Battery not charging while towing

[redbarron55]

As the brake coils warm up they will draw less amps, but the controller corrects for this automatically.
If you are using the brakes enough to make a difference then something is very wrong.


Sent from my SCH-I605 using Fiberglass RV mobile app

[gordon2]

Originally Posted by Darral T.

...
ok ok...I understand that you're going to lose it inefficiently during the step-down (resistance) from 120v to 12v and converting ac/dc....yada yada....but it is a "fun" thought.

Well as long as we are having fun!

But I am a little confused with the discussion about the brakes. If you are thinking about total load on the tug's alternator, then I get that the power draw from the brakes is something to consider and can be part of the reason if the tug's battery is being discharged while towing.

But if you are talking about the available power on the charge line, then I am confused because the charge line is (typically) a separate wire directly form the tug's battery. If the charge line is enough to keep the trailer battery going (maybe while running the fridge), has nothing to do with the brakes as long as the alternator can supply enough power for both, as well as the lights, keeping the tug's battery charged, and any other power draw.

[EllPea in CA]

Originally Posted by gordon2

Well as long as we are having fun!

But I am a little confused with the discussion about the brakes. If you are thinking about total load on the tug's alternator, then I get that the power draw from the brakes is something to consider and can be part of the reason if the tug's battery is being discharged while towing.

But if you are talking about the available power on the charge line, then I am confused because the charge line is (typically) a separate wire directly form the tug's battery. If the charge line is enough to keep the trailer battery going (maybe while running the fridge), has nothing to do with the brakes as long as the alternator can supply enough power for both, as well as the lights, keeping the tug's battery charged, and any other power draw.

Well, I AM having fun, but with this last paragraph I'm now officially brain dead.

[Darral T.]

Steve B. actually mentioned the "Charge wire". I agree that it's only going to the battery (HOT wire) on the Scamp. BUT, my thinking was (and I didnt catch the "charge wire") that they were thinking TOTAL amps being pulled from the alt. when the brakes were asked to be "considered". But, I was more concerned about my fridge and didnt get to check the amps on it tonight like I wanted.

Anyway, since the brakes are an intermittent draw and not as constant as the fridge would be and if I was figuring how many amps I'm going to be pulling with, I wouldnt even figure in the brakes- UNLESS- you're going to be pulling in town/heavy stop-n-go traffic.

FWIW, when I ran my wires to the rear of my truck, I have two 10ga lines- one for the brakes and one for the "hot" wire. There's two separate breakers for each under the hood of my truck. One is 40A (Hot or Black wire on trailer) and the other a 20A breaker (brakes or blue wire on trailer). They automatically reset.

Originally Posted by gordon2

Well as long as we are having fun!

But I am a little confused with the discussion about the brakes. If you are thinking about total load on the tug's alternator, then I get that the power draw from the brakes is something to consider and can be part of the reason if the tug's battery is being discharged while towing.

[gordon2]

Originally Posted by Darral T.

....
FWIW, when I ran my wires to the rear of my truck, I have two 10ga lines- one for the brakes and one for the "hot" wire. There's two separate breakers for each under the hood of my truck. One is 40A (Hot or Black wire on trailer) and the other a 20A breaker (brakes or blue wire on trailer). They automatically reset.

Yes, two wires...

But I wonder about the auto-reset breakers instead of fuses. I know that auto-reset breakers are recommended for the brake line, apparently under the theory that if you have a temporary overload and the breaker trips, then the auto-reset will restore your braking ability.

However, unless I have something very wrong, your 20 amp breaker is rated at more than twice the maximum possible draw for the brakes on a Scamp or any other single axle fiberglass trailer.

Therefore the breaker (or 20 amp fuse if used instead of a breaker) should NEVER trip (or fuse blow) unless there is a problem in the wiring such as a short to ground. And if there is short to ground, do you really want to re-energize the circuit and take of chance of doing damage to the wiring? After all, the wiring is a PIA to run if if needs to be replaced.

My brake controller indicates if there there is a loss of power (or ground), or a loss of connection to the trailer. In those cases I know I have to stop the rig with the tug's brakes alone, and by downshifting. So, I would stop as soon as possible and investigate the fault. That happened once when I bottomed out and the trailer's plug popped out - it was no big deal.

I guess there is always a slim chance that a resetting breaker would restore the trailer's brakes long enough to pull over safely whereas a blown fuse would not, however, IMHO the only logical reason for the breaker to trip is a wiring fault that is just as likely to leave you without trailer brakes anyway, and perhaps cause permanent damage to the wiring also if the breaker keeps coming back on. I would also think that a breaker is more trouble prone or subject to defect than a fuse.

So, for the record, follow the manufacture's directions for circuit protection when installing a brake system. If they call for auto-reset breakers, as most do, then that is what you should do. My comments are only for discussion.

But the logic fails me, at least for this application, and I am comfortable with my 20 amp fuse for the trailer brake line.

BTW, for me, the charge line should always be a fuse and not a resetting breaker. The worst case scenario for loss of power on the charge line is a dead trailer battery and spoiled food in the fridge - quite a bit different than loss of brakes. On the other hand, continuously re-energizing a 40 amp charge line that is shorting out, perhaps under the tug, near the tug's gas tank or near the trailer's propane tanks, is not something I would want to do.

In either case, I want to find out why the fuse is blowing (or breaker tripping) and fix the problem before re-energizing the wiring.

YMMV.

[Darral T.]

Good points Gordon. I argued the same with etrailer. I can understand the "fuse" on the "hot" side. Of course the way it was explained on the brake side, IF you're going down a mountain, do you want to lose brakes TOTALLY? Well obviously, we'd both emphatically would say "NO".

In reality and all honesty? This was my FIRST experience with personal RV towing, brake controllers, 7-pin connections etc. (Growing up, we had a home-built motor home my dad built) I BELIEVE my setup (from etrailer) came with a 30A breaker as well and I agree that it should be on the "Hot" side as MAX since the wiring could be an issue at 40A. I think I know where it's at and will look it up. But for 6 yrs- "out of site out of mind" since I've had no issues. I agree that a fuse would be safer all the way around on the "Hot" side....but I would still leave the breaker on the brakes.

As far as the wiring, that's one advantage of doing it yourself. I made SURE that my wires from the battery were NOT going near any fuel lines OR gas tank and are run along the outside of my truck frame and zip tied...that I'm 100% positive... So maybe I did something right.

I did tell the wife years ago, that my NEXT "tow" vehicle WILL be wired and "fired" from the factory.... That was a big job for one person.

This is a FWIW....doing a little "searching"... I wonder how many knows that a DEAD SHORT can go to over 1500-2000A on a 12v circuit? And, the "Locked Amps" on my Coleman A/C are nearly 50A! I'll throw this in then run away for awhile... but Scamp put 14Ga wire on my A/C when Coleman CLEARLY "specs" 12Ga. I called Kent Eveland's hand on it and his comment was "That's the way we've always done it". Sighhh. As my wife has said since the beginning of our 6 yrs of camping- "RVing is not for the faint-hearted". I agree!

Originally Posted by gordon2

Yes, two wires...

But I wonder about the auto-reset breakers instead of fuses. I know that auto-reset breakers are recommended for the brake line, apparently under the theory that if you have a temporary overload and the breaker trips, then the auto-reset will restore your braking ability.
.......
In either case, I want to find out why the fuse is blowing (or breaker tripping) and fix the problem before re-energizing the wiring.

YMMV.

[gordon2]

Originally Posted by Darral T.

... Of course the way it was explained on the brake side, IF you're going down a mountain, do you want to lose brakes TOTALLY? Well obviously, we'd both emphatically would say "NO". ...

Well the only scenario I can possible imagine where you would trip the breaker, and it would reset, and then you would have full brakes (for a time) is an intermittent short.

Say that the insulation on your brake hot wire gets worn off from repeated abrasion in the area where is is next to the vehicle frame. Now say that, every once in a while you hit a bump and at the same time have the trailer's brakes activated, so the short to ground trips the breaker.

Now, the circuit breaker cycles continuously during over-current condition, so maybe when the wire is shorted, some current will get to the brakes, but maybe not depending on how bad the short is.

If you are paying attention, perhaps you will notice the problem on the display of your brake controller. But after you go over the bump, if the wire is no longer shorted out, then things return to "normal" and you have no clue that you have a problem. That is, at least until the short gets so bad that you have no brakes at all. But at least until then you have brakes when using the reset breaker (but not a fuse).

If normal operation of our trailer brakes occasional created an overload, then that would be a different situation. But as I see it (again, for the trailers in discussion at least) anytime the circuit breaker trips it indicates a fault that should be corrected right away. The auto-reset feature can mask that fault however.

I did buy one of the Pollak auto-reset breakers from etrailer but the mounting tab broke off when I went to install it. So I ordered another one, and the same thing happened. So I have a fuse now instead.

I'm with you on the DIY route. I am sure I did at least as good a job, and more likely a better job, than some "pro" who needs to make a living and so works fast with less than the top quality parts. And having it done "right" is the most important thing to keeping your brakes working. But what a PIA it was. At least I can have confidence in it but I also plan to inspect it annually (wire ties don't last forever!)

And BTW, forget about any help from Toyota (for a Sienna) even though they market the van for towing up to 3500 lbs. But in practice, they offer NO support for anything towing related nor do they endorse any after-market stuff. Next time it's a tug that really is ready to tow, pre-wiring and all.

[Carol H]

Originally Posted by Ellpea in CA

Well, I AM having fun, but with this last paragraph I'm now officially brain dead.

:lout:lout Your not on your own One of those situations where the answer to your problem has become over complicated.

To keep it simple the answer to your original question is the fridge is most probable pulling more power than what your vehicle charge line is capable of providing to the battery and the more hours you tow and the warmer the weather the lower the battery state will be at destination .... thats my answer and I am sticking to it

[Kkightly]

Carol H. Thank you for the quick answer to the original question. My head hurts after reading all the info about the battery, wires, amps, volts. I have a Scamp 13, pulled with a 4 cyc Ford Escape. I have the same issue - full battery - drained when I arrive at the camp site when on battery power. I tried running with the fridge on propane while driving. The pilot is alway off when I arrive. My next solution is to keep a couple frozen bottles of water in the fridge, no propane or battery power and keep my fingers crossed and door to the fridge closed until I get to my camp site.
Thanks everyone for the info - most of it was way over my head. So I'm picking a simple solution.
Kelly

[Darral T.]

The OP asked for "any ideas?" and alot of us threw as many out as possible. In the past post or 2, I see the "problem" restated but no "solution" either. Only the OP can take what's been posted and try to rectify/troubleshoot it if desired...over their head or not. If one is not willing to test some of the potential "trouble areas" we stated? Then the "simple solution" in MY opinion is to use a "cooler".

Originally Posted by Kkightly

Carol H. Thank you for the quick answer to the original question. My head hurts after reading all the info about the battery, wires, amps, volts. I have a Scamp 13, pulled with a 4 cyc Ford Escape. I have the same issue - full battery - drained when I arrive at the camp site when on battery power. I tried running with the fridge on propane while driving. The pilot is alway off when I arrive. My next solution is to keep a couple frozen bottles of water in the fridge, no propane or battery power and keep my fingers crossed and door to the fridge closed until I get to my camp site.
Thanks everyone for the info - most of it was way over my head. So I'm picking a simple solution.
Kelly

[stevebaz]

You have limited resource. (the cars alternator) it feeds the car's battery and all the car's electrical consumption as it was designed to do. You now have a trailer and the trailer has needs( in this case the frige, and the trailer brakes and anything else you leave on in the trailer when you travel) the trailer draws power from the trailer battery. You hitch up your trailer to the car and the trailer starts pulling its power needs from the car. If the wire between the trailer battery and the car's battery is too small the power from the car's battery will not get to the trailer battery in time to meet the demand being put on the trailer's battery and the battery in the trailer will run down.

If the connection between the trailer's battery and the car's battery is large enough the trailer battery will draw the power it needs from the car's battery. If the alternator is too small in the car it will not refill the trailer's battery and the car's battery and both batteries will run down. There are small alternators and larger alternators. They both provide power in variable amounts depending on engine speed. There is also the situation when you stop and turn off the motor in the car the electrical draw from the trailer will continue to draw power from both batteries until you use a means to separate the power from the draw on both batteries. If improperly set up you can stop for lunch with the engine off and the electrical draw from the trailer continues and can deplete both batteries and you will be unable to restart your car.

We are trying to help direct the original poster to where the problem may lie. We have nothing to go with from the original post to direct us other than her trailer battery isnt keeping up while under tow with the fridge on using 12 volts.

If everything was set up properly they shouldn't have this problem. It is obvious something has to change in their setup to accomplish the task they put before us.

[Carol H]

Originally Posted by Kkightly

My next solution is to keep a couple frozen bottles of water in the fridge, no propane or battery power and keep my fingers crossed and door to the fridge closed until I get to my camp site.
Thanks everyone for the info - most of it was way over my head. So I'm picking a simple solution.
Kelly

That solution worked will for me in my old Scamps fridge for 9 years of extensive travel. The propane pilot light would not stay light when traveling on it either! I did use a cooler for items that needed to be frequently gotten at such as drinks to keep the opening and closing of the fridge down to a min.

Happy that the installation of the fridge on my new to me trailer is designed to permit the propane to run while traveling without the flame blowing out. Just have to remember now to turn it off before refuelling at a gas station.

[EllPea in CA]

Originally Posted by Carol H

:lout:lout Your not on your own One of those situations where the answer to your problem has become over complicated.

To keep it simple the answer to your original question is the fridge is most probable pulling more power than what your vehicle charge line is capable of providing to the battery and the more hours you tow and the warmer the weather the lower the battery state will be at destination .... thats my answer and I am sticking to it

Thank you, my dear. My head still hurts, but I'm feeling better!

[Darral T.]

And is your fridge any cooler?????????????

Originally Posted by Ellpea in CA

Thank you, my dear. My head still hurts, but I'm feeling better!

[Carol H]

Originally Posted by Darral T.

And is your fridge any cooler?????????????

:lout:lout As I said there is a bit of over complicating of the problem going on here. ;-)

OP never indicated the fridge was not working and/or was not cold.... simple that her battery had not been charged up as expected.

[EllPea in CA]

Originally Posted by Carol H

:lout:lout As I said there is a bit of over complicating of the problem going on here. ;-)

OP never indicated the fridge was not working and/or was not cold.... simple that her battery had not been charged up as expected.

AND... Thank you again!

(Currently fridge is quite warm, because we aren't hooked up to ANYTHING)

[Darral T.]

So now the simple solutions has the battery FULLY charged when they arrive at the next destination? Yall oughta seek work at NASA....Mars needs you!

Originally Posted by Carol H

:lout:lout As I said there is a bit of over complicating of the problem going on here. ;-)

OP never indicated the fridge was not working and/or was not cold.... simple that her battery had not been charged up as expected.

[Mr Lynn]

It is concerning for many of us who buy new or recent-model trailers and tow vehicles (in many cases with factory-installed tow packages) to read that the trailer and/or the TV wiring is not adequate to meet the demands of installed appliances—especially in small, easy-to-tow MFG trailers.

While I certainly could spend many hours crawling around under my TV and trailer stringing new wires, fuses, etc., I really have other demands on my time, and rather expected that the state-of-the-art systems in my late-model Casita and Ford Expedition would be more than adequate for our modest needs.

It can be rewarding to remedy minor deficiencies or oversights (like no springs on the screen door), or to personalize with mats and curtains, etc., but should I have to assume that my vehicles are just not adequate to the tasks they were designed for?

/Mr Lynn

[Carol H]

Originally Posted by Darral T.

So now the simple solutions has the battery FULLY charged when they arrive at the next destination? Yall oughta seek work at NASA....Mars needs you!

Now that the OP knowns the cause of the problem and the various ways to address it, I have little doubt that they will indeed arrive at their next destination with a full battery.

I know it may be hard for some to believe but many woman are very capable of trouble shooting and understanding issues with their trailers and fixing them, as well as design and build a space shuttle.

BTW its actually men who are said to be better suited to Mars.

[Glenn Baglo]

Do you blame your bank if your ATM withdrawals total more than your deposits?

Running the fridge on 12V while traveling is just not efficient. How many people want to pay for upgraded wiring, batteries and alternator that they don't need?