07, 2019, 11:29:33 am
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.
Title: Re: Battery Cables
Post by: krush on September 08, 2019, 11:25:48 am
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.
Title: Re: Battery Cables
Post by: Lon and Cheryl on September 08, 2019, 05:47:14 pm
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.