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Topic: Charging the batteries while towing

Posted By: howardwheeler on 01/25/12 10:18pm

How much charging should I expect while towing my fifth wheel. I have a dual alternator F350 but I can't tell whether much charging is going on while traveling. What connections should I check? By the time I'm done driving for the day it seems the batteries are pulled down quite a bit. I have an inverter to run a residential frig so I need all the help I can get. Maybe I'm wrong but my alternators put out a bunch of amps. I think it's close to 275 amps at 12volts. If I can harness that power and put it in the batteries it seems like I ought to be at least coming close to holding my own while traveling. A frig shouldn't be pulling even a thousand watts. More like 600. What should I look for to determine if my truck is really charging the best it should?


Posted By: pianotuna on 01/25/12 10:34pm

Hi,

You need to beef up the charging path with #4 wire. Voltage drop in the existing wire may only allow 5 to 10 amps at best.


Regards, Don
My ride is a 28 foot Class C, 256 watts solar, 556 amp hours of AGM in two battery banks 12 volt batteries, 3000 watt Magnum hybrid inverter, Sola Basic Autoformer, Microair Easy Start.


Posted By: howardwheeler on 01/25/12 10:45pm

I suppose this would mean changing the pigtail on the trailer if the wire inside is not 4 gauge. What about the trucks wiring to the plug? We used heavy wire when splicing in the seven way in the bed but I don't know about from the alternator to the plug the factory put in the back. That's where we spliced for the inbed plug. Would it make sense to run a separate wire just for the charging? I could put a separate plug in the bed and then a separate wire from the trailer batteries to the bed plug. What typically is the size wire in a large fifth wheels pigtail anyway?


Posted By: garym114 on 01/25/12 10:58pm

The wire size in the connection between the truck and fiver is not large enough to do much charging much less run an inverter. You need to run dedicated wiring from truck battery to fiver battery, positive and negative,negative can go from frame to frame, at least 4 gauge, fused at each end, with an easy way to disconnect when the truck is not running.
It may sound like overkill but on a 12v circuit, 25 feet, 4 AGW wire, 20 amp load the voltage drops to 11.75 volts. Your truck runs at a higher voltage, enough to maintain the fiver batteries between the cycles of the frig.


2000 Sea Breeze F53 V10 - CR-V Toad
Some RV batteries live a long and useful life, some are murdered.
Get a Digital Multimeter and Learn How to Use It



Posted By: PaulJ2 on 01/26/12 01:41am

pianotuna wrote:

Hi,

You need to beef up the charging path with #4 wire. Voltage drop in the existing wire may only allow 5 to 10 amps at best.


I towed a TT with a Chev PU with an installed amp meter in the charging line. The most I saw was 15 amp with a low trailer battery.
Wire was #12 all the way.


Posted By: howardwheeler on 01/26/12 07:37am

Thanks much for the info. I am going to do this modification. I should run all 4 gauge connecting frame to frame for negative fused at both ends and battery positive to battery positive fused. Okay. Pardon my ignorance. What size fuses and what type? What regulation if any is needed? I've never understood charging regulation. Also being a diesel I have two batteries and I have a single bank of four batteries in the Alpenlite. Does it matter where I attach the wires either in the truck or the trailer? I assume on the trailer that I should run the positive to the same terminal as the Xantrex inverter/charger sends its positive to charge. I remember that all the batteries being parallel, you run the positive charging wire off the terminal of the first ( or last) battery and the negative off the terminal on the battery at the opposite end of the chain. Is this correct? If I do this what kind of charging can I expect? I drive sometimes 10 hours at a time. And what happens when the truck is off? What happens if I hook up to shore power? Do I need to make sure to unhook first? I've never even considered that with my present hookup. Sometimes I have left the trailer all hooked up if I'm leaving early in the morning.


Posted By: howardwheeler on 01/26/12 07:39am

Sorry one more question. Do I need to disable the existing charging circuit?


Posted By: enblethen on 01/26/12 07:52am

Upgrading the wire is best way to increase charge rate. No you do not have to change out the connector. Run the large wire to a location close to the connector. Cut the existing wire and splice the new large wire in. The trailer side would not be necessary as there is not much smll wire. Make sure you upgrade the ground connection. Install a properly sized fuse (circuit breaker) in the engine compartment. A 30-40 amp fuse should be enough.
Connect directly to a battey under the hood.
You will need to insulate the cut end of the wire in my option.


Bud
USAF Retired
Pace Arrow

2003 Chev Ice Road Tracker



Posted By: MNtundraRet on 01/26/12 07:53am

You are pointing out one of the real advantages of owning a motor-home over a trailer on any kind.

A motor-home has the alternator connected to the chassis and house-batteries. The cable is usually 0 or 2 gauge. In the case of my Ford V-10 engine and alternator this means 70 AH rate (idling) to 100 AH rate while driving (2000 rpm or higher).

The 7-pin connnector wiring size limits the rate to 5 to 15 AH. Heavier gauge wiring for a truck camper would be easier to modify than a 5th-wheel or travel-trailer.


Mark & Jan "Old age & treachery win over youth & enthusiasm"
2003 Fleetwood Jamboree 29



Posted By: howardwheeler on 01/26/12 08:21am

Which battery on the truck should I connect to? And is any regulation necessary?


Posted By: enblethen on 01/26/12 08:48am

Regulation, no. I would suggest an electrically held relay energized when the ignition switch is in the on position. This would disconnect the trailer when not running to prevent TV from discharging.
I would connect to the battery close to the alternator.


Posted By: pianotuna on 01/26/12 09:00am

Hi,

I can't think why it might be necessary--and it does add a bit of redundancy.

howardwheeler wrote:

Sorry one more question. Do I need to disable the existing charging circuit?



Posted By: BFL13 on 01/26/12 09:46am

IMO the OP will still arrive with the batteries run down some, just not as much. If the object is to run the 120v fridge plus gain or hold on the batteries, a better method is to run a small generator in the truck bed (or the trailer's back bumper) while going down the road, and run a 120v extension cable back to the trailer.

You would need to do a mod for a 120v connection (not for a suicide cord!) at the trailer in the kingpin area that goes to where the fridge is plugged in. Maybe to a transfer switch that feeds the big inverter that goes whole house.


1. 1991 Oakland 28DB Class C
on Ford E350-460-7.5 Gas EFI
See Profile for House electronics set-up.
2. 1991 Bighorn 9.5ft Truck Camper on 2003 Chev 2500HD 6.0 Gas


Posted By: time2roll on 01/26/12 11:41am

I assume you are traveling from one boondock spot to another and want maximum recharge while enroute. Big wire will help but if you really want to crank on the batteries I suggest installing an inverter in the truck and running 120 volts back to the trailer to drive the multistage converter.

Or just leave as is and use a generator more.


2001 F150 SuperCrew
2006 Keystone Springdale 249FWBHLS
675w Solar pictures back up


Posted By: howardwheeler on 01/26/12 06:12pm

The batteries are in the front of the fifth wheel fortunately. How much drop will there be with 4 gauge wire?


Posted By: pianotuna on 01/26/12 06:19pm

Hi,

How many feet to the alternator charging circuit from the battery bank? What voltage from the alternator?

howardwheeler wrote:

The batteries are in the front of the fifth wheel fortunately. How much drop will there be with 4 gauge wire?


* This post was edited 01/26/12 06:26pm by pianotuna *


Posted By: howardwheeler on 01/26/12 01:15pm

I am not expecting to break even just not arrive with depleted batteries. I want to be able to camp the next night without having to plug on. If I need to the next morning I can run my Honda 2000 for a while. Thanks for the help. I've run the wires for the truck and will soon tackle the trailer.


Posted By: mapguy on 01/26/12 01:33pm

You should look at this thread in the Truck Camper Section. Scroll down to the "Camper Electrical" sub section.
Here

Then look for this link. Idea is the same but length and location of wiring/components will be diferent.
Heavy Gauge Charging System (Mathew_B)

There are other examples there too.


Posted By: time2roll on 01/26/12 04:05pm

howardwheeler wrote:

How much charging should I expect while towing my fifth wheel. I have a dual alternator F350 but I can't tell whether much charging is going on while traveling. What connections should I check? By the time I'm done driving for the day it seems the batteries are pulled down quite a bit.

The batteries should not get pulled down while enroute. Check that you have 12v power at the truck connector. Then check the trailer battery voltage should jump up 1/2 volt to 1 volt when you plug into the running truck. I think the existing system may not be working if the batteries are dying enroute. You should get 10 to 20 amps into a low trailer battery although it will taper off after a couple hours.

Ford truck does need a relay installed in the fuse box under the hood to activate the trailer charging circuit. Owner's manual will show the position.


Posted By: mena661 on 01/26/12 04:26pm

smkettner wrote:

The batteries should not get pulled down while enroute.
I think he's got a residential fridge.


2009 Newmar Canyon Star 3205, Ford F53 V10
Trojan L16 6V's 740 Amp-hours



Posted By: time2roll on 01/26/12 04:30pm

Still surprised the batteries are pulled down that much. I would verify the existing system is working properly before pulling new wire.


Posted By: howardwheeler on 01/26/12 04:46pm

Yes I do have a residential frig. The batteries aren't dead after 10 hours but I've lost a lot of amphours per my Linklite. Enough that if I have to run the furnace during the night I drop the batteries too low for my comfort. It just seems a shame to be driving all that time and my super duper twin alternators that cost me hundreds seem to be unengaged.


Posted By: renoman69 on 01/26/12 04:52pm

If your batteries are in the back of the fiver you probably have 60 feet of small wire.


2009 Jayco Eagle Superlite 25.5RKS
2008 Silverado 2500HD Z71 4x4 Duramax/Allison
Reese 15K slider
Honda EU2000I,
270 watts of Kyocera solar
Blue Sky 3024i MPPT controller
450 AHs of Trojan power
Iota DLS-75/IQ4 converter



Posted By: BFL13 on 01/26/12 05:01pm

The OP has a Honda 2000 so it is so easy! Run that in the truck bed and arrange for it to power the trailer's shore power cable by rigging something up as required. Not really difficult.

The Honda 3000 in the bed of the truck runs ok when going down the road and has been used to charge batteries in the bed using a portable charger also in the bed. Would not take much to pass a line back to the trailer to run it via the shore power cord. We just don't need to, so haven't done it.

I have tried various ways to run an inverter in the truck bed via the truck alternator connection with fatter wire, to run the charger instead of using the generator, but it is unsat . It is near 12 ft of wire to go from the front battery down and back under the cab and back up to the bed.

You just can't get anything done amps wise at the other end of 12 ft of DC wire, with the alternator tapering its amps so much as soon as it warms up.

IMO use the Honda 2000 and stop fooling around [emoticon]


Posted By: BFL13 on 01/26/12 06:21pm

Somebody posted elsewhere that you get 1/4 volt drop on 25 ft of #4 at 20amps. However, that takes no account of the alternator's nasty amps tapering you get. You start out at 30 amps or whatever, and in minutes it's down to 15 amps and dropping.

That is why you want to try to run an inverter in the truck bed off those # 4 wires, and run a battery charger from that inverter that does constant amps until the battery acceptance rate forces tapering amps. Which will be delayed or never happen if the fridge is on.

The trick is to see if the wires from battery to inverter will supply enough amps to run the inverter without it alarming off at low voltage. By the time you try everything, you will be back to running the Honda.


Posted By: howardwheeler on 01/26/12 07:26pm

I need an education. Why does the alternator taper off if the batteries still need charging at a bulk rate. The batteries are about four feet back of the tail gate but I'll need a couple of feet more for going up and down. It took 21 feet of 4 gauge to get to the back of the truck so it seems the total will be around 28 feet.


Posted By: mapguy on 01/26/12 07:28pm

howardwheeler wrote:

Yes I do have a residential frig. The batteries aren't dead after 10 hours but I've lost a lot of amphours per my Linklite. Enough that if I have to run the furnace during the night I drop the batteries too low for my comfort. It just seems a shame to be driving all that time and my super duper twin alternators that cost me hundreds seem to be unengaged.


Not sure what year your truck is but why this happens is that alternator senses that the truck batteries are full, then tapers. Trick is to fool the alternator regulator into continuing to think it needs full output still. Check the camper links as they have done this to get better battery bank charging. Technique is little different depending on truck involved. Newer trucks sometimes need the dual alternator wiring modified into 2 seperate systems due to ECM/PCM controlled alternator output. Snow plow forums are also a good source of info for high output charge DC systems.


Posted By: howardwheeler on 01/26/12 07:35pm

I have a 2008 F350 with the dual alternators. It the 6.4 diesel. I thought this would be simple!


Posted By: pianotuna on 01/26/12 07:58pm

Hi,

In other words, one alternator for the chassis and another for the house batteries. The tapering will happen for the chassis alternator but not for the house battery one.

Here is a solution for voltage drop:

Solution:
1 conductor(s) per phase utilizing a 4 kcmil Copper conductor will limit the voltage drop to 4.47% or less when supplying 40 amps for 28 feet on a 14.4 volt system. 0.64 Actual voltage drop loss at 4.47% for the circuit 0.9 Power Factor

voltage drop calculator


Posted By: time2roll on 01/26/12 08:02pm

howardwheeler wrote:

I have a 2008 F350 with the dual alternators. It the 6.4 diesel. I thought this would be simple!

First verify the existing system is working or not.


Posted By: time2roll on 01/26/12 08:07pm

howardwheeler wrote:

I need an education. Why does the alternator taper off if the batteries still need charging at a bulk rate. The batteries are about four feet back of the tail gate but I'll need a couple of feet more for going up and down. It took 21 feet of 4 gauge to get to the back of the truck so it seems the total will be around 28 feet.

Alternator in the truck is primarily designed to recharge a minor battery discharge from starting. Alternator starts at a relatively high ~14.5v but as it warms up will fall back to maybe ~13.8v. Alternator only controls voltage and does not taper the amps. Amps taper based on the drop in voltage. Wire length will further reduce voltage and pretty soon it is a trickle charge even though the alternators are perfectly willing to run near max.

The fat wire will make a big difference.


Posted By: howardwheeler on 01/26/12 08:10pm

Piano tuner, I don't know that a Ford truck like mine has separate circuits for the alternators or how they function. I'd like to know. If one is just for charging house batteries or running something similar then maybe I'd be better off connecting to it. I have already installed the 4 gauge wire into the bed and up to the front but it's not hooked up to the charging system in any way yet. I thought I was just going to hook it up to the battery but now I'm not sure. I used one of those heavy connectors in the bed that are used to connect winches to a truck.


Posted By: mapguy on 01/26/12 08:35pm

howardwheeler wrote:

I have a 2008 F350 with the dual alternators. It the 6.4 diesel. I thought this would be simple!


Not rocket science but you need to taylor your system to work for your demand.

You need to read this thread -these are mostly a little older trucks than yours but basic system and goal is the same is the same -maintain alternator output to the auxiliary circuit after the starting batteries are charged.
Camper Thread Hi Output charge to auxiliary batteries

After understanding the basics -need to research options to make it work on your specific vehicle and dual alt system.


Posted By: mapguy on 01/27/12 08:25am

howardwheeler wrote:

Piano tuner, I don't know that a Ford truck like mine has separate circuits for the alternators or how they function. I'd like to know. If one is just for charging house batteries or running something similar then maybe I'd be better off connecting to it. I have already installed the 4 gauge wire into the bed and up to the front but it's not hooked up to the charging system in any way yet. I thought I was just going to hook it up to the battery but now I'm not sure. I used one of those heavy connectors in the bed that are used to connect winches to a truck.

Stock dual alternator system charges the starting batteries primary and trailer charge line has no load sensing to regulator. Either need to add load sensing to trailer charge line or wire batteries parallel or re-wire one alternator dedicated / independant for trailer charge. What will work depends partly whether PCM/ECM controls alternator charging. I don't know the specifics on this year Ford. All three of these methods are used in vehicle upfitter industry.


Posted By: renoman69 on 01/27/12 09:14am

Not trying to hijack this thread but where does the charging wire go in the trailer. To the battery or to the converter/distribution panel?


Posted By: mapguy on 01/27/12 09:46am

renoman69 wrote:

Not trying to hijack this thread but where does the charging wire go in the trailer. To the battery or to the converter/distribution panel?


Should go to the breakaway brake, then to the batteries.

All the ways to potentially increase amp delivery to an auxiliary use needs a wiring upgrade - 4 gauge or larger for amps OP is talking.


Posted By: time2roll on 01/27/12 09:58am

renoman69 wrote:

Not trying to hijack this thread but where does the charging wire go in the trailer. To the battery or to the converter/distribution panel?
Direct on the battery.


Posted By: BFL13 on 01/27/12 10:06am

Ours goes to the battery via a 40amp glass fuse in the 7-pin's fuse panel by the kingpin where the trailer cord terminates. (All trailer cord wires are fused there except the blue brake wire and the ground wire.)

In the battery compartment there is a path for the 7-pin to feed the converter's line going back to the DC fuse panel, and a path for the 7-pin to run the slide and jacks too.


Posted By: howardwheeler on 01/27/12 10:26am

Mapguy, it is my understanding that on the 2008 Ford the dual alternators are indeed controlled by the PCM. I do not, however, understand the significance of that fact. I don't know about "load sensing" on the trailer charging circuit either. As a matter of fact, you might detect I don't understand a lot of things. It all seemed pretty simple and straightforward at the beginning. But I want an education. I've read the threads in the truck camper forum but still don't have the clear understanding as to the best way to hook up to the truck charging system. I want to put some kind of solenoid in the system. I was even considering running it off my upfitter switches so I could manually turn the heavy duty trailer charging on after the truck gets going. It shuts off when ignition is off. But I haven't thought it all through yet. Thanks for the help thus far.


Posted By: mapguy on 01/27/12 11:10am

BFL13 wrote:

Ours goes to the battery via a 40amp glass fuse in the 7-pin's fuse panel by the kingpin where the trailer cord terminates. (All trailer cord wires are fused there except the blue brake wire and the ground wire.)

In the battery compartment there is a path for the 7-pin to feed the converter's line going back to the DC fuse panel, and a path for the 7-pin to run the slide and jacks too.


Are you sure? As typically there will be a higher amp battery + connection at the PIN Box truck/trailer cable junction box, on a fiver that interfaces with the breakaway switch to energize the brakes from trailer batteries under a breakaway event.


Posted By: mapguy on 01/27/12 11:27am

howardwheeler wrote:

Mapguy, it is my understanding that on the 2008 Ford the dual alternators are indeed controlled by the PCM. I do not, however, understand the significance of that fact. I don't know about "load sensing" on the trailer charging circuit either. As a matter of fact, you might detect I don't understand a lot of things. It all seemed pretty simple and straightforward at the beginning. But I want an education. I've read the threads in the truck camper forum but still don't have the clear understanding as to the best way to hook up to the truck charging system. I want to put some kind of solenoid in the system. I was even considering running it off my upfitter switches so I could manually turn the heavy duty trailer charging on after the truck gets going. It shuts off when ignition is off. But I haven't thought it all through yet. Thanks for the help thus far.


Significance is that you must be careful not to upset (layman terms) the operation of the PCM by your wiring modification methods. Tolerance to shorting and improper loads is small for a PCM. Ambulance and utility truck upfits usually add extra batteries, inverters and other driven equipment -that might be a source of information.

This Ford website may have the info. https://www.fleet.ford.com/truckbbas/

I have done thse type mods on some GM products and older Fords plus class 8. Nothing as new as yours in a Ford.


Posted By: BFL13 on 01/27/12 02:05pm

mapguy wrote:

BFL13 wrote:

Ours goes to the battery via a 40amp glass fuse in the 7-pin's fuse panel by the kingpin where the trailer cord terminates. (All trailer cord wires are fused there except the blue brake wire and the ground wire.)

In the battery compartment there is a path for the 7-pin to feed the converter's line going back to the DC fuse panel, and a path for the 7-pin to run the slide and jacks too.


Are you sure? As typically there will be a higher amp battery + connection at the PIN Box truck/trailer cable junction box, on a fiver that interfaces with the breakaway switch to energize the brakes from trailer batteries under a breakaway event.


Not sure what the question is about, but for the brakes, the trailer cord blue wire from pin #2, goes to the cord's termination near the kingpin where it is not fused like the other wires are. The breakaway switch is mounted nearby on the kingpin and there is a black wire from the blue wire that goes through the breakaway switch to the battery, still not fused. The blue wire changes to black there and goes on to the brakes.


Posted By: mapguy on 01/27/12 02:45pm

Your right we got off topic.
Just making point that trailer charge wire first connction on trailer is to the breakaway switch to provide trailer battery power under a breakaway event. Then continues to the battery. Mine has cb instead of fuse.


Posted By: MNtundraRet on 01/27/12 02:56pm

Judging from your original posts, replies, and admitted ignorance to doing this type of change to your current electrical system, I would suggest there is a good chance you may cause a problem if you go ahead and do this yourself.

I have always had good results with working with our local hitch companies when adding hitches, wiring, to different tow-vehicles and trailers over the years.

At the very least you should copy the your posts and replies, take it along, and check with one of the trailer-hitch installers for upgrading a better electrical connection. They should be able to make sure the work is done correctly. Their work is just as good, or better than most dealers, and cheaper. They make their living at this and do it well.

Do to the fact that many replies here are on different brands, age of equipment,etc., some methods given may not work for your specific system.


Posted By: time2roll on 01/27/12 03:06pm

I see zero risk as long as there is a fuse and the polarity is correct.


Posted By: howardwheeler on 01/27/12 03:30pm

Just got back from the Ford dealer which does a lot of my service, and they emailed Ford about what I'm trying. Ford sent back that I do not have to do anything with the PCM, and I should take the lead right from the battery. I was going to put in a solenoid controlled by my upfitter switches, so I'll manually determine whether the charging circuit is powered. The service tech even showed me four wires Ford puts in the harness that pass through the firewall but aren't hooked to anything. I'll connect one to the upfitter switch wire like I have my tire pressure monitor system, and I'll put a 50 amp circuit breaker right after the battery. I already have one in the rear next to the plug to protect the wiring going both ways. It seems like it will at least be safe. I'm still not sure its the very best way to get large amps to the rear, but it seems like it will be a big improvement.


Posted By: mena661 on 01/27/12 03:44pm

howardwheeler wrote:

I'm still not sure its the very best way to get large amps to the rear, but it seems like it will be a big improvement.
Keep us posted. Take pics if you can.


Posted By: pianotuna on 01/27/12 03:50pm

Hi,

My additional charging path does come right from the battery. I sure wish I had those Hall effect ammeters in place.

I upgraded the oem 60 amp fuse to an automatic circuit breaker--and did the same with my aftermarket "add on" charging path. I chose 50 amps, just to be on the safe side.


Posted By: BFL13 on 01/27/12 03:54pm

mapguy wrote:

Your right we got off topic.
Just making point that trailer charge wire first connction on trailer is to the breakaway switch to provide trailer battery power under a breakaway event. Then continues to the battery. Mine has cb instead of fuse.


Yes, off topic, but I still don't understand. probably a terminology problem. On ours the breakaway power line is an independent line from the battery (no fuse) through the switch to join the blue brake line from the 7-pin cord ( pin #2) that goes to the brakes. It has nothing to do with the "charge line" (pin #4) as such, but they are both on the same battery post as is also the slide power line.


Posted By: mapguy on 01/27/12 05:39pm

howardwheeler wrote:

Just got back from the Ford dealer which does a lot of my service, and they emailed Ford about what I'm trying. Ford sent back that I do not have to do anything with the PCM, and I should take the lead right from the battery. I was going to put in a solenoid controlled by my upfitter switches, so I'll manually determine whether the charging circuit is powered. The service tech even showed me four wires Ford puts in the harness that pass through the firewall but aren't hooked to anything. I'll connect one to the upfitter switch wire like I have my tire pressure monitor system, and I'll put a 50 amp circuit breaker right after the battery. I already have one in the rear next to the plug to protect the wiring going both ways. It seems like it will at least be safe. I'm still not sure its the very best way to get large amps to the rear, but it seems like it will be a big improvement.

Perfect. With PCM/ECM that type of research is needed to avoid expensive complications. I just wasn't absolutely sure. Sounds like your dealer is decent - many don't share or take effort to find out.
Now need to get that heavy gauge wire strung and hung. Suggest using dual conductor plug and sockets like used for a heavy lift gate.


Posted By: howardwheeler on 01/27/12 06:25pm

I had already run the wire from the bed to the engine compartment because I had access to a lift. That made it a lot easier. In the bed I used a connecter like Warn uses to connect their winches to a power source. If I knew how to add pictures I'd try to do so. Where can I read about how to put pictures into the site? I didn't see about those lift gate connectors until I'd already put in the Warn type. It's suppose to carry a lot of amps. I can still change that if necessary. But it looks good.


Posted By: time2roll on 01/27/12 10:05pm

To post a picture you need to share it from a host site such as photobucket
Then paste the pic URL in the pic dialog box from the advanced post form.


Posted By: renoman69 on 01/28/12 08:40am

Still on the "second" topic (should have started a new thread)My fiver has two wires on the positive post and one on the negative.

[image]

White #10 wire goes to the negative post and the black (with the red fuse spliced in) goes to the positive. The orange #12 goes AFAIK to the break away switch. So what the heck is charging these batteries???[emoticon] The large cable going to the left is from my solar controller.


Posted By: mapguy on 01/28/12 12:47pm

renoman69 wrote:

Still on the "second" topic (should have started a new thread)My fiver has two wires on the positive post and one on the negative.

[image]

White #10 wire goes to the negative post and the black (with the red fuse spliced in) goes to the positive. The orange #12 goes AFAIK to the break away switch. So what the heck is charging these batteries???[emoticon] The large cable going to the left is from my solar controller.


Looks like it could be the #12 but you will have to investgate the wiring at the PB located junction/fuse box to make sure. RV Builders do some funky wiring schemes due to how the wire they chassis first then build the box and connect to chassis installed wring & plumbing.


Posted By: enblethen on 01/28/12 01:00pm

The "red" #10 wire should go to the rig's junction box where the TV ambilical cord enters the rig's wiring system. #10 seems awfully small for this run.
I would check to see what size goes to the converter. If it is only #10, I would think about upgrading to what ever the size of the converter plus allowance for voltage drop.
I would also check the size of the negative and do the same for it.


Posted By: BFL13 on 01/28/12 01:28pm

Here is ours from the wiring diagram in the trailer's manual

[image]


Posted By: mapguy on 01/28/12 05:41pm

Mine is similar to BFL13 except the breakaway switch wiring is all at the pin box fuse panel junction box and short lengths. The charge line has a CB instead of fuse installed to protect the trailer.


Posted By: howardwheeler on 02/06/12 06:14pm

I finally had time to finish my project. The wires are all run. I wound up putting 2 gauge from the trailer to the plug in the back of the truck. So I plugged in the regular 7 way and started the truck. With the inverter off and nothing from the truck and all 12 volt loads off I have a .3 amp phantom draw. I read everything off of my Linklite battery monitor. When my wife started the truck with just the 7 way plugged in I jumped up to almost 4 amps going in. I ran my new charging circuit through my number 4 upfitter switch that activates my continuous duty 12 volt solenoid. So I ask my wife to switch on the 4 switch and presto-- at idle almost 30 amps and at 1500 rpm over 40 amps. All the frig draws when running is around 18 amps. So if it works like this going down the road I should have a full battery when I stopped. I'm very pleased. Thanks for the help


Posted By: howardwheeler on 02/06/12 06:30pm

Me, too. I have what seems to be all good crimp connections and screwed the ground from the bed plug to the trailer onto a heavy part of the pin box. Sometime I'd like to figure out if all my connections are done the best way. They are all very solid but I wonder about extra resistance at the connectors. But all is working well. Maybe better than I expected.


Posted By: mena661 on 02/06/12 06:38pm

I wouldn't worry about it. Your alternator amps are more than acceptable.


Posted By: mena661 on 02/06/12 06:19pm

Sweet! Glad it all worked out.


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